# Graphene oxide based integrated nanophotonic polarizers in silicon-on-insulator devices

David Moss

<figure><img src="image_1.png" /></figure>

## To cite this version:

David Moss. Graphene oxide based integrated nanophotonic polarizers in silicon-on-insulator devices. 2024. hal-04605660

HAL Id: hal-04605660

https://hal.science/hal-04605660

Preprint submitted on 7 Jun 2024

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_2.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Graphene oxide based integrated nanophotonic polarizers in silicon-on-insulator devices

David Moss

<figure><img src="image_1.png" /></figure>

## To cite this version:

David Moss. Graphene oxide based integrated nanophotonic polarizers in silicon-on-insulator devices. 2024. hal-04605660

HAL Id: hal-04605660

https://hal.science/hal-04605660v1

Preprint submitted on 7 Jun 2024

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_2.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
Graphene oxide based integrated nanophotonic polarizers in
silicon-on-insulator devices

David J. Moss¹, a)

¹ Optical Sciences Centre, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia

a) dmoss@swin.edu.au

**Abstract**

We experimentally demonstrate waveguide and microring resonator (MRR) polarizers by integrating 2D graphene oxide (GO) films onto silicon (Si) photonic devices. The 2D GO films with highly anisotropic light absorption are on-chip integrated with precise control over their thicknesses and sizes. Detailed measurements are performed for the fabricated devices with different GO film thicknesses, coating lengths, and Si waveguide widths. The results show that a maximum polarization-dependent loss (PDL) of ~17 dB is achieved for the hybrid waveguides, and the hybrid MRRs achieved a maximum polarization extinction ratio (PER) of ~10 dB. We also characterize the wavelength- and power-dependent response for these polarizers. The former demonstrates a broad operation bandwidth of over ~100 nm, and the latter verifies performance improvement enabled by photo-thermal changes in GO films. By fitting the experimental results with theoretical simulations, we find that the anisotropy in the loss of GO films dominates the polarization selectivity of these devices. These results highlight the strong potential of 2D GO films for realizing high-performance polarization selective devices in Si photonic platform.

Keywords: graphene oxide, polarizers, silicon, nanophotonics
Graphene oxide based integrated nanophotonic polarizers in
silicon-on-insulator devices

David J. Moss¹, a)

¹ Optical Sciences Centre, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia

a) dmoss@swin.edu.au

Abstract

We experimentally demonstrate waveguide and microring resonator (MRR) polarizers by integrating 2D graphene oxide (GO) films onto silicon (Si) photonic devices. The 2D GO films with highly anisotropic light absorption are on-chip integrated with precise control over their thicknesses and sizes. Detailed measurements are performed for the fabricated devices with different GO film thicknesses, coating lengths, and Si waveguide widths. The results show that a maximum polarization-dependent loss (PDL) of ~17 dB is achieved for the hybrid waveguides, and the hybrid MRRs achieved a maximum polarization extinction ratio (PER) of ~10 dB. We also characterize the wavelength- and power-dependent response for these polarizers. The former demonstrates a broad operation bandwidth of over ~100 nm, and the latter verifies performance improvement enabled by photo-thermal changes in GO films. By fitting the experimental results with theoretical simulations, we find that the anisotropy in the loss of GO films dominates the polarization selectivity of these devices. These results highlight the strong potential of 2D GO films for realizing high-performance polarization selective devices in Si photonic platform.

Keywords: graphene oxide, polarizers, silicon, nanophotonics
Optical polarizers transmit light only polarised in one direction while blocking perpendicularly polarized light. They are important functions for modern optical systems.[1, 2] They have facilitated polarization selection and control in a wide range of applications, such as optical sensing,[3, 4] imaging and display,[5, 6] optical analysis,[7, 8] and optical communications.[9, 10]

A variety of optical polarizers have been implemented based on different bulk material device platforms, such as refractive prisms,[11, 12] birefringent crystals,[13, 14] fiber components,[15, 16] and integrated photonic devices.[17, 18] Amongst these, integrated photonic polarizers, particularly those based on the well-developed silicon (Si) photonic platform, offer attractive advantages of compact footprint, low power consumption, and the capability for large-scale manufacturing. Nevertheless, the rapid advancement of photonics industries drives the demand for high-performance optical polarizers across broad wavelength ranges, which is usually challenging for optical polarizers based on bulk materials.[19-21]

Recently, owing to their high anisotropy in light absorption and broadband response, 2D materials, such as graphene,[22, 23] graphene oxide (GO),[24, 25] transition-metal dichalcogenides (TMDCs),[26, 27] and black phosphorus,[28] have been on-chip integrated to realize optical polarizers with high performance and new features. As a common derivative of graphene, GO with facile fabrication processes for precise on-chip integration shows a high compatibility with integrated device platforms.[29-31] Previously, we reported high performance waveguide and microring resonator (MRR) polarizers by integrating 2D GO films onto high index doped silica devices.[25] In this work, we further integrate 2D GO films onto the more widely used Si photonic devices to realize waveguide and MRR polarizers. Precise control of the GO film thicknesses is achieved by using a transfer-free and layer-by-layer film coating method,
Optical polarizers transmit light only polarised in one direction while blocking perpendicularly polarized light. They are important functions for modern optical systems.[1, 2] They have facilitated polarization selection and control in a wide range of applications, such as optical sensing,[3, 4] imaging and display,[5, 6] optical analysis,[7, 8] and optical communications.[9, 10]

A variety of optical polarizers have been implemented based on different bulk material device platforms, such as refractive prisms,[11, 12] birefringent crystals,[13, 14] fiber components,[15, 16] and integrated photonic devices.[17, 18] Amongst these, integrated photonic polarizers, particularly those based on the well-developed silicon (Si) photonic platform, offer attractive advantages of compact footprint, low power consumption, and the capability for large-scale manufacturing. Nevertheless, the rapid advancement of photonics industries drives the demand for high-performance optical polarizers across broad wavelength ranges, which is usually challenging for optical polarizers based on bulk materials.[19-21]

Recently, owing to their high anisotropy in light absorption and broadband response, 2D materials, such as graphene,[22, 23] graphene oxide (GO),[24, 25] transition-metal dichalcogenides (TMDCs),[26, 27] and black phosphorus,[28] have been on-chip integrated to realize optical polarizers with high performance and new features. As a common derivative of graphene, GO with facile fabrication processes for precise on-chip integration shows a high compatibility with integrated device platforms.[29-31] Previously, we reported high performance waveguide and microring resonator (MRR) polarizers by integrating 2D GO films onto high index doped silica devices.[25] In this work, we further integrate 2D GO films onto the more widely used Si photonic devices to realize waveguide and MRR polarizers. Precise control of the GO film thicknesses is achieved by using a transfer-free and layer-by-layer film coating method,
together with window opening on the upper cladding of Si photonic devices to control the film
coating lengths. We perform detailed measurements for the fabricated devices with different
GO film thicknesses, coating lengths, and Si waveguide widths, achieving a maximum
polarization-dependent loss (PDL) of ~17 dB for the waveguide polarizers and a maximum
polarization extinction ratio (PER) for the MRR polarizers. The wavelength- and power-
dependent response of these polarizers is also characterized, showing a broad operation
bandwidth over ~100 nm and improvement in the polarization selectivity enabled by photo-
thermal changes in GO films. Finally, we perform theoretical analysis by fitting the
experimental results with theory, which reveals that the anisotropy in the loss of GO films
dominates the polarization selectivity of these polarizers. These results verify the effectiveness
of integrating 2D GO films onto Si photonic devices for implementing high-performance
optical polarizers.

**Figure 1(a)** illustrates the atomic structure of monolayer GO, in which the carbon network is decorated with diverse oxygen functional groups (OFGs) such as epoxide, hydroxyl, and carboxylic groups.[32, 33] Unlike graphene that has a zero bandgap and exhibits metallic behavior,[34] GO is a dielectric material with an opened bandgap typically ranging between ~2.1 and ~3.6 eV.[30, 32] This bandgap is larger than the energy of two photons at 1550 nm (i.e., ~1.6 eV), which yields both low linear light absorption and two-photon absorption (TPA) in the telecom band.
together with window opening on the upper cladding of Si photonic devices to control the film
coating lengths. We perform detailed measurements for the fabricated devices with different
GO film thicknesses, coating lengths, and Si waveguide widths, achieving a maximum
polarization-dependent loss (PDL) of ~17 dB for the waveguide polarizers and a maximum
polarization extinction ratio (PER) for the MRR polarizers. The wavelength- and power-
dependent response of these polarizers is also characterized, showing a broad operation
bandwidth over ~100 nm and improvement in the polarization selectivity enabled by photo-
thermal changes in GO films. Finally, we perform theoretical analysis by fitting the
experimental results with theory, which reveals that the anisotropy in the loss of GO films
dominates the polarization selectivity of these polarizers. These results verify the effectiveness
of integrating 2D GO films onto Si photonic devices for implementing high-performance
optical polarizers.

**Figure 1(a)** illustrates the atomic structure of monolayer GO, in which the carbon network is decorated with diverse oxygen functional groups (OFGs) such as epoxide, hydroxyl, and carboxylic groups.[32, 33] Unlike graphene that has a zero bandgap and exhibits metallic behavior,[34] GO is a dielectric material with an opened bandgap typically ranging between ~2.1 and ~3.6 eV.[30, 32] This bandgap is larger than the energy of two photons at 1550 nm (i.e., ~1.6 eV), which yields both low linear light absorption and two-photon absorption (TPA) in the telecom band.
<figure><img src="image_3.png" /><figcaption>FIG. 1. (a) Schematic of GO's atomic structure. (b) Schematic illustration of a waveguide optical polarizer based on a Si waveguide integrated with a monolayer GO film. Inset illustrates the layered structure of GO films fabricated by the self-assembly method. (c) TE and TM mode profiles for the hybrid waveguide in (b). (d) Microscopic image of the fabricated devices on a silicon-on-insulator (SOI) chip coated with a monolayer GO film. (e) Measured Raman spectra of the SOI chip in (d) before and after coating the GO film.</figcaption></figure>

**Figure 1(b)** shows the schematic of a Si nanowire waveguide integrated with a monolayer GO film. The corresponding transverse electric (TE) and transverse magnetic (TM) mode profiles for the hybrid waveguide are shown in **Fig. 1(c)**, which were simulated using a commercial mode solving software (COMSOL Multiphysics). The width and height of the Si waveguide are 400 nm and 220 nm, respectively. Due to the interaction between the evanescent field from the Si waveguide and the 2D GO film with strong anisotropy in its light absorption, the hybrid waveguide exhibits much stronger light absorption for TE (in-plane) polarization than TM (out-of-plane) polarization. This enables it to function as a TM-pass optical polarizer.

**Figure 1(d)** shows a microscopic image of the fabricated devices on a silicon-on-insulator (SOI) chip. The device layout was patterned via 248-nm deep ultraviolet lithography followed by inductively coupled plasma etching. A silica upper cladding was deposited onto the
<figure><img src="image_3.png" /><figcaption>FIG. 1. (a) Schematic of GO's atomic structure. (b) Schematic illustration of a waveguide optical polarizer based on a Si waveguide integrated with a monolayer GO film. Inset illustrates the layered structure of GO films fabricated by the self-assembly method. (c) TE and TM mode profiles for the hybrid waveguide in (b). (d) Microscopic image of the fabricated devices on a silicon-on-insulator (SOI) chip coated with a monolayer GO film. (e) Measured Raman spectra of the SOI chip in (d) before and after coating the GO film.</figcaption></figure>

**Figure 1(b)** shows the schematic of a Si nanowire waveguide integrated with a monolayer GO film. The corresponding transverse electric (TE) and transverse magnetic (TM) mode profiles for the hybrid waveguide are shown in **Fig. 1(c)**, which were simulated using a commercial mode solving software (COMSOL Multiphysics). The width and height of the Si waveguide are 400 nm and 220 nm, respectively. Due to the interaction between the evanescent field from the Si waveguide and the 2D GO film with strong anisotropy in its light absorption, the hybrid waveguide exhibits much stronger light absorption for TE (in-plane) polarization than TM (out-of-plane) polarization. This enables it to function as a TM-pass optical polarizer.

**Figure 1(d)** shows a microscopic image of the fabricated devices on a silicon-on-insulator (SOI) chip. The device layout was patterned via 248-nm deep ultraviolet lithography followed by inductively coupled plasma etching. A silica upper cladding was deposited onto the
fabricated Si waveguides. To enable light-GO interaction, lithography and dry etching
processes were employed to open windows on the silica upper cladding to allow the coating of
GO films onto the Si waveguides. We fabricated devices with 5 different lengths (ranging
between ~0.1 mm and ~2.2 mm) for the opened windows, which correspond to different GO
film coating lengths in the hybrid waveguides. The GO films were coated layer-by-layer and
transfer-free with a solution-based self-assembly process.[25, 31] This coating process has
significant advantages over commonly used mechanical transfer methods for coating 2D
materials,[35, 36] achieving large-area conformal coating onto nanostructures, precise film
thickness control, and high film uniformity.[29, 30] As shown in Fig. 1(d), the good morphology
of the coated GO films provides evidence for the high film uniformity achieved by our coating
method.

**Figure 1(e)** shows the measured Raman spectra of the SOI chip in **Fig. 1(d)** before and after coating a monolayer GO film. The GO film had a thickness of ~2 nm, which was characterized by atomic force microscopy measurement. In the Raman spectrum for the GO-coated chip, the presence of the representative *D* (1345 cm⁻¹) and *G* (1590 cm⁻¹) peaks verifies the successful on-chip integration of the GO film.

In **Fig. 2**, we show the results for the measured insertion losses (IL's) of the fabricated
devices for input light with different polarization states. We measured devices with different
GO layer numbers (*N*), GO coating lengths (*L*<sub>GO</sub>), and Si waveguide widths (*W*). For all the
devices, the total length of the Si waveguides was ~3.0 mm. In our measurements, a continuous-
wave (CW) light at ~1550 nm was butt coupled into / out of the devices via lensed fibers. The
fiber-to-chip coupling loss was ~5 dB per facet. For comparison, the input power was kept the
same as *P*<sub>in</sub> = ~0 dBm. Unless otherwise specified, the values of *P*<sub>in</sub> and *IL* in our discussion
fabricated Si waveguides. To enable light-GO interaction, lithography and dry etching
processes were employed to open windows on the silica upper cladding to allow the coating of
GO films onto the Si waveguides. We fabricated devices with 5 different lengths (ranging
between ~0.1 mm and ~2.2 mm) for the opened windows, which correspond to different GO
film coating lengths in the hybrid waveguides. The GO films were coated layer-by-layer and
transfer-free with a solution-based self-assembly process.[25, 31] This coating process has
significant advantages over commonly used mechanical transfer methods for coating 2D
materials,[35, 36] achieving large-area conformal coating onto nanostructures, precise film
thickness control, and high film uniformity.[29, 30] As shown in Fig. 1(d), the good morphology
of the coated GO films provides evidence for the high film uniformity achieved by our coating
method.

**Figure 1(e)** shows the measured Raman spectra of the SOI chip in **Fig. 1(d)** before and after coating a monolayer GO film. The GO film had a thickness of ~2 nm, which was characterized by atomic force microscopy measurement. In the Raman spectrum for the GO-coated chip, the presence of the representative *D* (1345 cm⁻¹) and *G* (1590 cm⁻¹) peaks verifies the successful on-chip integration of the GO film.

In **Fig. 2**, we show the results for the measured insertion losses (IL's) of the fabricated
devices for input light with different polarization states. We measured devices with different
GO layer numbers (*N*), GO coating lengths (*L*<sub>GO</sub>), and Si waveguide widths (*W*). For all the
devices, the total length of the Si waveguides was ~3.0 mm. In our measurements, a continuous-
wave (CW) light at ~1550 nm was butt coupled into / out of the devices via lensed fibers. The
fiber-to-chip coupling loss was ~5 dB per facet. For comparison, the input power was kept the
same as *P*<sub>in</sub> = ~0 dBm. Unless otherwise specified, the values of *P*<sub>in</sub> and *IL* in our discussion
refer to those after excluding the fiber-to-chip coupling loss.

**Figures 2(a-i) and 2(a-ii)** show the measured *IL* versus GO coating length *L*<sub>GO</sub> for TE- and TM-polarized input light, respectively. Here we show the results for the hybrid waveguides with 1–5 layers of GO (i.e., *N* = 1–5). For comparison, all the uncoated Si waveguides had the same waveguide width of *W* = ~400 nm. In our measurements, three duplicate devices were measured, and the data points depict their average values, with the error bars illustrating the variations for different samples. It can be seen that the *IL* increases with *L*<sub>GO</sub> and *N* for both polarizations, with the TE polarization showing a more significant increase than the TM polarization. In **Fig. 2(a-iii)**, we further calculated the *PDL* (dB) by subtracting the TM-polarized *IL* (dB) from the TE-polarized *IL* (dB). As can be seen, the *PDL* increases with *L*<sub>GO</sub> and *N*. For the 5-layer device with *L*<sub>GO</sub> = ~2.2 mm, a maximum *PDL* value of ~17 dB was achieved. In contrast, the uncoated Si waveguide did not show any significant polarization dependent *IL*, with the *PDL* being less than 0.2 dB. The difference in the TM-polarized *IL* values between the uncoated and hybrid waveguides reflects the minimum excess insertion loss induced by the GO film. For the 5-layer device with *L*<sub>GO</sub> = ~2.2 mm, the difference was ~10 dB.

**Figures 2(b-i) and 2(b-ii)** show the measured *IL* versus *W* for TE- and TM-polarized input light, respectively. Here, all the hybrid waveguides had the same *L*<sub>GO</sub> = ~2.2 mm. For both polarizations, the *IL* increases with GO layer number *N*. In contrast to the results in **Figs. 2(a-i)** and **2(a-ii)**, the *IL* decreases as *W* increases, with the TE polarization showing a more significant decrease than the TM polarization. This results in the decrease of *PDL* for an increasing *W* in **Fig. 2(b-iii)**. For the 5-layer device with *W* = ~600 nm, the *PDL* was ~5 dB, which was ~12 dB lower than that of the comparable device with *W* = ~400 nm.
refer to those after excluding the fiber-to-chip coupling loss.

**Figures 2(a-i) and 2(a-ii)** show the measured *IL* versus GO coating length *L*<sub>GO</sub> for TE- and TM-polarized input light, respectively. Here we show the results for the hybrid waveguides with 1–5 layers of GO (i.e., *N* = 1–5). For comparison, all the uncoated Si waveguides had the same waveguide width of *W* = ~400 nm. In our measurements, three duplicate devices were measured, and the data points depict their average values, with the error bars illustrating the variations for different samples. It can be seen that the *IL* increases with *L*<sub>GO</sub> and *N* for both polarizations, with the TE polarization showing a more significant increase than the TM polarization. In **Fig. 2(a-iii)**, we further calculated the *PDL* (dB) by subtracting the TM-polarized *IL* (dB) from the TE-polarized *IL* (dB). As can be seen, the *PDL* increases with *L*<sub>GO</sub> and *N*. For the 5-layer device with *L*<sub>GO</sub> = ~2.2 mm, a maximum *PDL* value of ~17 dB was achieved. In contrast, the uncoated Si waveguide did not show any significant polarization dependent *IL*, with the *PDL* being less than 0.2 dB. The difference in the TM-polarized *IL* values between the uncoated and hybrid waveguides reflects the minimum excess insertion loss induced by the GO film. For the 5-layer device with *L*<sub>GO</sub> = ~2.2 mm, the difference was ~10 dB.

**Figures 2(b-i) and 2(b-ii)** show the measured *IL* versus *W* for TE- and TM-polarized input light, respectively. Here, all the hybrid waveguides had the same *L*<sub>GO</sub> = ~2.2 mm. For both polarizations, the *IL* increases with GO layer number *N*. In contrast to the results in **Figs. 2(a-i)** and **2(a-ii)**, the *IL* decreases as *W* increases, with the TE polarization showing a more significant decrease than the TM polarization. This results in the decrease of *PDL* for an increasing *W* in **Fig. 2(b-iii)**. For the 5-layer device with *W* = ~600 nm, the *PDL* was ~5 dB, which was ~12 dB lower than that of the comparable device with *W* = ~400 nm.
<figure><img src="image_4.png" /></figure>

<figure><img src="image_5.png" /></figure>

<figure><img src="image_6.png" /></figure>

<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /></figure>

<figure><img src="image_9.png" /></figure>

<figure><img src="image_10.png" /></figure>

<figure><img src="image_11.png" /></figure>

<figure><img src="image_12.png" /><figcaption>FIG. 2. (a) Measured (i) TE- and (ii) TM-polarized insertion loss (IL) versus GO coating length $L_{GO}$ for the hybrid waveguides with 1–5 layers of GO. (iii) shows the polarization dependent loss (PDL) calculated from (i) and (iii). (b) Measured (i) TE-, (ii) TM- polarized IL versus Si waveguide width W for the hybrid waveguides with 1–5 layers of GO. (iii) shows the PDL calculated from (i) and (iii). (c) Polar diagrams for the measured IL of devices with different GO layer numbers of (i) $N = 1$, (ii) $N = 3$, and (iii) $N = 5$. The polar angle represents the angle between the input polarization plane and the substrate. In (a) – (c), the input CW power and wavelength were ~0 dBm and ~1550 nm, respectively. In (a) and (b), the data points depict the average of measurements on three duplicate devices and the error bars illustrate the variations among the different devices. In (a), $W = ~400$ nm. In (b), $L_{GO} = ~2.2$ mm. In (c), $L_{GO} = ~2.2$ mm and $W = ~400$ nm.</figcaption></figure>

**Figure 2(c)** shows the polar diagrams for the measured IL of devices with different GO layer numbers (i.e., $N = 1, 3$, and $5$). Except for the GO layer number, the other device parameters were kept the same (i.e., $W = ~400$ nm and $L_{GO} = ~2.2$ mm). In the polar diagrams, the variations in the IL values across various polarization angles further confirm the polarization selection capability for the hybrid waveguides. Compared to the 5-layer device that achieved a
<figure><img src="image_4.png" /></figure>

<figure><img src="image_5.png" /></figure>

<figure><img src="image_6.png" /></figure>

<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /></figure>

<figure><img src="image_9.png" /></figure>

<figure><img src="image_10.png" /></figure>

<figure><img src="image_11.png" /></figure>

<figure><img src="image_12.png" /><figcaption>FIG. 2. (a) Measured (i) TE- and (ii) TM-polarized insertion loss (IL) versus GO coating length $L_{GO}$ for the hybrid waveguides with 1–5 layers of GO. (iii) shows the polarization dependent loss (PDL) calculated from (i) and (iii). (b) Measured (i) TE-, (ii) TM- polarized IL versus Si waveguide width W for the hybrid waveguides with 1–5 layers of GO. (iii) shows the PDL calculated from (i) and (iii). (c) Polar diagrams for the measured IL of devices with different GO layer numbers of (i) $N = 1$, (ii) $N = 3$, and (iii) $N = 5$. The polar angle represents the angle between the input polarization plane and the substrate. In (a) – (c), the input CW power and wavelength were ~0 dBm and ~1550 nm, respectively. In (a) and (b), the data points depict the average of measurements on three duplicate devices and the error bars illustrate the variations among the different devices. In (a), $W = ~400$ nm. In (b), $L_{GO} = ~2.2$ mm. In (c), $L_{GO} = ~2.2$ mm and $W = ~400$ nm.</figcaption></figure>

**Figure 2(c)** shows the polar diagrams for the measured IL of devices with different GO layer numbers (i.e., $N = 1, 3$, and $5$). Except for the GO layer number, the other device parameters were kept the same (i.e., $W = ~400$ nm and $L_{GO} = ~2.2$ mm). In the polar diagrams, the variations in the IL values across various polarization angles further confirm the polarization selection capability for the hybrid waveguides. Compared to the 5-layer device that achieved a
PDL of ~17 dB, the 1-layer and 3-layer devices achieved lower PDL values of ~5 dB and ~9
dB, respectively.

**Figure 3a** shows the measured PDL versus wavelength of the input CW light. In **Fig. 3(a-i)**, we show the results for the hybrid waveguides with 1 – 5 layers of GO (i.e., *N* = 1 – 5) and all of them had the same *L*<sub>GO</sub> = ~2.2 mm and *W* = ~400 nm. In **Fig. 3(a-ii)**, we show the results for the hybrid waveguides with different *L*<sub>GO</sub> but the same *N* = 5 and *W* = ~400 nm. For all the devices in **Fig. 3a**, the PDL shows a very small variation that was less than 1 dB within the measured wavelength range of ~1500 – 1600 nm. This reflects the broad operation bandwidth for these waveguide polarizers. We note that there was a slight increase in the PDL as the wavelength increased, which can be attributed to a minor change in GO’s mode overlap induced by dispersion. In our measurements, the wavelength tuning range was limited by the employed tunable CW laser. The light absorption bandwidth for GO is in fact quite broad, which covers infrared wavelengths and extends into the visible and terahertz (THz) ranges.[29, 37] Such broadband response enables a much broader operation bandwidth (potentially spanning several hundreds of nanometers, as we demonstrated in Ref. [25]) than that demonstrated here. This represents a significant advantage of 2D-material-based polarizers, which is usually challenging to achieve for integrated photonic devices based on only bulk materials.[2, 38]
PDL of ~17 dB, the 1-layer and 3-layer devices achieved lower PDL values of ~5 dB and ~9
dB, respectively.

**Figure 3a** shows the measured PDL versus wavelength of the input CW light. In **Fig. 3(a-i)**, we show the results for the hybrid waveguides with 1 – 5 layers of GO (i.e., *N* = 1 – 5) and all of them had the same *L*<sub>GO</sub> = ~2.2 mm and *W* = ~400 nm. In **Fig. 3(a-ii)**, we show the results for the hybrid waveguides with different *L*<sub>GO</sub> but the same *N* = 5 and *W* = ~400 nm. For all the devices in **Fig. 3a**, the PDL shows a very small variation that was less than 1 dB within the measured wavelength range of ~1500 – 1600 nm. This reflects the broad operation bandwidth for these waveguide polarizers. We note that there was a slight increase in the PDL as the wavelength increased, which can be attributed to a minor change in GO’s mode overlap induced by dispersion. In our measurements, the wavelength tuning range was limited by the employed tunable CW laser. The light absorption bandwidth for GO is in fact quite broad, which covers infrared wavelengths and extends into the visible and terahertz (THz) ranges.[29, 37] Such broadband response enables a much broader operation bandwidth (potentially spanning several hundreds of nanometers, as we demonstrated in Ref. [25]) than that demonstrated here. This represents a significant advantage of 2D-material-based polarizers, which is usually challenging to achieve for integrated photonic devices based on only bulk materials.[2, 38]
<figure><img src="image_13.png" /></figure>

<figure><img src="image_14.png" /></figure>

<figure><img src="image_15.png" /></figure>

<figure><img src="image_16.png" /></figure>

<figure><img src="image_17.png" /></figure>

<figure><img src="image_18.png" /><figcaption>FIG. 3. (a) Measured PDL versus wavelength of input CW light for (i) devices with different GO layer numbers ($N$) but the same GO coating length ($L_{GO}$) of ~2.2 mm and (ii) devices with different $L_{GO}$ but the same $N = 5$. (b) (i) Measured TE and TM polarized IL versus input power ($P_{in}$) for devices with different $N = 1, 3,$ and 5 but the same $L_{GO} = ~2.2$ mm. (ii) shows the PDL calculated from (i). (c) (i) Measured TE and TM polarized IL versus $P_{in}$ for devices with different $L_{GO} = 0.2, 1.0,$ and 2.2 mm but the same $N = 5$. (ii) shows the PDL calculated from (i). In (a) – (c), $W = ~400$ nm. In (a), $P_{in} = ~0$ dBm. In (b) and (c), the input CW wavelength was ~1550 nm.</figcaption></figure>

**Figure 3(b-i)** shows the measured *IL* versus input power *P*<sub>in</sub> for the hybrid waveguides with 1, 3, and 5 layers of GO. Here all the devices had the same *L*<sub>GO</sub> = ~2.2 mm and *W* = ~400 nm. As *P*<sub>in</sub> increases, the *IL* increases for both polarizations, with the TE polarization showing a more significant increase than the TM polarization. The increased *IL* was induced by the photo-thermal reduction of GO at high light powers, where reduced GO exhibited stronger light absorption than unreduced GO.[30, 39] Another interesting feature for the reduction of GO induced by photo-thermal effects is its reversibility within a certain power range.[39, 40] This originates from the instability of photo-thermally reduced GO, which can readily return to the unreduced state after cooling in oxygen containing atmosphere (e.g., after tuning off the optical input). Since the hybrid waveguides exhibited stronger absorption for TE-polarized light, the reduction of GO occurred more readily for TE polarization, resulting in a more significant change in the corresponding *IL* in Fig. 3(b-i). We also note that the 5-layer device showed more
<figure><img src="image_13.png" /></figure>

<figure><img src="image_14.png" /></figure>

<figure><img src="image_15.png" /></figure>

<figure><img src="image_16.png" /></figure>

<figure><img src="image_17.png" /></figure>

<figure><img src="image_18.png" /><figcaption>FIG. 3. (a) Measured PDL versus wavelength of input CW light for (i) devices with different GO layer numbers ($N$) but the same GO coating length ($L_{GO}$) of ~2.2 mm and (ii) devices with different $L_{GO}$ but the same $N = 5$. (b) (i) Measured TE and TM polarized IL versus input power ($P_{in}$) for devices with different $N = 1, 3,$ and 5 but the same $L_{GO} = ~2.2$ mm. (ii) shows the PDL calculated from (i). (c) (i) Measured TE and TM polarized IL versus $P_{in}$ for devices with different $L_{GO} = 0.2, 1.0,$ and 2.2 mm but the same $N = 5$. (ii) shows the PDL calculated from (i). In (a) – (c), $W = ~400$ nm. In (a), $P_{in} = ~0$ dBm. In (b) and (c), the input CW wavelength was ~1550 nm.</figcaption></figure>

**Figure 3(b-i)** shows the measured *IL* versus input power *P*<sub>in</sub> for the hybrid waveguides with 1, 3, and 5 layers of GO. Here all the devices had the same *L*<sub>GO</sub> = ~2.2 mm and *W* = ~400 nm. As *P*<sub>in</sub> increases, the *IL* increases for both polarizations, with the TE polarization showing a more significant increase than the TM polarization. The increased *IL* was induced by the photo-thermal reduction of GO at high light powers, where reduced GO exhibited stronger light absorption than unreduced GO.[30, 39] Another interesting feature for the reduction of GO induced by photo-thermal effects is its reversibility within a certain power range.[39, 40] This originates from the instability of photo-thermally reduced GO, which can readily return to the unreduced state after cooling in oxygen containing atmosphere (e.g., after tuning off the optical input). Since the hybrid waveguides exhibited stronger absorption for TE-polarized light, the reduction of GO occurred more readily for TE polarization, resulting in a more significant change in the corresponding *IL* in **Fig. 3(b-i)**. We also note that the 5-layer device showed more
significant changes in the *IL* as compared to the 3-layer and 1-layer devices, which reflects the fact that there were more significant photo-thermal effects in thicker GO films. In **Fig. 3(b-ii)**, we show the calculated *PDL* versus *P*<sub>in</sub>, where the *PDL* increases for an increasing *P*<sub>in</sub>. This indicates that the polarization selectivity was further improved by increasing the input power. At *P*<sub>in</sub> = ~15 dBm, the *PDL* for the 5-layer device was ~25 dB, representing an ~8-dB improvement relative to the *PDL* at *P*<sub>in</sub> = ~0 dBm.

**Figure 3(c-i)** shows the measured *IL* versus *P*<sub>in</sub> for the hybrid waveguides with three different *L*<sub>GO</sub> but the same *N* = 5 and *W* = ~400 nm. The extracted *PDL* versus *P*<sub>in</sub> is shown in **Fig. 3(c-ii)**. For all the devices, the *PDL* starts to increase at almost the same power threshold of *P*<sub>in</sub> = ~6 dB. After that, the devices with *L*<sub>GO</sub> = ~1.0 mm and ~2.2 mm exhibit a similar rate of increase, whereas the rate for the device with *L*<sub>GO</sub> = ~0.2 mm gradually decreases. This reflects an interesting fact that the reduction of GO induced by the photo-thermal effects was non-uniform along the waveguide. It first occurred at the start of the GO section near the input port and became weaker in tandem with the attenuation of the light power along the waveguide.

Based on the results in Figs. 2 and 3, we further analyze the properties of 2D GO films by fitting the experimental results with theoretical simulations. **Figure 4(a-i)** shows the propagation losses (*PL*'s) of the hybrid waveguides versus GO layer number *N* for both polarizations, which were extracted from the measured *IL*'s in Figs. 2(a-i) and 2(a-ii). **Figure 4(a-ii)** shows the extinction coefficients (*k*'s) of 2D GO films obtained by fitting the *PL*'s in Fig. 4(a-i) with optical mode simulations, and the ratios of TE- to TM-polarized *k* values are further plotted in Fig. 4(a-iii). For all different *N*, the GO films exhibit much larger *k* values for TE polarization than TM polarization in Fig. 4(a-ii), highlighting the high anisotropy in their light absorption. For both polarizations, there is a slight increase in *k* as *N* increases. This can
significant changes in the *IL* as compared to the 3-layer and 1-layer devices, which reflects the fact that there were more significant photo-thermal effects in thicker GO films. In **Fig. 3(b-ii)**, we show the calculated *PDL* versus *P*<sub>in</sub>, where the *PDL* increases for an increasing *P*<sub>in</sub>. This indicates that the polarization selectivity was further improved by increasing the input power. At *P*<sub>in</sub> = ~15 dBm, the *PDL* for the 5-layer device was ~25 dB, representing an ~8-dB improvement relative to the *PDL* at *P*<sub>in</sub> = ~0 dBm.

**Figure 3(c-i)** shows the measured *IL* versus *P*<sub>in</sub> for the hybrid waveguides with three different *L*<sub>GO</sub> but the same *N* = 5 and *W* = ~400 nm. The extracted *PDL* versus *P*<sub>in</sub> is shown in **Fig. 3(c-ii)**. For all the devices, the *PDL* starts to increase at almost the same power threshold of *P*<sub>in</sub> = ~6 dB. After that, the devices with *L*<sub>GO</sub> = ~1.0 mm and ~2.2 mm exhibit a similar rate of increase, whereas the rate for the device with *L*<sub>GO</sub> = ~0.2 mm gradually decreases. This reflects an interesting fact that the reduction of GO induced by the photo-thermal effects was non-uniform along the waveguide. It first occurred at the start of the GO section near the input port and became weaker in tandem with the attenuation of the light power along the waveguide.

Based on the results in Figs. 2 and 3, we further analyze the properties of 2D GO films by fitting the experimental results with theoretical simulations. **Figure 4(a-i)** shows the propagation losses (*PL*'s) of the hybrid waveguides versus GO layer number *N* for both polarizations, which were extracted from the measured *IL*'s in Figs. 2(a-i) and 2(a-ii). **Figure 4(a-ii)** shows the extinction coefficients (*k*'s) of 2D GO films obtained by fitting the *PL*'s in **Fig. 4(a-i)** with optical mode simulations, and the ratios of TE- to TM-polarized *k* values are further plotted in **Fig. 4(a-iii)**. For all different *N*, the GO films exhibit much larger *k* values for TE polarization than TM polarization in **Fig. 4(a-ii)**, highlighting the high anisotropy in their light absorption. For both polarizations, there is a slight increase in *k* as *N* increases. This can
possibly be attributed to more significant scattering loss in thicker GO films, which can be
induced by increased film unevenness and imperfect contact between adjacent layers. It is also
interesting to note that in **Fig. 4(a-iii)** the ratio of the *k* values remains relatively consistent
without any significant variations.

<figure><img src="image_19.png" /><figcaption>FIG. 4. (a-i) TE- and TM-polarized waveguide propagation loss (PL) versus GO layer number (N) for the hybrid waveguides with 1–5 layers of GO. (a-ii) Extinction coefficients (k's) of 2D GO films obtained by fitting the results in (a-i) with optical mode simulations. (a-iii) Ratios of k values for TE and TM polarizations (k<sub>TE</sub> / k<sub>TM</sub>) extracted from (a-ii). (b) Measured (Exp.) and simulated (Sim.) PDL versus Si waveguide width (W) for the hybrid waveguides with 5 layers of GO. The simulated PDL values were obtained by using the same k value for both TE and TM polarizations. (c-i) Measured (Exp.) and simulated (Sim.) PDL versus N. (c-ii) Fractional contributions (η's) to the overall PDL from polarization-dependent mode overlap and material loss anisotropy, which were extracted from (c-i). (d-i) TE- and TM-polarized PL versus input power (P<sub>in</sub>) for the hybrid waveguide with 5 layers of GO. (d-ii) k's of 2D GO films obtained by fitting the results in (d-i) with optical mode simulations. (d-iii) k<sub>TE</sub> / k<sub>TM</sub> extracted from (d-ii). In (a) – (d), the GO coating length L<sub>GO</sub> = ~2.2 mm. In (a) – (c), P<sub>in</sub> = ~0 dBm. In (a), (c), and (d), W = ~400 nm.</figcaption></figure>
possibly be attributed to more significant scattering loss in thicker GO films, which can be
induced by increased film unevenness and imperfect contact between adjacent layers. It is also
interesting to note that in **Fig. 4(a-iii)** the ratio of the *k* values remains relatively consistent
without any significant variations.

<figure><img src="image_19.png" /><figcaption>FIG. 4. (a-i) TE- and TM-polarized waveguide propagation loss (PL) versus GO layer number (N) for the hybrid waveguides with 1–5 layers of GO. (a-ii) Extinction coefficients (k's) of 2D GO films obtained by fitting the results in (a-i) with optical mode simulations. (a-iii) Ratios of k values for TE and TM polarizations (k<sub>TE</sub> / k<sub>TM</sub>) extracted from (a-ii). (b) Measured (Exp.) and simulated (Sim.) PDL versus Si waveguide width (W) for the hybrid waveguides with 5 layers of GO. The simulated PDL values were obtained by using the same k value for both TE and TM polarizations. (c-i) Measured (Exp.) and simulated (Sim.) PDL versus N. (c-ii) Fractional contributions (η's) to the overall PDL from polarization-dependent mode overlap and material loss anisotropy, which were extracted from (c-i). (d-i) TE- and TM-polarized PL versus input power (P<sub>in</sub>) for the hybrid waveguide with 5 layers of GO. (d-ii) k's of 2D GO films obtained by fitting the results in (d-i) with optical mode simulations. (d-iii) k<sub>TE</sub> / k<sub>TM</sub> extracted from (d-ii). In (a) – (d), the GO coating length L<sub>GO</sub> = ~2.2 mm. In (a) – (c), P<sub>in</sub> = ~0 dBm. In (a), (c), and (d), W = ~400 nm.</figcaption></figure>
In Fig. 4b, we compare the measured PDL values with those obtained from optical mode simulations. In our simulations, we assumed that the GO films were isotropic with the same *k* value (i.e., *k*<sub>TE</sub> for *N* = 5 in Fig. 4(a-ii)) for both TE and TM polarizations. As a result, the simulated PDL values represent the polarization selectivity enabled by the polarization-dependent GO mode overlap, and the difference between the measured and simulated PDL values reflects the extra polarization selectivity provided by the loss anisotropy of GO films. The simulated PDL values are negative when *W* > 400 nm. This is because the polarization-dependent GO mode overlap induces a higher loss for TM polarization. Despite this, the net PDL values remain positive, indicating that the material loss anisotropy compensates for the negative PDL induced by GO mode overlap.

Similar to that in **Fig. 4b**, in **Fig. 4(c-i)** we show the measured and simulated PDL values for the devices with different *N* but the same *W* ~400 nm. Unlike that in **Fig. 4b**, both the measured and simulated PDL's show positive values for all different *N*. This suggests that the polarization-dependent GO mode overlap also contributes to the overall PDL. In **Fig. 4(c-ii)**, we further calculated the fractional contributions to the overall PDL from the polarization-dependent mode overlap and the material loss anisotropy (where the sum of the two fractions equals to 1). As can be seen, the contribution from the material loss anisotropy, which accounts for more than 70% for all different GO layer numbers, dominates the overall PDL. This further highlights the significance of the anisotropic 2D GO films in facilitating the functionality of the polarizer.

**Figure 4(d-i)** shows the PL's of the hybrid waveguides versus input CW power $P_{in}$ for both polarizations, which were extracted from the measured IL's in **Fig. 3b**. **Figure 4(d-ii)** shows the *k* values of 2D GO films obtained by fitting the PL's in **Fig. 4(d-i)** with optical mode
In Fig. 4b, we compare the measured PDL values with those obtained from optical mode simulations. In our simulations, we assumed that the GO films were isotropic with the same *k* value (i.e., *k*<sub>TE</sub> for *N* = 5 in Fig. 4(a-ii)) for both TE and TM polarizations. As a result, the simulated PDL values represent the polarization selectivity enabled by the polarization-dependent GO mode overlap, and the difference between the measured and simulated PDL values reflects the extra polarization selectivity provided by the loss anisotropy of GO films. The simulated PDL values are negative when *W* > 400 nm. This is because the polarization-dependent GO mode overlap induces a higher loss for TM polarization. Despite this, the net PDL values remain positive, indicating that the material loss anisotropy compensates for the negative PDL induced by GO mode overlap.

Similar to that in **Fig. 4b**, in **Fig. 4(c-i)** we show the measured and simulated PDL values for the devices with different *N* but the same *W* ~400 nm. Unlike that in **Fig. 4b**, both the measured and simulated PDL's show positive values for all different *N*. This suggests that the polarization-dependent GO mode overlap also contributes to the overall PDL. In **Fig. 4(c-ii)**, we further calculated the fractional contributions to the overall PDL from the polarization-dependent mode overlap and the material loss anisotropy (where the sum of the two fractions equals to 1). As can be seen, the contribution from the material loss anisotropy, which accounts for more than 70% for all different GO layer numbers, dominates the overall PDL. This further highlights the significance of the anisotropic 2D GO films in facilitating the functionality of the polarizer.

**Figure 4(d-i)** shows the *PL*'s of the hybrid waveguides versus input CW power $P_{in}$ for both polarizations, which were extracted from the measured *IL*'s in **Fig. 3b**. **Figure 4(d-ii)** shows the *k* values of 2D GO films obtained by fitting the *PL*'s in **Fig. 4(d-i)** with optical mode
simulations, and Fig. 4(d-iii) shows the ratios of the TE- to TM-polarized *k* values in Fig. 4(d-ii). In Fig. 4(d-ii), *k* increases with *P*<sub>in</sub> for both polarizations, with the TE polarization showing a more significant increase than the TM polarization. In Fig. 4(d-iii), the ratio between the *k* values slightly increases with *P*<sub>in</sub>, which is also resulting from the more significant photo-thermal effects in GO films induced by stronger absorption of TE-polarized light.

Except for waveguide optical polarizers, we also integrated 2D GO films onto Si MRRs to implement polarization-selective MRRs. **Figure 5(a)** shows the device schematic, and **Figure 5(b)** shows a microscopic image of the fabricated device with a monolayer GO film. The MRRs were fabricated together with the waveguides in **Fig. 1(d)** via the same processes. The rings and the bus waveguides had the same width of $W \sim 400$ nm. The radius of the MRRs was $\sim 20$ µm, and the length of the opened windows on the MRRs was $\sim 10$ µm.

By scanning the wavelength of a CW light coupled into the bus waveguides, we measured the TE- and TM-polarized transmission spectra of the MRRs. **Figure 5(c)** shows the measured spectra for the hybrid MRRs with 1 and 2 layers of GO, together with those for the uncoated MRR for comparison. For all the measured spectra, the input CW power remained constant at $P_{in} \sim 10$ dBm. **Figure 5(d)** shows the extinction ratios (ER's) of these MRRs extracted from **Fig. 5(c)**. For the uncoated MRR, the ERs for TE and TM polarizations were $\sim 33$ dB and $\sim 32$ dB, respectively. In contrast, the ERs decreased to $\sim 16$ dB and $\sim 26$ dB for the 1-layer device, and $\sim 11$ dB and $\sim 19$ dB for the 2-layer device. **Figure 5(e)** shows the polarization extinction ratio (PER) calculated from **Fig. 5(d)**, which is defined as the absolute difference between the ER's of the TE- and TM-polarized resonances. As can be seen, the uncoated MRR exhibited negligible polarization selectivity, with its PER being less than $\sim 1$ dB. In contrast, the hybrid devices with 1 and 2 layers of GO exhibited PER values of $\sim 10$ dB and $\sim 8$ dB, respectively,
simulations, and Fig. 4(d-iii) shows the ratios of the TE- to TM-polarized *k* values in Fig. 4(d-ii). In Fig. 4(d-ii), *k* increases with *P*<sub>in</sub> for both polarizations, with the TE polarization showing a more significant increase than the TM polarization. In Fig. 4(d-iii), the ratio between the *k* values slightly increases with *P*<sub>in</sub>, which is also resulting from the more significant photo-thermal effects in GO films induced by stronger absorption of TE-polarized light.

Except for waveguide optical polarizers, we also integrated 2D GO films onto Si MRRs to implement polarization-selective MRRs. **Figure 5(a)** shows the device schematic, and **Figure 5(b)** shows a microscopic image of the fabricated device with a monolayer GO film. The MRRs were fabricated together with the waveguides in **Fig. 1(d)** via the same processes. The rings and the bus waveguides had the same width of $W \sim 400$ nm. The radius of the MRRs was $\sim 20$ µm, and the length of the opened windows on the MRRs was $\sim 10$ µm.

By scanning the wavelength of a CW light coupled into the bus waveguides, we measured the TE- and TM-polarized transmission spectra of the MRRs. **Figure 5(c)** shows the measured spectra for the hybrid MRRs with 1 and 2 layers of GO, together with those for the uncoated MRR for comparison. For all the measured spectra, the input CW power remained constant at $P_{in} \sim 10$ dBm. **Figure 5(d)** shows the extinction ratios (ER's) of these MRRs extracted from **Fig. 5(c)**. For the uncoated MRR, the ERs for TE and TM polarizations were $\sim 33$ dB and $\sim 32$ dB, respectively. In contrast, the ERs decreased to $\sim 16$ dB and $\sim 26$ dB for the 1-layer device, and $\sim 11$ dB and $\sim 19$ dB for the 2-layer device. **Figure 5(e)** shows the polarization extinction ratio (PER) calculated from **Fig. 5(d)**, which is defined as the absolute difference between the ER's of the TE- and TM-polarized resonances. As can be seen, the uncoated MRR exhibited negligible polarization selectivity, with its PER being less than $\sim 1$ dB. In contrast, the hybrid devices with 1 and 2 layers of GO exhibited PER values of $\sim 10$ dB and $\sim 8$ dB, respectively,
highlighting their high polarization selectivity. Compared to the device with 2 layers of GO,
the device with 1 layer of GO exhibited a higher *PER*. This is mainly induced by a more
significant decrease in the TM-polarized *ER* for the device with a thicker GO film.

<figure><img src="image_20.png" /><figcaption>FIG. 5. (a) Schematic illustration of a GO-coated Si microring resonator (MRR) as a polarization-selective MRR. (b) Microscopic image of a fabricated Si MRR coated with a monolayer GO film. (c) Measured (i) TE- and (ii) TM-polarized transmission spectra of the hybrid MRRs with 1 and 2 layers of GO (N = 1, 2). The corresponding results for the uncoated MRR (N = 0) are also shown for comparison. (d) Extinction ratios (ER's) for the MRRs extracted from (c). (e) Polarization extinction ratios (PER's) extracted from (d). In (c) – (e), the CW input power was P_in = ~10 dBm.</figcaption></figure>

In Fig. 6, we characterize the power-dependent response for the polarization-selective
MRR. We employed two CW inputs in our measurements. On CW beam provided a pump into
one of the MRR's tuned to a resonance. Its wavelength was adjusted near the resonance until a
highlighting their high polarization selectivity. Compared to the device with 2 layers of GO,
the device with 1 layer of GO exhibited a higher *PER*. This is mainly induced by a more
significant decrease in the TM-polarized *ER* for the device with a thicker GO film.

<figure><img src="image_20.png" /><figcaption>FIG. 5. (a) Schematic illustration of a GO-coated Si microring resonator (MRR) as a polarization-selective MRR. (b) Microscopic image of a fabricated Si MRR coated with a monolayer GO film. (c) Measured (i) TE- and (ii) TM-polarized transmission spectra of the hybrid MRRs with 1 and 2 layers of GO (N = 1, 2). The corresponding results for the uncoated MRR (N = 0) are also shown for comparison. (d) Extinction ratios (*ER*)'s for the MRRs extracted from (c). (e) Polarization extinction ratios (*PER*)'s extracted from (d). In (c) – (e), the CW input power was P_in = ~10 dBm.</figcaption></figure>

In Fig. 6, we characterize the power-dependent response for the polarization-selective
MRR. We employed two CW inputs in our measurements. On CW beam provided a pump into
one of the MRR's tuned to a resonance. Its wavelength was adjusted near the resonance until a
thermal equilibrium state was reached. Next, a second lower CW power beam at -10 dBm was used to probe the MRR's transmission spectra. In contrast to directly using a high-power CW pump to scan the spectra, the probe minimized any resonance lineshape asymmetry due to optical bistability, [41, 42] thus enabling more precise characterization of the ERs.

<figure><img src="image_21.png" /><figcaption>FIG. 6. (a) TE- and TM-polarized *ER* versus input power (*P*<sub>in</sub>) for the hybrid MRR with 1 layer of GO (N = 1). (b) *PER* extracted from (a). (c) Fit *k*′s obtained from the MRR experiment and the waveguide (WG) experiment. (d) Ratios of *k* values for TE and TM polarizations (*k*<sub>TE</sub> / *k*<sub>TM</sub>) extracted from (c).</figcaption></figure>

In Fig. 6(a), we plot TE- and TM-polarized *ER*’s versus input pump power *P*<sub>in</sub> for the hybrid MRR with 1 layer of GO. Fig. 6(b) shows the *PER* calculated from Fig. 6(a). For TE polarization in Fig. 6(a), the *ER* remains constant at ~17 dB when *P*<sub>in</sub> ≤ ~0 dBm. When *P*<sub>in</sub> > ~0 dBm, there is an obvious decrease in the *ER* resulting from an increased loss induced by photo-thermal reduction of GO. For TM polarization, the *ER* remains constant at ~26 dB when *P*<sub>in</sub> ≤ 4 dBm, followed by a decrease when *P*<sub>in</sub> > 4 dBm. Compared to TE polarization, TM polarization exhibits a higher power threshold at which the *ER* starts to decrease. This further confirms the relatively weak photo-thermal effects for TM polarization. In Fig. 6(b), the higher power threshold for TM polarization also leads to a slight increase in the *PER* when ~0 dBm <
thermal equilibrium state was reached. Next, a second lower CW power beam at -10 dBm was used to probe the MRR's transmission spectra. In contrast to directly using a high-power CW pump to scan the spectra, the probe minimized any resonance lineshape asymmetry due to optical bistability, [41, 42] thus enabling more precise characterization of the ERs.

<figure><img src="image_21.png" /><figcaption>FIG. 6. (a) TE- and TM-polarized *ER* versus input power (*P*<sub>in</sub>) for the hybrid MRR with 1 layer of GO (N = 1). (b) *PER* extracted from (a). (c) Fit *k*′s obtained from the MRR experiment and the waveguide (WG) experiment. (d) Ratios of *k* values for TE and TM polarizations (*k*<sub>TE</sub> / *k*<sub>TM</sub>) extracted from (c).</figcaption></figure>

In Fig. 6(a), we plot TE- and TM-polarized *ER*’s versus input pump power *P*<sub>in</sub> for the hybrid MRR with 1 layer of GO. Fig. 6(b) shows the *PER* calculated from Fig. 6(a). For TE polarization in Fig. 6(a), the *ER* remains constant at ~17 dB when *P*<sub>in</sub> ≤ ~0 dBm. When *P*<sub>in</sub> > ~0 dBm, there is an obvious decrease in the *ER* resulting from an increased loss induced by photo-thermal reduction of GO. For TM polarization, the *ER* remains constant at ~26 dB when *P*<sub>in</sub> ≤ 4 dBm, followed by a decrease when *P*<sub>in</sub> > 4 dBm. Compared to TE polarization, TM polarization exhibits a higher power threshold at which the *ER* starts to decrease. This further confirms the relatively weak photo-thermal effects for TM polarization. In Fig. 6(b), the higher power threshold for TM polarization also leads to a slight increase in the *PER* when ~0 dBm <
$P_{in} < 4$ dBm. We also note that the PER slightly decreases when $P_{in} > 4$ dBm. This is mainly induced by a more dramatic decrease in the ER for TM polarization, which has a higher value (in dB) compared to TE polarization. It is also worth mentioning that the results in Fig. 6 were measured at one of the MRRs' resonance wavelengths near 1550 nm. Similar phenomena were also observed at other resonance wavelengths within the maximum tuning range of our CW laser (i.e., 1500–1600 nm).

By using the scattering matrix method[43-51] to fit the measured transmission spectra, we obtained the PL's of the GO-coated segment in the hybrid MRR. The k's of 2D GO films were further extracted from the obtained PL's using the same method as in Figs. 4(a). Figure 6(c) shows the k's of 2D GO films versus $P_{in}$, and Fig. 6(b) shows the ratios of the TE- to TM-polarized k values calculated from Fig. 6(c). For comparison, we also show the corresponding results obtained from the waveguide experiment in Fig. 4(d). In Fig. 6(c), the k values obtained from the MRR experiment match closely with those obtained from the waveguide experiment, reflecting the consistency of our GO film fabrication process. As the input power increases, the k obtained from the MRR experiment exhibits a more significant increase, indicating that there was more significant photo-thermal reduction of GO in the hybrid MRR due to the resonant enhancement effect. When $P_{in} \le 0$ dBm, the ratio in Fig. 6(d) remains nearly constant at ~5.3, which is consistent with that in Fig. 4(a-iii). For $P_{in} > 0$ dBm, the ratio increases with $P_{in}$, achieving a maximum value of ~6.9 at $P_{in} = 8$ dBm. In contrast, the ratio obtained from the hybrid waveguide was still ~5.3 at the same input power.

In summary, waveguide and MRR polarizers are demonstrated by integrating 2D GO films onto Si photonic devices. We fabricate hybrid devices with precise control over the thicknesses and lengths of GO films and perform detailed measurements with them. By optimizing the GO
$P_{in} < 4$ dBm. We also note that the PER slightly decreases when $P_{in} > 4$ dBm. This is mainly induced by a more dramatic decrease in the ER for TM polarization, which has a higher value (in dB) compared to TE polarization. It is also worth mentioning that the results in Fig. 6 were measured at one of the MRRs' resonance wavelengths near 1550 nm. Similar phenomena were also observed at other resonance wavelengths within the maximum tuning range of our CW laser (i.e., 1500–1600 nm).

By using the scattering matrix method[43-51] to fit the measured transmission spectra, we obtained the PL's of the GO-coated segment in the hybrid MRR. The k's of 2D GO films were further extracted from the obtained PL's using the same method as in Figs. 4(a). Figure 6(c) shows the k's of 2D GO films versus $P_{in}$, and Fig. 6(b) shows the ratios of the TE- to TM-polarized k values calculated from Fig. 6(c). For comparison, we also show the corresponding results obtained from the waveguide experiment in Fig. 4(d). In Fig. 6(c), the k values obtained from the MRR experiment match closely with those obtained from the waveguide experiment, reflecting the consistency of our GO film fabrication process. As the input power increases, the k obtained from the MRR experiment exhibits a more significant increase, indicating that there was more significant photo-thermal reduction of GO in the hybrid MRR due to the resonant enhancement effect. When $P_{in} \le 0$ dBm, the ratio in Fig. 6(d) remains nearly constant at ~5.3, which is consistent with that in Fig. 4(a-iii). For $P_{in} > 0$ dBm, the ratio increases with $P_{in}$, achieving a maximum value of ~6.9 at $P_{in} = 8$ dBm. In contrast, the ratio obtained from the hybrid waveguide was still ~5.3 at the same input power.

In summary, waveguide and MRR polarizers are demonstrated by integrating 2D GO films onto Si photonic devices. We fabricate hybrid devices with precise control over the thicknesses and lengths of GO films and perform detailed measurements with them. By optimizing the GO
film thicknesses, lengths, and Si waveguide widths, up to ~17-dB *PDL* and ~10-dB *PER* are achieved for the waveguide and MRR polarizers, respectively. The dependence of the polarizers' response on the wavelength and power of input light is also characterized, showing a broad operation bandwidth over ~100 nm as well as polarization selectivity improvement enabled by photo-thermal changes in GO. Finally, we find that the anisotropy in the loss of GO films dominates the polarization selectivity of these polarizers by fitting the experimental results with theoretical simulations. Our study provides an attractive approach for implementing high-performance optical polarizers by integrating 2D GO films onto Si photonic devices and complements the recent advances made in GO coated nanophotonic devices for linear and nonlinear optics. [52-107] Our study also provides an attractive application for integrated nonlinear devices in general [108-191]

## AUTHOR DECLARATIONS

### Conflict of Interest

The authors have no conflicts to disclose.

### References

[1] Y. Yan, G. Xie, M. P. J. Lavery, H. Huang, N. Ahmed, C. Bao, Y. Ren, Y. Cao, L. Li, Z. Zhao, A. F. Molisch, M. Tur, M. J. Padgett, and A. E. Willner, "High-capacity millimetre-wave communications with orbital angular momentum multiplexing," *Nature Communications*, vol. 5, no. 1, pp. 4876, 2014/09/16, 2014.

[2] D. Dai, L. Liu, S. Gao, D.-X. Xu, and S. He, "Polarization management for silicon photonic integrated circuits," *Laser & Photonics Reviews*, vol. 7, no. 3, pp. 303-328, 2013/05/01, 2013.

[3] J. Chu, K. Zhao, Q. Zhang, and T. Wang, "Construction and performance test of a novel polarization sensor for navigation," *Sensors and Actuators A: Physical*, vol. 148, no. 1, pp. 75-82, 2008/11/04/, 2008.

[4] V. Thilak, D. G. Voelz, and C. D. Creusere, "Polarization-based index of refraction and reflection angle estimation for remote sensing applications," *Applied Optics*, vol. 46, no. 30, pp. 7527-7536, 2007/10/20, 2007.

[5] C.-T. Lee, H.-Y. Lin, and C.-H. Tsai, "Designs of broadband and wide-view patterned polarizers for stereoscopic 3D displays," *Optics Express*, vol. 18, no. 26, pp. 27079-27094, 2010/12/20, 2010.

[6] S. H. Kim, J.-D. Park, and K.-D. Lee, "Fabrication of a nano-wire grid polarizer for brightness
film thicknesses, lengths, and Si waveguide widths, up to ~17-dB *PDL* and ~10-dB *PER* are achieved for the waveguide and MRR polarizers, respectively. The dependence of the polarizers' response on the wavelength and power of input light is also characterized, showing a broad operation bandwidth over ~100 nm as well as polarization selectivity improvement enabled by photo-thermal changes in GO. Finally, we find that the anisotropy in the loss of GO films dominates the polarization selectivity of these polarizers by fitting the experimental results with theoretical simulations. Our study provides an attractive approach for implementing high-performance optical polarizers by integrating 2D GO films onto Si photonic devices and complements the recent advances made in GO coated nanophotonic devices for linear and nonlinear optics. [52-107] Our study also provides an attractive application for integrated nonlinear devices in general [108-191]

## AUTHOR DECLARATIONS

### Conflict of Interest

The authors have no conflicts to disclose.

### References

[1] Y. Yan, G. Xie, M. P. J. Lavery, H. Huang, N. Ahmed, C. Bao, Y. Ren, Y. Cao, L. Li, Z. Zhao, A. F. Molisch, M. Tur, M. J. Padgett, and A. E. Willner, "High-capacity millimetre-wave communications with orbital angular momentum multiplexing," *Nature Communications*, vol. 5, no. 1, pp. 4876, 2014/09/16, 2014.

[2] D. Dai, L. Liu, S. Gao, D.-X. Xu, and S. He, "Polarization management for silicon photonic integrated circuits," *Laser & Photonics Reviews*, vol. 7, no. 3, pp. 303-328, 2013/05/01, 2013.

[3] J. Chu, K. Zhao, Q. Zhang, and T. Wang, "Construction and performance test of a novel polarization sensor for navigation," *Sensors and Actuators A: Physical*, vol. 148, no. 1, pp. 75-82, 2008/11/04/, 2008.

[4] V. Thilak, D. G. Voelz, and C. D. Creusere, "Polarization-based index of refraction and reflection angle estimation for remote sensing applications," *Applied Optics*, vol. 46, no. 30, pp. 7527-7536, 2007/10/20, 2007.

[5] C.-T. Lee, H.-Y. Lin, and C.-H. Tsai, "Designs of broadband and wide-view patterned polarizers for stereoscopic 3D displays," *Optics Express*, vol. 18, no. 26, pp. 27079-27094, 2010/12/20, 2010.

[6] S. H. Kim, J.-D. Park, and K.-D. Lee, "Fabrication of a nano-wire grid polarizer for brightness
enhancement in liquid crystal display,” *Nanotechnology*, vol. 17, no. 17, pp. 4436, 2006/08/14, 2006.

[7] Y. T. Cho, “Fabrication of wire grid polarizer for spectroscopy application: From ultraviolet to terahertz,” *Applied Spectroscopy Reviews*, vol. 53, no. 2-4, pp. 224-245, 2018/04/21, 2018.

[8] C. He, H. He, J. Chang, B. Chen, H. Ma, and M. J. Booth, “Polarisation optics for biomedical and clinical applications: a review,” *Light: Science & Applications*, vol. 10, no. 1, pp. 194, 2021/09/22, 2021.

[9] Y. Han, and G. Li, “Coherent optical communication using polarization multiple-input-multiple-output,” *Optics Express*, vol. 13, no. 19, pp. 7527-7534, 2005/09/19, 2005.

[10] Z. Zhang, J. Gan, T. Yang, Y. Wu, Q. Li, S. Xu, and Z. Yang, “All-fiber mode-locked laser based on microfiber polarizer,” *Optics Letters*, vol. 40, no. 5, pp. 784-787, 2015/03/01, 2015.

[11] K. Serkowski, D. Mathewson, and V. Ford, “Wavelength dependence of interstellar polarization and ratio of total to selective extinction,” *Astrophysical Journal*, vol. 196, Feb. 15, 1975, pt. 1, p. 261-290, vol. 196, pp. 261-290, 1975.

[12] T. J. Wang, Q. Y. He, J. Y. Gao, Y. Jiang, Z. H. Kang, H. Sun, L. S. Yu, X. F. Yuan, and J. Wu, “Efficient electrooptically Q-switched Er:YSGG laser oscillator-amplifier system with a Glan-Taylor prism polarizer,” *Laser Physics*, vol. 16, no. 12, pp. 1605-1609, 2006/12/01, 2006.

[13] E. Saitoh, Y. Kawaguchi, K. Saitoh, and M. Koshiba, “TE/TM-Pass Polarizer Based on Lithium Niobate on Insulator Ridge Waveguide,” *IEEE Photonics Journal*, vol. 5, no. 2, pp. 6600610-6600610, 2013.

[14] A. Rahnama, T. Dadalyan, K. Mahmoud Aghdami, T. Galstian, and P. R. Herman, “In-Fiber Switchable Polarization Filter Based on Liquid Crystal Filled Hollow-Filament Bragg Gratings,” *Advanced Optical Materials*, vol. 9, no. 19, pp. 2100054, 2021/10/01, 2021.

[15] J. Wang, J.-Y. Yang, I. M. Fazal, N. Ahmed, Y. Yan, H. Huang, Y. Ren, Y. Yue, S. Dolinar, and M. Tur, “Terabit free-space data transmission employing orbital angular momentum multiplexing,” *Nature Photonics*, vol. 6, no. 7, pp. 488-496, 2012.

[16] N. Bozinovic, Y. Yue, Y. Ren, M. Tur, P. Kristensen, H. Huang, A. E. Willner, and S. Ramachandran, “Terabit-scale orbital angular momentum mode division multiplexing in fibers,” *science*, vol. 340, no. 6140, pp. 1545-1548, 2013.

[17] D. Dai, Z. Wang, N. Julian, and J. E. Bowers, “Compact broadband polarizer based on shallowly-etched silicon-on-insulator ridge optical waveguides,” *Optics Express*, vol. 18, no. 26, pp. 27404-27415, 2010/12/20, 2010.

[18] Y. Huang, S. Zhu, H. Zhang, T.-Y. Liow, and G.-Q. Lo, “CMOS compatible horizontal nanoplasmonic slot waveguides TE-pass polarizer on silicon-on-insulator platform,” *Optics Express*, vol. 21, no. 10, pp. 12790-12796, 2013/05/20, 2013.

[19] Z. Li, B. Xu, D. Liang, and A. Pan, “Polarization-Dependent Optical Properties and Optoelectronic Devices of 2D Materials,” *Research*, vol. 2020, 2020.

[20] Q. Bao, H. Zhang, B. Wang, Z. Ni, C. H. Y. X. Lim, Y. Wang, D. Y. Tang, and K. P. Loh, “Broadband graphene polarizer,” *Nature Photonics*, vol. 5, no. 7, pp. 411-415, 2011/07/01, 2011.

[21] H. Lin, Y. Song, Y. Huang, D. Kita, S. Deckoff-Jones, K. Wang, L. Li, J. Li, H. Zheng, Z. Luo, H. Wang, S. Novak, A. Yadav, C.-C. Huang, R.-J. Shiue, D. Englund, T. Gu, D. Hewak, K. Richardson, J. Kong, and J. Hu, “Chalcogenide glass-on-graphene photonics,” *Nature Photonics*, vol. 11, no. 12, pp. 798-805, 2017/12/01, 2017.

[22] J. T. Kim, and C.-G. Choi, “Graphene-based polymer waveguide polarizer,” *Optics Express*, vol. 20, no. 4, pp. 3556-3562, 2012/02/13, 2012.

[23] C. Pei, L. Yang, G. Wang, Y. Wang, X. Jiang, Y. Hao, Y. Li, and J. Yang, “Broadband Graphene/Glass Hybrid Waveguide Polarizer,” *IEEE Photonics Technology Letters*, vol. 27, no. 9, pp. 927-930, 2015.
enhancement in liquid crystal display,” *Nanotechnology*, vol. 17, no. 17, pp. 4436, 2006/08/14, 2006.

[7] Y. T. Cho, “Fabrication of wire grid polarizer for spectroscopy application: From ultraviolet to terahertz,” *Applied Spectroscopy Reviews*, vol. 53, no. 2-4, pp. 224-245, 2018/04/21, 2018.

[8] C. He, H. He, J. Chang, B. Chen, H. Ma, and M. J. Booth, “Polarisation optics for biomedical and clinical applications: a review,” *Light: Science & Applications*, vol. 10, no. 1, pp. 194, 2021/09/22, 2021.

[9] Y. Han, and G. Li, “Coherent optical communication using polarization multiple-input-multiple-output,” *Optics Express*, vol. 13, no. 19, pp. 7527-7534, 2005/09/19, 2005.

[10] Z. Zhang, J. Gan, T. Yang, Y. Wu, Q. Li, S. Xu, and Z. Yang, “All-fiber mode-locked laser based on microfiber polarizer,” *Optics Letters*, vol. 40, no. 5, pp. 784-787, 2015/03/01, 2015.

[11] K. Serkowski, D. Mathewson, and V. Ford, “Wavelength dependence of interstellar polarization and ratio of total to selective extinction,” *Astrophysical Journal*, vol. 196, Feb. 15, 1975, pt. 1, p. 261-290, vol. 196, pp. 261-290, 1975.

[12] T. J. Wang, Q. Y. He, J. Y. Gao, Y. Jiang, Z. H. Kang, H. Sun, L. S. Yu, X. F. Yuan, and J. Wu, “Efficient electrooptically Q-switched Er:YSGG laser oscillator-amplifier system with a Glan-Taylor prism polarizer,” *Laser Physics*, vol. 16, no. 12, pp. 1605-1609, 2006/12/01, 2006.

[13] E. Saitoh, Y. Kawaguchi, K. Saitoh, and M. Koshiba, “TE/TM-Pass Polarizer Based on Lithium Niobate on Insulator Ridge Waveguide,” *IEEE Photonics Journal*, vol. 5, no. 2, pp. 6600610-6600610, 2013.

[14] A. Rahnama, T. Dadalyan, K. Mahmoud Aghdami, T. Galstian, and P. R. Herman, “In-Fiber Switchable Polarization Filter Based on Liquid Crystal Filled Hollow-Filament Bragg Gratings,” *Advanced Optical Materials*, vol. 9, no. 19, pp. 2100054, 2021/10/01, 2021.

[15] J. Wang, J.-Y. Yang, I. M. Fazal, N. Ahmed, Y. Yan, H. Huang, Y. Ren, Y. Yue, S. Dolinar, and M. Tur, “Terabit free-space data transmission employing orbital angular momentum multiplexing,” *Nature Photonics*, vol. 6, no. 7, pp. 488-496, 2012.

[16] N. Bozinovic, Y. Yue, Y. Ren, M. Tur, P. Kristensen, H. Huang, A. E. Willner, and S. Ramachandran, “Terabit-scale orbital angular momentum mode division multiplexing in fibers,” *science*, vol. 340, no. 6140, pp. 1545-1548, 2013.

[17] D. Dai, Z. Wang, N. Julian, and J. E. Bowers, “Compact broadband polarizer based on shallowly-etched silicon-on-insulator ridge optical waveguides,” *Optics Express*, vol. 18, no. 26, pp. 27404-27415, 2010/12/20, 2010.

[18] Y. Huang, S. Zhu, H. Zhang, T.-Y. Liow, and G.-Q. Lo, “CMOS compatible horizontal nanoplasmonic slot waveguides TE-pass polarizer on silicon-on-insulator platform,” *Optics Express*, vol. 21, no. 10, pp. 12790-12796, 2013/05/20, 2013.

[19] Z. Li, B. Xu, D. Liang, and A. Pan, “Polarization-Dependent Optical Properties and Optoelectronic Devices of 2D Materials,” *Research*, vol. 2020, 2020.

[20] Q. Bao, H. Zhang, B. Wang, Z. Ni, C. H. Y. X. Lim, Y. Wang, D. Y. Tang, and K. P. Loh, “Broadband graphene polarizer,” *Nature Photonics*, vol. 5, no. 7, pp. 411-415, 2011/07/01, 2011.

[21] H. Lin, Y. Song, Y. Huang, D. Kita, S. Deckoff-Jones, K. Wang, L. Li, J. Li, H. Zheng, Z. Luo, H. Wang, S. Novak, A. Yadav, C.-C. Huang, R.-J. Shiue, D. Englund, T. Gu, D. Hewak, K. Richardson, J. Kong, and J. Hu, “Chalcogenide glass-on-graphene photonics,” *Nature Photonics*, vol. 11, no. 12, pp. 798-805, 2017/12/01, 2017.

[22] J. T. Kim, and C.-G. Choi, “Graphene-based polymer waveguide polarizer,” *Optics Express*, vol. 20, no. 4, pp. 3556-3562, 2012/02/13, 2012.

[23] C. Pei, L. Yang, G. Wang, Y. Wang, X. Jiang, Y. Hao, Y. Li, and J. Yang, “Broadband Graphene/Glass Hybrid Waveguide Polarizer,” *IEEE Photonics Technology Letters*, vol. 27, no. 9, pp. 927-930, 2015.
[24] W. H. Lim, Y. K. Yap, W. Y. Chong, C. H. Pua, N. M. Huang, R. M. De La Rue, and H. Ahmad, "Graphene oxide-based waveguide polariser: From thin film to quasi-bulk," *Optics Express*, vol. 22, no. 9, pp. 11090-11098, 2014/05/05, 2014.

[25] J. Wu, Y. Yang, Y. Qu, X. Xu, Y. Liang, S. T. Chu, B. E. Little, R. Morandotti, B. Jia, and D. J. Moss, "Graphene Oxide Waveguide and Micro-Ring Resonator Polarizers," *Laser & Photonics Reviews*, vol. 13, no. 9, pp. 1900056, 2019.

[26] Y. Tan, R. He, C. Cheng, D. Wang, Y. Chen, and F. Chen, "Polarization-dependent optical absorption of MoS2 for refractive index sensing," *Scientific Reports*, vol. 4, no. 1, pp. 7523, 2014/12/17, 2014.

[27] S. Sathiyan, H. Ahmad, W. Y. Chong, S. H. Lee, and S. Sivabalan, "Evolution of the Polarizing Effect of $\text{MoS}_{2}$," *IEEE Photonics Journal*, vol. 7, no. 6, pp. 1-10, 2015.

[28] F. Zhou, and J. Zhang, "Polarization-Independent Black-Phosphorus Polarizer in Visible Regime," *IEEE Photonics Technology Letters*, vol. 29, no. 22, pp. 1923-1926, 2017.

[29] J. Wu, H. Lin, D. J. Moss, K. P. Loh, and B. Jia, "Graphene oxide for photonics, electronics and optoelectronics," *Nature Reviews Chemistry*, vol. 7, no. 3, pp. 162-183, 2023/03/01, 2023.

[30] J. Wu, L. Jia, Y. Zhang, Y. Qu, B. Jia, and D. J. Moss, "Graphene Oxide for Integrated Photonics and Flat Optics," *Advanced Materials*, vol. 33, no. 3, pp. 2006415, 2021.

[31] Y. Yang, Y. Zhang, J. Zhang, X. Zheng, Z. Gan, H. Lin, M. Hong, and B. Jia, "Graphene Metamaterial 3D Conformal Coating for Enhanced Light Harvesting," *ACS Nano*, vol. 17, no. 3, pp. 2611-2619, 2023/02/14, 2023.

[32] K. P. Loh, Q. Bao, G. Eda, and M. Chhowalla, "Graphene oxide as a chemically tunable platform for optical applications," *Nature Chemistry*, vol. 2, no. 12, pp. 1015-1024, 2010/12/01, 2010.

[33] M. F. El-Kady, V. Strong, S. Dubin, and R. B. Kaner, "Laser Scribing of High-Performance and Flexible Graphene-Based Electrochemical Capacitors," *Science*, vol. 335, no. 6074, pp. 1326-1330, 2012.

[34] F. Bonaccorso, Z. Sun, T. Hasan, and A. C. Ferrari, "Graphene photonics and optoelectronics," *Nature Photonics*, vol. 4, no. 9, pp. 611-622, 2010/09/01, 2010.

[35] C. T. Phare, Y.-H. Daniel Lee, J. Cardenas, and M. Lipson, "Graphene electro-optic modulator with 30 GHz bandwidth," *Nature photonics*, vol. 9, no. 8, pp. 511-514, 2015.

[36] I. Alonso Calafell, L. A. Rozema, D. Alcaraz Iranzo, A. Trenti, P. K. Jenke, J. D. Cox, A. Kumar, H. Bieliaiev, S. Nanot, C. Peng, D. K. Efetov, J.-Y. Hong, J. Kong, D. R. Englund, F. J. García de Abajo, F. H. L. Koppens, and P. Walther, "Giant enhancement of third-harmonic generation in graphene–metal heterostructures," *Nature Nanotechnology*, vol. 16, no. 3, pp. 318-324, 2021/03/01, 2021.

[37] H. Lin, B. C. P. Sturmberg, K.-T. Lin, Y. Yang, X. Zheng, T. K. Chong, C. M. de Sterke, and B. Jia, "A 90-nm-thick graphene metamaterial for strong and extremely broadband absorption of unpolarized light," *Nature Photonics*, vol. 13, no. 4, pp. 270-276, 2019/04/01, 2019.

[38] D. Dai, J. Bauters, and J. E. Bowers, "Passive technologies for future large-scale photonic integrated circuits on silicon: polarization handling, light non-reciprocity and loss reduction," *Light: Science & Applications*, vol. 1, no. 3, pp. e1-e1, 2012/03/01, 2012.

[39] J. Wu, Y. Yang, Y. Qu, L. Jia, Y. Zhang, X. Xu, S. T. Chu, B. E. Little, R. Morandotti, B. Jia, and D. J. Moss, "2D Layered Graphene Oxide Films Integrated with Micro-Ring Resonators for Enhanced Nonlinear Optics," *Small*, vol. 16, no. 16, pp. 1906563, 2020/04/01, 2020.

[40] Y. Zhang, J. Wu, L. Jia, Y. Qu, Y. Yang, B. Jia, and D. J. Moss, "Graphene Oxide for Nonlinear Integrated Photonics," *Laser & Photonics Reviews*, vol. 17, no. 3, pp. 2200512, 2023.

[41] P. W. Smith, and W. J. Tomlinson, "Bistable optical devices promise subpicosecond switching," *IEEE Spectrum*, vol. 18, pp. 26-33, June 01, 1981, 1981.

[42] H. Gibbs, *Optical bistability: controlling light with light*: Elsevier, 2012.
[24] W. H. Lim, Y. K. Yap, W. Y. Chong, C. H. Pua, N. M. Huang, R. M. De La Rue, and H. Ahmad, "Graphene oxide-based waveguide polariser: From thin film to quasi-bulk," *Optics Express*, vol. 22, no. 9, pp. 11090-11098, 2014/05/05, 2014.

[25] J. Wu, Y. Yang, Y. Qu, X. Xu, Y. Liang, S. T. Chu, B. E. Little, R. Morandotti, B. Jia, and D. J. Moss, "Graphene Oxide Waveguide and Micro-Ring Resonator Polarizers," *Laser & Photonics Reviews*, vol. 13, no. 9, pp. 1900056, 2019.

[26] Y. Tan, R. He, C. Cheng, D. Wang, Y. Chen, and F. Chen, "Polarization-dependent optical absorption of MoS2 for refractive index sensing," *Scientific Reports*, vol. 4, no. 1, pp. 7523, 2014/12/17, 2014.

[27] S. Sathiyan, H. Ahmad, W. Y. Chong, S. H. Lee, and S. Sivabalan, "Evolution of the Polarizing Effect of $\text{MoS}_{2}$," *IEEE Photonics Journal*, vol. 7, no. 6, pp. 1-10, 2015.

[28] F. Zhou, and J. Zhang, "Polarization-Independent Black-Phosphorus Polarizer in Visible Regime," *IEEE Photonics Technology Letters*, vol. 29, no. 22, pp. 1923-1926, 2017.

[29] J. Wu, H. Lin, D. J. Moss, K. P. Loh, and B. Jia, "Graphene oxide for photonics, electronics and optoelectronics," *Nature Reviews Chemistry*, vol. 7, no. 3, pp. 162-183, 2023/03/01, 2023.

[30] J. Wu, L. Jia, Y. Zhang, Y. Qu, B. Jia, and D. J. Moss, "Graphene Oxide for Integrated Photonics and Flat Optics," *Advanced Materials*, vol. 33, no. 3, pp. 2006415, 2021.

[31] Y. Yang, Y. Zhang, J. Zhang, X. Zheng, Z. Gan, H. Lin, M. Hong, and B. Jia, "Graphene Metamaterial 3D Conformal Coating for Enhanced Light Harvesting," *ACS Nano*, vol. 17, no. 3, pp. 2611-2619, 2023/02/14, 2023.

[32] K. P. Loh, Q. Bao, G. Eda, and M. Chhowalla, "Graphene oxide as a chemically tunable platform for optical applications," *Nature Chemistry*, vol. 2, no. 12, pp. 1015-1024, 2010/12/01, 2010.

[33] M. F. El-Kady, V. Strong, S. Dubin, and R. B. Kaner, "Laser Scribing of High-Performance and Flexible Graphene-Based Electrochemical Capacitors," *Science*, vol. 335, no. 6074, pp. 1326-1330, 2012.

[34] F. Bonaccorso, Z. Sun, T. Hasan, and A. C. Ferrari, "Graphene photonics and optoelectronics," *Nature Photonics*, vol. 4, no. 9, pp. 611-622, 2010/09/01, 2010.

[35] C. T. Phare, Y.-H. Daniel Lee, J. Cardenas, and M. Lipson, "Graphene electro-optic modulator with 30 GHz bandwidth," *Nature photonics*, vol. 9, no. 8, pp. 511-514, 2015.

[36] I. Alonso Calafell, L. A. Rozema, D. Alcaraz Iranzo, A. Trenti, P. K. Jenke, J. D. Cox, A. Kumar, H. Bieliaiev, S. Nanot, C. Peng, D. K. Efetov, J.-Y. Hong, J. Kong, D. R. Englund, F. J. García de Abajo, F. H. L. Koppens, and P. Walther, "Giant enhancement of third-harmonic generation in graphene–metal heterostructures," *Nature Nanotechnology*, vol. 16, no. 3, pp. 318-324, 2021/03/01, 2021.

[37] H. Lin, B. C. P. Sturmberg, K.-T. Lin, Y. Yang, X. Zheng, T. K. Chong, C. M. de Sterke, and B. Jia, "A 90-nm-thick graphene metamaterial for strong and extremely broadband absorption of unpolarized light," *Nature Photonics*, vol. 13, no. 4, pp. 270-276, 2019/04/01, 2019.

[38] D. Dai, J. Bauters, and J. E. Bowers, "Passive technologies for future large-scale photonic integrated circuits on silicon: polarization handling, light non-reciprocity and loss reduction," *Light: Science & Applications*, vol. 1, no. 3, pp. e1-e1, 2012/03/01, 2012.

[39] J. Wu, Y. Yang, Y. Qu, L. Jia, Y. Zhang, X. Xu, S. T. Chu, B. E. Little, R. Morandotti, B. Jia, and D. J. Moss, "2D Layered Graphene Oxide Films Integrated with Micro-Ring Resonators for Enhanced Nonlinear Optics," *Small*, vol. 16, no. 16, pp. 1906563, 2020/04/01, 2020.

[40] Y. Zhang, J. Wu, L. Jia, Y. Qu, Y. Yang, B. Jia, and D. J. Moss, "Graphene Oxide for Nonlinear Integrated Photonics," *Laser & Photonics Reviews*, vol. 17, no. 3, pp. 2200512, 2023.

[41] P. W. Smith, and W. J. Tomlinson, "Bistable optical devices promise subpicosecond switching," *IEEE Spectrum*, vol. 18, pp. 26-33, June 01, 1981, 1981.

[42] H. Gibbs, *Optical bistability: controlling light with light*: Elsevier, 2012.
[43] H. Arianfard, S. Juodkazis, D. J. Moss, and J. Wu, "Sagnac interference in integrated photonics," *Applied Physics Reviews*, vol. 10, no. 1, pp. 011309, 2023/03/01, 2023.

44. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis, and David J. Moss, "Optical analogs of Rabi splitting in integrated waveguide-coupled resonators", *Advanced Physics Research* 2 2200123 (2023). DOI: 10.1002/apxr.202200123.

45. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis, and David J. Moss, "Spectral shaping based on optical waveguides with advanced Sagnac loop reflectors", Paper No. PW22O-OE201-20, SPIE-Opto, Integrated Optics: Devices, Materials, and Technologies XXVI, SPIE Photonics West, San Francisco CA January 22 - 27 (2022). doi: 10.1117/12.2607902

46. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis, David J. Moss, "Spectral Shaping Based on Integrated Coupled Sagnac Loop Reflectors Formed by a Self-Coupled Wire Waveguide", IEEE Photonics Technology Letters vol. 33 (13) 680-683 (2021). DOI:10.1109/LPT.2021.3088089.

47. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis and David J. Moss, "Three Waveguide Coupled Sagnac Loop Reflectors for Advanced Spectral Engineering", Journal of Lightwave Technology vol. 39 (11) 3478-3487 (2021). DOI: 10.1109/JLT.2021.3066256.

48. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis and David J. Moss, "Advanced Multi-Functional Integrated Photonic Filters based on Coupled Sagnac Loop Reflectors", Journal of Lightwave Technology vol. 39 Issue: 5, pp.1400-1408 (2021). DOI:10.1109/JLT.2020.3037559.

49. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis and David J. Moss, "Advanced multi-functional integrated photonic filters based on coupled Sagnac loop reflectors", Paper 11691-4, PW21O-OE203-44, Silicon Photonics XVI, SPIE Photonics West, San Francisco CA March 6-11 (2021). doi.org/10.1117/12.2584020

50. Jiayang Wu, Tania Moein, Xingyuan Xu, and David J. Moss, "Advanced photonic filters via cascaded Sagnac loop reflector resonators in silicon-on-insulator integrated nanowires", Applied Physics Letters Photonics vol. 3 046102 (2018). DOI:/10.1063/1.5025833

51. Jiayang Wu, Tania Moein, Xingyuan Xu, Guanghui Ren, Arnan Mitchell, and David J. Moss, "Micro-ring resonator quality factor enhancement via an integrated Fabry-Perot cavity", Applied Physics Letters Photonics vol. 2 056103 (2017). doi: 10.1063/1.4981392.

52. Zhang, Y. et al. Enhanced Kerr nonlinearity and nonlinear figure of merit in silicon nanowires integrated with 2d graphene oxide films. ACS Appl. Mater. Interfaces Vol. 12, 33094-33103 (2020).

53. Qu, Y. et al. Enhanced four-wave mixing in silicon nitride waveguides integrated with 2d layered graphene oxide films. Advanced Optical Materials Vol. 8, 2001048 (2020).

54. Jia, L. et al. Highly nonlinear BiOBr nanoflakes for hybrid integrated photonics. APL Photonics Vol. 4, 090802 (2019).

55. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Linnan Jia, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Enhanced supercontinuum generated in SiN waveguides coated with GO films", *Advanced Materials Technologies* 8 (1) 2201796 (2023). DOI:10.1002/admt.202201796.

56. Yuning Zhang, Jiayang Wu, Linnan Jia, Yang Qu, Baohua Jia, and David J. Moss, "Graphene oxide for nonlinear integrated photonics", *Laser and Photonics Reviews* 17 2200512 (2023). DOI:10.1002/lpor.202200512.
[43] H. Arianfard, S. Juodkazis, D. J. Moss, and J. Wu, "Sagnac interference in integrated photonics," *Applied Physics Reviews*, vol. 10, no. 1, pp. 011309, 2023/03/01, 2023.

44. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis, and David J. Moss, "Optical analogs of Rabi splitting in integrated waveguide-coupled resonators", *Advanced Physics Research* 2 2200123 (2023). DOI: 10.1002/apxr.202200123.

45. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis, and David J. Moss, "Spectral shaping based on optical waveguides with advanced Sagnac loop reflectors", Paper No. PW22O-OE201-20, SPIE-Opto, Integrated Optics: Devices, Materials, and Technologies XXVI, SPIE Photonics West, San Francisco CA January 22 - 27 (2022). doi: 10.1117/12.2607902

46. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis, David J. Moss, "Spectral Shaping Based on Integrated Coupled Sagnac Loop Reflectors Formed by a Self-Coupled Wire Waveguide", IEEE Photonics Technology Letters vol. 33 (13) 680-683 (2021). DOI:10.1109/LPT.2021.3088089.

47. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis and David J. Moss, "Three Waveguide Coupled Sagnac Loop Reflectors for Advanced Spectral Engineering", Journal of Lightwave Technology vol. 39 (11) 3478-3487 (2021). DOI: 10.1109/JLT.2021.3066256.

48. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis and David J. Moss, "Advanced Multi-Functional Integrated Photonic Filters based on Coupled Sagnac Loop Reflectors", Journal of Lightwave Technology vol. 39 Issue: 5, pp.1400-1408 (2021). DOI:10.1109/JLT.2020.3037559.

49. Hamed Arianfard, Jiayang Wu, Saulius Juodkazis and David J. Moss, "Advanced multi-functional integrated photonic filters based on coupled Sagnac loop reflectors", Paper 11691-4, PW21O-OE203-44, Silicon Photonics XVI, SPIE Photonics West, San Francisco CA March 6-11 (2021). doi.org/10.1117/12.2584020

50. Jiayang Wu, Tania Moein, Xingyuan Xu, and David J. Moss, "Advanced photonic filters via cascaded Sagnac loop reflector resonators in silicon-on-insulator integrated nanowires", Applied Physics Letters Photonics vol. 3 046102 (2018). DOI:/10.1063/1.5025833

51. Jiayang Wu, Tania Moein, Xingyuan Xu, Guanghui Ren, Arnan Mitchell, and David J. Moss, "Micro-ring resonator quality factor enhancement via an integrated Fabry-Perot cavity", Applied Physics Letters Photonics vol. 2 056103 (2017). doi: 10.1063/1.4981392.

52. Zhang, Y. et al. Enhanced Kerr nonlinearity and nonlinear figure of merit in silicon nanowires integrated with 2d graphene oxide films. ACS Appl. Mater. Interfaces Vol. 12, 33094-33103 (2020).

53. Qu, Y. et al. Enhanced four-wave mixing in silicon nitride waveguides integrated with 2d layered graphene oxide films. Advanced Optical Materials Vol. 8, 2001048 (2020).

54. Jia, L. et al. Highly nonlinear BiOBr nanoflakes for hybrid integrated photonics. APL Photonics Vol. 4, 090802 (2019).

55. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Linnan Jia, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Enhanced supercontinuum generated in SiN waveguides coated with GO films", *Advanced Materials Technologies* 8 (1) 2201796 (2023). DOI:10.1002/admt.202201796.

56. Yuning Zhang, Jiayang Wu, Linnan Jia, Yang Qu, Baohua Jia, and David J. Moss, "Graphene oxide for nonlinear integrated photonics", *Laser and Photonics Reviews* 17 2200512 (2023). DOI:10.1002/lpor.202200512.
57. Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Linnan Jia, Baohua Jia, and David J. Moss, "Photo thermal tuning in GO-coated integrated waveguides", Micromachines Vol. 13 1194 (2022). doi.org/10.3390/mi13081194

58. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Houssein El Dirani, Romain Crochemore, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Enhanced self-phase modulation in silicon nitride waveguides integrated with 2D graphene oxide films", IEEE Journal of Selected Topics in Quantum Electronics Vol. 29 (1) 5100413 (2023). DOI: 10.1109/JSTQE.2022.3177385

59. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Enhanced spectral broadening of femtosecond optical pulses in silicon nanowires integrated with 2D graphene oxide films", Micromachines Vol. 13 756 (2022). DOI:10.3390/mi13050756.

60. Junkai Hu, Jiayang Wu, Wenbo Liu, Di Jin, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Duan Huang, Baohua Jia, and David J. Moss, "2D graphene oxide: a versatile thermo-optic material", Advanced Functional Materials (2024).

61. Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Linnan Jia, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Optical parametric amplifiers based on silicon nitride waveguides integrated with 2D graphene oxide films", Light: Advanced Manufacturing 4 39 (2023). https://doi.org/10.37188/lam.2023.039.

62. Di Jin, Wenbo Liu, Linnan Jia, Junkai Hu, Duan Huang, Jiayang Wu, Baohua Jia, and David J. Moss, "Strong and layer-dependent nonlinear optical absorption in 2D layered MXene films", Small Science (2024).

63. Linnan Jia, Jiayang Wu, Yuning Zhang, Yang Qu, Baohua Jia, Zhigang Chen, and David J. Moss, "Fabrication Technologies for the On-Chip Integration of 2D Materials", Small: Methods Vol. 6, 2101435 (2022). DOI:10.1002/smtd.202101435.

64. Yuning Zhang, Jiayang Wu, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Design and optimization of four-wave mixing in microring resonators integrated with 2D graphene oxide films", Journal of Lightwave Technology Vol. 39 (20) 6553-6562 (2021). DOI:10.1109/JLT.2021.3101292.

65. Yuning Zhang, Jiayang Wu, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Optimizing the Kerr nonlinear optical performance of silicon waveguides integrated with 2D graphene oxide films", Journal of Lightwave Technology Vol. 39 (14) 4671-4683 (2021). DOI: 10.1109/JLT.2021.3069733.

66. Yang Qu, Jiayang Wu, Yuning Zhang, Yao Liang, Baohua Jia, and David J. Moss, "Analysis of four-wave mixing in silicon nitride waveguides integrated with 2D layered graphene oxide films", Journal of Lightwave Technology Vol. 39 (9) 2902-2910 (2021). DOI: 10.1109/JLT.2021.3059721.

67. Y. Qu, J. Wu, Y. Zhang, L. Jia, Y. Yang, X. Xu, S. T. Chu, B. E. Little, R. Morandotti, B. Jia, and D. J. Moss, "Graphene oxide for enhanced optical nonlinear performance in CMOS compatible integrated devices", Paper No. 11688-30, PW21O-OE109-36, 2D Photonic Materials and Devices IV, SPIE Photonics West, San Francisco CA March 6-11 (2021). doi.org/10.1117/12.2583978

68. Yang Qu, Jiayang Wu, Yunyi Yang, Yuning Zhang, Yao Liang, Houssein El Dirani, Romain Crochemore, Pierre Demongodin, Corrado Sciancalepore, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Enhanced nonlinear four-wave mixing in silicon nitride waveguides integrated
57. Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Linnan Jia, Baohua Jia, and David J. Moss, "Photo thermal tuning in GO-coated integrated waveguides", Micromachines Vol. 13 1194 (2022). doi.org/10.3390/mi13081194

58. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Houssein El Dirani, Romain Crochemore, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Enhanced self-phase modulation in silicon nitride waveguides integrated with 2D graphene oxide films", IEEE Journal of Selected Topics in Quantum Electronics Vol. 29 (1) 5100413 (2023). DOI: 10.1109/JSTQE.2022.3177385

59. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Enhanced spectral broadening of femtosecond optical pulses in silicon nanowires integrated with 2D graphene oxide films", Micromachines Vol. 13 756 (2022). DOI:10.3390/mi13050756.

60. Junkai Hu, Jiayang Wu, Wenbo Liu, Di Jin, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Duan Huang, Baohua Jia, and David J. Moss, "2D graphene oxide: a versatile thermo-optic material", Advanced Functional Materials (2024).

61. Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Linnan Jia, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Optical parametric amplifiers based on silicon nitride waveguides integrated with 2D graphene oxide films", Light: Advanced Manufacturing 4 39 (2023). https://doi.org/10.37188/lam.2023.039.

62. Di Jin, Wenbo Liu, Linnan Jia, Junkai Hu, Duan Huang, Jiayang Wu, Baohua Jia, and David J. Moss, "Strong and layer-dependent nonlinear optical absorption in 2D layered MXene films", Small Science (2024).

63. Linnan Jia, Jiayang Wu, Yuning Zhang, Yang Qu, Baohua Jia, Zhigang Chen, and David J. Moss, "Fabrication Technologies for the On-Chip Integration of 2D Materials", Small: Methods Vol. 6, 2101435 (2022). DOI:10.1002/smtd.202101435.

64. Yuning Zhang, Jiayang Wu, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Design and optimization of four-wave mixing in microring resonators integrated with 2D graphene oxide films", Journal of Lightwave Technology Vol. 39 (20) 6553-6562 (2021). DOI:10.1109/JLT.2021.3101292.

65. Yuning Zhang, Jiayang Wu, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Optimizing the Kerr nonlinear optical performance of silicon waveguides integrated with 2D graphene oxide films", Journal of Lightwave Technology Vol. 39 (14) 4671-4683 (2021). DOI: 10.1109/JLT.2021.3069733.

66. Yang Qu, Jiayang Wu, Yuning Zhang, Yao Liang, Baohua Jia, and David J. Moss, "Analysis of four-wave mixing in silicon nitride waveguides integrated with 2D layered graphene oxide films", Journal of Lightwave Technology Vol. 39 (9) 2902-2910 (2021). DOI: 10.1109/JLT.2021.3059721.

67. Y. Qu, J. Wu, Y. Zhang, L. Jia, Y. Yang, X. Xu, S. T. Chu, B. E. Little, R. Morandotti, B. Jia, and D. J. Moss, "Graphene oxide for enhanced optical nonlinear performance in CMOS compatible integrated devices", Paper No. 11688-30, PW21O-OE109-36, 2D Photonic Materials and Devices IV, SPIE Photonics West, San Francisco CA March 6-11 (2021). doi.org/10.1117/12.2583978

68. Yang Qu, Jiayang Wu, Yunyi Yang, Yuning Zhang, Yao Liang, Houssein El Dirani, Romain Crochemore, Pierre Demongodin, Corrado Sciancalepore, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Enhanced nonlinear four-wave mixing in silicon nitride waveguides integrated
with 2D layered graphene oxide films", Advanced Optical Materials vol. 8 (21) 2001048 (2020). DOI: 10.1002/adom.202001048. arXiv:2006.14944.

69. Yuning Zhang, Yang Qu, Jiayang Wu, Linnan Jia, Yunyi Yang, Xingyuan Xu, Baohua Jia, and David J. Moss, "Enhanced Kerr nonlinearity and nonlinear figure of merit in silicon nanowires integrated with 2D graphene oxide films", ACS Applied Materials and Interfaces vol. 12 (29) 33094-33103 June 29 (2020). DOI:10.1021/acsami.0c07852

70. Jiayang Wu, Yunyi Yang, Yang Qu, Xingyuan Xu, Yao Liang, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Graphene oxide waveguide polarizers and polarization selective micro-ring resonators", Paper 11282-29, SPIE Photonics West, San Francisco, CA, 4 - 7 February (2020). doi: 10.1117/12.2544584

71. Yunyi Yang, Jiayang Wu, Xingyuan Xu, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Enhanced four-wave mixing in graphene oxide coated waveguides", Applied Physics Letters Photonics vol. 3 120803 (2018). doi: 10.1063/1.5045509.

72. Linnan Jia, Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Baohua Jia, and David J. Moss, "Third-order optical nonlinearities of 2D materials at telecommunications wavelengths", Micromachines (MDPI), 14, 307 (2023). https://doi.org/10.3390/mi14020307.

73. Linnan Jia, Dandan Cui, Jiayang Wu, Haifeng Feng, Tieshan Yang, Yunyi Yang, Yi Du, Weichang Hao, Baohua Jia, David J. Moss, "BiOBr nanoflakes with strong nonlinear optical properties towards hybrid integrated photonic devices", Applied Physics Letters Photonics vol. 4 090802 vol. (2019). DOI: 10.1063/1.5116621

74. Linnan Jia, Jiayang Wu, Yunyi Yang, Yi Du, Baohua Jia, David J. Moss, "Large Third-Order Optical Kerr Nonlinearity in Nanometer-Thick PdSe2 2D Dichalcogenide Films: Implications for Nonlinear Photonic Devices", ACS Applied Nano Materials vol. 3 (7) 6876-6883 (2020). DOI:10.1021/acsanm.0c01239.

75. Jiayang Wu, Tania Moein, Xingyuan Xu, and David J. Moss, "Advanced photonic filters via cascaded Sagnac loop reflector resonators in silicon-on-insulator integrated nanowires", Applied Physics Letters Photonics vol. 3 046102 (2018). DOI:/10.1063/1.5025833

76. Jiayang Wu, Tania Moein, Xingyuan Xu, Guanghui Ren, Arnan Mitchell, and David J. Moss, "Micro-ring resonator quality factor enhancement via an integrated Fabry-Perot cavity", Applied Physics Letters Photonics vol. 2 056103 (2017). doi: 10.1063/1.4981392.

77. Wu, J. et al. 2D layered graphene oxide films integrated with micro-ring resonators for enhanced nonlinear optics. Small Vol. 16, 1906563 (2020).

78. Wu, J. et al. Graphene oxide waveguide and micro-ring resonator polarizers. Laser Photonics Rev. Vol. 13, 1900056 (2019).

79. Zhang, Y. et al. Enhanced Kerr nonlinearity and nonlinear figure of merit in silicon nanowires integrated with 2d graphene oxide films. ACS Appl. Mater. Interfaces Vol. 12, 33094-33103 (2020).

80. Qu, Y. et al. Enhanced four-wave mixing in silicon nitride waveguides integrated with 2d layered graphene oxide films. Advanced Optical Materials Vol. 8, 2001048 (2020).

81. Jia, L. et al. Highly nonlinear BiOBr nanoflakes for hybrid integrated photonics. APL Photonics Vol. 4, 090802 (2019).

82. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Linnan Jia, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David
with 2D layered graphene oxide films", Advanced Optical Materials vol. 8 (21) 2001048 (2020). DOI: 10.1002/adom.202001048. arXiv:2006.14944.

69. Yuning Zhang, Yang Qu, Jiayang Wu, Linnan Jia, Yunyi Yang, Xingyuan Xu, Baohua Jia, and David J. Moss, "Enhanced Kerr nonlinearity and nonlinear figure of merit in silicon nanowires integrated with 2D graphene oxide films", ACS Applied Materials and Interfaces vol. 12 (29) 33094-33103 June 29 (2020). DOI:10.1021/acsami.0c07852

70. Jiayang Wu, Yunyi Yang, Yang Qu, Xingyuan Xu, Yao Liang, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Graphene oxide waveguide polarizers and polarization selective micro-ring resonators", Paper 11282-29, SPIE Photonics West, San Francisco, CA, 4 - 7 February (2020). doi: 10.1117/12.2544584

71. Yunyi Yang, Jiayang Wu, Xingyuan Xu, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Enhanced four-wave mixing in graphene oxide coated waveguides", Applied Physics Letters Photonics vol. 3 120803 (2018). doi: 10.1063/1.5045509.

72. Linnan Jia, Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Baohua Jia, and David J. Moss, "Third-order optical nonlinearities of 2D materials at telecommunications wavelengths", Micromachines (MDPI), 14, 307 (2023). https://doi.org/10.3390/mi14020307.

73. Linnan Jia, Dandan Cui, Jiayang Wu, Haifeng Feng, Tieshan Yang, Yunyi Yang, Yi Du, Weichang Hao, Baohua Jia, David J. Moss, "BiOBr nanoflakes with strong nonlinear optical properties towards hybrid integrated photonic devices", Applied Physics Letters Photonics vol. 4 090802 vol. (2019). DOI: 10.1063/1.5116621

74. Linnan Jia, Jiayang Wu, Yunyi Yang, Yi Du, Baohua Jia, David J. Moss, "Large Third-Order Optical Kerr Nonlinearity in Nanometer-Thick PdSe2 2D Dichalcogenide Films: Implications for Nonlinear Photonic Devices", ACS Applied Nano Materials vol. 3 (7) 6876-6883 (2020). DOI:10.1021/acsanm.0c01239.

75. Jiayang Wu, Tania Moein, Xingyuan Xu, and David J. Moss, "Advanced photonic filters via cascaded Sagnac loop reflector resonators in silicon-on-insulator integrated nanowires", Applied Physics Letters Photonics vol. 3 046102 (2018). DOI:/10.1063/1.5025833

76. Jiayang Wu, Tania Moein, Xingyuan Xu, Guanghui Ren, Arnan Mitchell, and David J. Moss, "Micro-ring resonator quality factor enhancement via an integrated Fabry-Perot cavity", Applied Physics Letters Photonics vol. 2 056103 (2017). doi: 10.1063/1.4981392.

77. Wu, J. et al. 2D layered graphene oxide films integrated with micro-ring resonators for enhanced nonlinear optics. Small Vol. 16, 1906563 (2020).

78. Wu, J. et al. Graphene oxide waveguide and micro-ring resonator polarizers. Laser Photonics Rev. Vol. 13, 1900056 (2019).

79. Zhang, Y. et al. Enhanced Kerr nonlinearity and nonlinear figure of merit in silicon nanowires integrated with 2d graphene oxide films. ACS Appl. Mater. Interfaces Vol. 12, 33094-33103 (2020).

80. Qu, Y. et al. Enhanced four-wave mixing in silicon nitride waveguides integrated with 2d layered graphene oxide films. Advanced Optical Materials Vol. 8, 2001048 (2020).

81. Jia, L. et al. Highly nonlinear BiOBr nanoflakes for hybrid integrated photonics. APL Photonics Vol. 4, 090802 (2019).

82. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Linnan Jia, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David
J. Moss, "Enhanced supercontinuum generated in SiN waveguides coated with GO films", Advanced Materials Technologies 8 (1) 2201796 (2023). DOI:10.1002/admt.202201796.

83. Yuning Zhang, Jiayang Wu, Linnan Jia, Yang Qu, Baohua Jia, and David J. Moss, "Graphene oxide for nonlinear integrated photonics", Laser and Photonics Reviews 17 2200512 (2023). DOI:10.1002/lpor.202200512.

84. Jiayang Wu, H.Lin, David J. Moss, T.K. Loh, Baohua Jia, "Graphene oxide for electronics, photonics, and optoelectronics", Nature Reviews Chemistry 7 (3) 162–183 (2023). doi.org/10.1038/s41570-022-00458-7.

85. Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Linnan Jia, Baohua Jia, and David J. Moss, "Photo thermal tuning in GO-coated integrated waveguides", Micromachines Vol. 13 1194 (2022). doi.org/10.3390/mi13081194

86. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Houssein El Dirani, Romain Crochemore, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Enhanced self-phase modulation in silicon nitride waveguides integrated with 2D graphene oxide films", IEEE Journal of Selected Topics in Quantum Electronics Vol. 29 (1) 5100413 (2023). DOI: 10.1109/JSTQE.2022.3177385

87. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Enhanced spectral broadening of femtosecond optical pulses in silicon nanowires integrated with 2D graphene oxide films", Micromachines Vol. 13 756 (2022). DOI:10.3390/mi13050756.

88. Jiayang Wu, Yuning Zhang, Junkai Hu, Yunyi Yang, Di Jin, Wenbo Liu, Duan Huang, Baohua Jia, David J. Moss, "Novel functionality with 2D graphene oxide films integrated on silicon photonic chips", Advanced Materials (2024).

89. Yuning Zhang, Jiayang Wu, Linnan Jia, Di Jin, Baohua Jia, Xiaoyong Hu, David Moss, Qihuang Gong, "Advanced optical polarizers based on 2D materials", npj Nanophotonics (2024).

90. Junkai Hu, Jiayang Wu, Wenbo Liu, Di Jin, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Duan Huang, Baohua Jia, and David J. Moss, "2D graphene oxide: a versatile thermo-optic material", Advanced Functional Materials (2024).

91. Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Linnan Jia, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Optical parametric amplifiers based on silicon nitride waveguides integrated with 2D graphene oxide films", Light: Advanced Manufacturing 4 39 (2023). https://doi.org/10.37188/lam.2023.039.

92. Di Jin, Wenbo Liu, Linnan Jia, Junkai Hu, Duan Huang, Jiayang Wu, Baohua Jia, and David J. Moss, "Strong and layer-dependent nonlinear optical absorption in 2D layered MXene films", Small Science (2024).

93. Linnan Jia, Jiayang Wu, Yuning Zhang, Yang Qu, Baohua Jia, Zhigang Chen, and David J. Moss, "Fabrication Technologies for the On-Chip Integration of 2D Materials", Small: Methods Vol. 6, 2101435 (2022). DOI:10.1002/smtd.202101435.

94. Yuning Zhang, Jiayang Wu, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Design and optimization of four-wave mixing in microring resonators integrated with 2D graphene oxide films", Journal of Lightwave Technology Vol. 39 (20) 6553-6562 (2021). DOI:10.1109/JLT.2021.3101292.
J. Moss, "Enhanced supercontinuum generated in SiN waveguides coated with GO films", Advanced Materials Technologies 8 (1) 2201796 (2023). DOI:10.1002/admt.202201796.

83. Yuning Zhang, Jiayang Wu, Linnan Jia, Yang Qu, Baohua Jia, and David J. Moss, "Graphene oxide for nonlinear integrated photonics", Laser and Photonics Reviews 17 2200512 (2023). DOI:10.1002/lpor.202200512.

84. Jiayang Wu, H.Lin, David J. Moss, T.K. Loh, Baohua Jia, "Graphene oxide for electronics, photonics, and optoelectronics", Nature Reviews Chemistry 7 (3) 162–183 (2023). doi.org/10.1038/s41570-022-00458-7.

85. Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Linnan Jia, Baohua Jia, and David J. Moss, "Photo thermal tuning in GO-coated integrated waveguides", Micromachines Vol. 13 1194 (2022). doi.org/10.3390/mi13081194

86. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Houssein El Dirani, Romain Crochemore, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Enhanced self-phase modulation in silicon nitride waveguides integrated with 2D graphene oxide films", IEEE Journal of Selected Topics in Quantum Electronics Vol. 29 (1) 5100413 (2023). DOI: 10.1109/JSTQE.2022.3177385

87. Yuning Zhang, Jiayang Wu, Yunyi Yang, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Enhanced spectral broadening of femtosecond optical pulses in silicon nanowires integrated with 2D graphene oxide films", Micromachines Vol. 13 756 (2022). DOI:10.3390/mi13050756.

88. Jiayang Wu, Yuning Zhang, Junkai Hu, Yunyi Yang, Di Jin, Wenbo Liu, Duan Huang, Baohua Jia, David J. Moss, "Novel functionality with 2D graphene oxide films integrated on silicon photonic chips", Advanced Materials (2024).

89. Yuning Zhang, Jiayang Wu, Linnan Jia, Di Jin, Baohua Jia, Xiaoyong Hu, David Moss, Qihuang Gong, "Advanced optical polarizers based on 2D materials", npj Nanophotonics (2024).

90. Junkai Hu, Jiayang Wu, Wenbo Liu, Di Jin, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Duan Huang, Baohua Jia, and David J. Moss, "2D graphene oxide: a versatile thermo-optic material", Advanced Functional Materials (2024).

91. Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Linnan Jia, Houssein El Dirani, Sébastien Kerdiles, Corrado Sciancalepore, Pierre Demongodin, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Optical parametric amplifiers based on silicon nitride waveguides integrated with 2D graphene oxide films", Light: Advanced Manufacturing 4 39 (2023). https://doi.org/10.37188/lam.2023.039.

92. Di Jin, Wenbo Liu, Linnan Jia, Junkai Hu, Duan Huang, Jiayang Wu, Baohua Jia, and David J. Moss, "Strong and layer-dependent nonlinear optical absorption in 2D layered MXene films", Small Science (2024).

93. Linnan Jia, Jiayang Wu, Yuning Zhang, Yang Qu, Baohua Jia, Zhigang Chen, and David J. Moss, "Fabrication Technologies for the On-Chip Integration of 2D Materials", Small: Methods Vol. 6, 2101435 (2022). DOI:10.1002/smtd.202101435.

94. Yuning Zhang, Jiayang Wu, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Design and optimization of four-wave mixing in microring resonators integrated with 2D graphene oxide films", Journal of Lightwave Technology Vol. 39 (20) 6553-6562 (2021). DOI:10.1109/JLT.2021.3101292.
95. Yuning Zhang, Jiayang Wu, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Optimizing the Kerr nonlinear optical performance of silicon waveguides integrated with 2D graphene oxide films", Journal of Lightwave Technology Vol. 39 (14) 4671-4683 (2021). DOI: 10.1109/JLT.2021.3069733.

96. Yang Qu, Jiayang Wu, Yuning Zhang, Yao Liang, Baohua Jia, and David J. Moss, "Analysis of four-wave mixing in silicon nitride waveguides integrated with 2D layered graphene oxide films", Journal of Lightwave Technology Vol. 39 (9) 2902-2910 (2021). DOI: 10.1109/JLT.2021.3059721.

97. Jiayang Wu, Linnan Jia, Yuning Zhang, Yang Qu, Baohua Jia, and David J. Moss, "Graphene oxide: versatile films for flat optics to nonlinear photonic chips", Advanced Materials Vol. 33 (3) 2006415, pp.1-29 (2021). DOI:10.1002/adma.202006415.

98. Y. Qu, J. Wu, Y. Zhang, L. Jia, Y. Yang, X. Xu, S. T. Chu, B. E. Little, R. Morandotti, B. Jia, and D. J. Moss, "Graphene oxide for enhanced optical nonlinear performance in CMOS compatible integrated devices", Paper No. 11688-30, PW21O-OE109-36, 2D Photonic Materials and Devices IV, SPIE Photonics West, San Francisco CA March 6-11 (2021). doi.org/10.1117/12.2583978

99. Yang Qu, Jiayang Wu, Yunyi Yang, Yuning Zhang, Yao Liang, Houssein El Dirani, Romain Crochemore, Pierre Demongodin, Corrado Sciancalepore, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Enhanced nonlinear four-wave mixing in silicon nitride waveguides integrated with 2D layered graphene oxide films", Advanced Optical Materials vol. 8 (21) 2001048 (2020). DOI: 10.1002/adom.202001048. arXiv:2006.14944.

100. Yuning Zhang, Yang Qu, Jiayang Wu, Linnan Jia, Yunyi Yang, Xingyuan Xu, Baohua Jia, and David J. Moss, "Enhanced Kerr nonlinearity and nonlinear figure of merit in silicon nanowires integrated with 2D graphene oxide films", ACS Applied Materials and Interfaces vol. 12 (29) 33094-33103 June 29 (2020). DOI:10.1021/acsami.0c07852

101. Jiayang Wu, Yunyi Yang, Yang Qu, Yuning Zhang, Linnan Jia, Xingyuan Xu, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Enhanced nonlinear four-wave mixing in microring resonators integrated with layered graphene oxide films", Small vol. 16 (16) 1906563 (2020). DOI: 10.1002/smll.201906563

102. Jiayang Wu, Yunyi Yang, Yang Qu, Xingyuan Xu, Yao Liang, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Graphene oxide waveguide polarizers and polarization selective micro-ring resonators", Paper 11282-29, SPIE Photonics West, San Francisco, CA, 4-7 February (2020). doi: 10.1117/12.2544584

103. Jiayang Wu, Yunyi Yang, Yang Qu, Xingyuan Xu, Yao Liang, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Graphene oxide waveguide polarizers and polarization selective micro-ring resonators", Laser and Photonics Reviews vol. 13 (9) 1900056 (2019). DOI:10.1002/lpor.201900056.

104. Yunyi Yang, Jiayang Wu, Xingyuan Xu, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Enhanced four-wave mixing in graphene oxide coated waveguides", Applied Physics Letters Photonics vol. 3 120803 (2018). doi: 10.1063/1.5045509.

105. Linnan Jia, Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Baohua Jia, and David J. Moss, "Third-order optical nonlinearities of 2D materials at telecommunications wavelengths", Micromachines (MDPI), 14, 307 (2023). https://doi.org/10.3390/mi14020307.

106. Linnan Jia, Dandan Cui, Jiayang Wu, Haifeng Feng, Tieshan Yang, Yunyi Yang, Yi Du, Weichang Hao, Baohua Jia, David J. Moss, "BiOBr nanoflakes with strong nonlinear optical properties towards
95. Yuning Zhang, Jiayang Wu, Yang Qu, Linnan Jia, Baohua Jia, and David J. Moss, "Optimizing the Kerr nonlinear optical performance of silicon waveguides integrated with 2D graphene oxide films", Journal of Lightwave Technology Vol. 39 (14) 4671-4683 (2021). DOI: 10.1109/JLT.2021.3069733.

96. Yang Qu, Jiayang Wu, Yuning Zhang, Yao Liang, Baohua Jia, and David J. Moss, "Analysis of four-wave mixing in silicon nitride waveguides integrated with 2D layered graphene oxide films", Journal of Lightwave Technology Vol. 39 (9) 2902-2910 (2021). DOI: 10.1109/JLT.2021.3059721.

97. Jiayang Wu, Linnan Jia, Yuning Zhang, Yang Qu, Baohua Jia, and David J. Moss, "Graphene oxide: versatile films for flat optics to nonlinear photonic chips", Advanced Materials Vol. 33 (3) 2006415, pp.1-29 (2021). DOI:10.1002/adma.202006415.

98. Y. Qu, J. Wu, Y. Zhang, L. Jia, Y. Yang, X. Xu, S. T. Chu, B. E. Little, R. Morandotti, B. Jia, and D. J. Moss, "Graphene oxide for enhanced optical nonlinear performance in CMOS compatible integrated devices", Paper No. 11688-30, PW21O-OE109-36, 2D Photonic Materials and Devices IV, SPIE Photonics West, San Francisco CA March 6-11 (2021). doi.org/10.1117/12.2583978

99. Yang Qu, Jiayang Wu, Yunyi Yang, Yuning Zhang, Yao Liang, Houssein El Dirani, Romain Crochemore, Pierre Demongodin, Corrado Sciancalepore, Christian Grillet, Christelle Monat, Baohua Jia, and David J. Moss, "Enhanced nonlinear four-wave mixing in silicon nitride waveguides integrated with 2D layered graphene oxide films", Advanced Optical Materials vol. 8 (21) 2001048 (2020). DOI: 10.1002/adom.202001048. arXiv:2006.14944.

100. Yuning Zhang, Yang Qu, Jiayang Wu, Linnan Jia, Yunyi Yang, Xingyuan Xu, Baohua Jia, and David J. Moss, "Enhanced Kerr nonlinearity and nonlinear figure of merit in silicon nanowires integrated with 2D graphene oxide films", ACS Applied Materials and Interfaces vol. 12 (29) 33094-33103 June 29 (2020). DOI:10.1021/acsami.0c07852

101. Jiayang Wu, Yunyi Yang, Yang Qu, Yuning Zhang, Linnan Jia, Xingyuan Xu, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Enhanced nonlinear four-wave mixing in microring resonators integrated with layered graphene oxide films", Small vol. 16 (16) 1906563 (2020). DOI: 10.1002/smll.201906563

102. Jiayang Wu, Yunyi Yang, Yang Qu, Xingyuan Xu, Yao Liang, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Graphene oxide waveguide polarizers and polarization selective micro-ring resonators", Paper 11282-29, SPIE Photonics West, San Francisco, CA, 4-7 February (2020). doi: 10.1117/12.2544584

103. Jiayang Wu, Yunyi Yang, Yang Qu, Xingyuan Xu, Yao Liang, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Graphene oxide waveguide polarizers and polarization selective micro-ring resonators", Laser and Photonics Reviews vol. 13 (9) 1900056 (2019). DOI:10.1002/lpor.201900056.

104. Yunyi Yang, Jiayang Wu, Xingyuan Xu, Sai T. Chu, Brent E. Little, Roberto Morandotti, Baohua Jia, and David J. Moss, "Enhanced four-wave mixing in graphene oxide coated waveguides", Applied Physics Letters Photonics vol. 3 120803 (2018). doi: 10.1063/1.5045509.

105. Linnan Jia, Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Baohua Jia, and David J. Moss, "Third-order optical nonlinearities of 2D materials at telecommunications wavelengths", Micromachines (MDPI), 14, 307 (2023). https://doi.org/10.3390/mi14020307.

106. Linnan Jia, Dandan Cui, Jiayang Wu, Haifeng Feng, Tieshan Yang, Yunyi Yang, Yi Du, Weichang Hao, Baohua Jia, David J. Moss, "BiOBr nanoflakes with strong nonlinear optical properties towards
hybrid integrated photonic devices", Applied Physics Letters Photonics vol. 4 090802 vol. (2019). DOI:
10.1063/1.5116621

107. Linnan Jia, Jiayang Wu, Yunyi Yang, Yi Du, Baohua Jia, David J. Moss, "Large Third-Order Optical Kerr Nonlinearity in Nanometer-Thick PdSe2 2D Dichalcogenide Films: Implications for Nonlinear Photonic Devices", ACS Applied Nano Materials vol. 3 (7) 6876-6883 (2020).
DOI:10.1021/acsanm.0c01239.

108. Moss, D. J., Morandotti, R., Gaeta, A. L. & Lipson, M. New CMOS compatible platforms based on silicon nitride and Hydex for nonlinear optics. Nat. Photonics Vol. 7, 597-607 (2013).

109. L. Razzari, et al., "CMOS-compatible integrated optical hyper-parametric oscillator," Nature Photonics, vol. 4, no. 1, pp. 41-45, 2010.

110. A. Pasquazi, et al., "Sub-picosecond phase-sensitive optical pulse characterization on a chip", Nature Photonics, vol. 5, no. 10, pp. 618-623 (2011).

111. M Ferrera et al., "On-Chip ultra-fast 1st and 2nd order CMOS compatible all-optical integration", Optics Express vol. 19 (23), 23153-23161 (2011).

112. Bao, C., et al., Direct soliton generation in microresonators, Opt. Lett, 42, 2519 (2017).

113. M.Ferrera et al., "CMOS compatible integrated all-optical RF spectrum analyzer", Optics Express, vol. 22, no. 18, 21488 - 21498 (2014).

114. M. Kues, et al., "Passively modelocked laser with an ultra-narrow spectral width", Nature Photonics, vol. 11, no. 3, pp. 159, 2017.

115. M. Ferrera, et al., "Low-power continuous-wave nonlinear optics in doped silica glass integrated waveguide structures," Nature Photonics, vol. 2, no. 12, pp. 737-740, 2008.

116. M.Ferrera et al. "On-Chip ultra-fast 1st and 2nd order CMOS compatible all-optical integration", Opt. Express, vol. 19, (23)pp. 23153-23161 (2011).

117. D. Duchesne, M. Peccianti, M. R. E. Lamont, et al., "Supercontinuum generation in a high index doped silica glass spiral waveguide," Optics Express, vol. 18, no. 2, pp. 923-930, 2010.

118. H Bao, L Olivieri, M Rowley, ST Chu, BE Little, R Morandotti, DJ Moss, ... "Turing patterns in a fiber laser with a nested microresonator: Robust and controllable microcomb generation", Physical Review Research vol. 2 (2), 023395 (2020).

119. M. Ferrera, et al., "On-chip CMOS-compatible all-optical integrator", Nature Communications, vol. 1, Article 29, 2010.

120. A. Pasquazi, et al., "All-optical wavelength conversion in an integrated ring resonator," Optics Express, vol. 18, no. 4, pp. 3858-3863, 2010.

121. A.Pasquazi, Y. Park, J. Azana, et al., "Efficient wavelength conversion and net parametric gain via Four Wave Mixing in a high index doped silica waveguide," Optics Express, vol. 18, no. 8, pp. 7634-7641, 2010.

122. Peccianti, M. Ferrera, L. Razzari, et al., "Subpicosecond optical pulse compression via an integrated nonlinear chirper," Optics Express, vol. 18, no. 8, pp. 7625-7633, 2010.

123. M Ferrera, Y Park, L Razzari, BE Little, ST Chu, R Morandotti, DJ Moss, ... et al., "All-optical 1st and 2nd order integration on a chip", Optics Express vol. 19 (23), 23153-23161 (2011).

124. M. Ferrera et al., "Low Power CW Parametric Mixing in a Low Dispersion High Index Doped Silica Glass Micro-Ring Resonator with Q-factor > 1 Million", Optics Express, vol.17, no. 16, pp. 14098-14103 (2009).
hybrid integrated photonic devices", Applied Physics Letters Photonics vol. 4 090802 vol. (2019). DOI:
10.1063/1.5116621

107. Linnan Jia, Jiayang Wu, Yunyi Yang, Yi Du, Baohua Jia, David J. Moss, "Large Third-Order Optical Kerr Nonlinearity in Nanometer-Thick PdSe2 2D Dichalcogenide Films: Implications for Nonlinear Photonic Devices", ACS Applied Nano Materials vol. 3 (7) 6876-6883 (2020).
DOI:10.1021/acsanm.0c01239

108. Moss, D. J., Morandotti, R., Gaeta, A. L. & Lipson, M. New CMOS compatible platforms based on silicon nitride and Hydex for nonlinear optics. Nat. Photonics Vol. 7, 597-607 (2013).

109. L. Razzari, et al., "CMOS-compatible integrated optical hyper-parametric oscillator," Nature Photonics, vol. 4, no. 1, pp. 41-45, 2010.

110. A. Pasquazi, et al., "Sub-picosecond phase-sensitive optical pulse characterization on a chip", Nature Photonics, vol. 5, no. 10, pp. 618-623 (2011).

111. M Ferrera et al., "On-Chip ultra-fast 1st and 2nd order CMOS compatible all-optical integration", Optics Express vol. 19 (23), 23153-23161 (2011).

112. Bao, C., et al., Direct soliton generation in microresonators, Opt. Lett, 42, 2519 (2017).

113. M.Ferrera et al., "CMOS compatible integrated all-optical RF spectrum analyzer", Optics Express, vol. 22, no. 18, 21488 - 21498 (2014).

114. M. Kues, et al., "Passively modelocked laser with an ultra-narrow spectral width", Nature Photonics, vol. 11, no. 3, pp. 159, 2017.

115. M. Ferrera, et al., "Low-power continuous-wave nonlinear optics in doped silica glass integrated waveguide structures," Nature Photonics, vol. 2, no. 12, pp. 737-740, 2008.

116. M.Ferrera et al. "On-Chip ultra-fast 1st and 2nd order CMOS compatible all-optical integration", Opt. Express, vol. 19, (23)pp. 23153-23161 (2011).

117. D. Duchesne, M. Peccianti, M. R. E. Lamont, et al., "Supercontinuum generation in a high index doped silica glass spiral waveguide," Optics Express, vol. 18, no. 2, pp. 923-930, 2010.

118. H Bao, L Olivieri, M Rowley, ST Chu, BE Little, R Morandotti, DJ Moss, ... "Turing patterns in a fiber laser with a nested microresonator: Robust and controllable microcomb generation", Physical Review Research vol. 2 (2), 023395 (2020).

119. M. Ferrera, et al., "On-chip CMOS-compatible all-optical integrator", Nature Communications, vol. 1, Article 29, 2010.

120. A. Pasquazi, et al., "All-optical wavelength conversion in an integrated ring resonator," Optics Express, vol. 18, no. 4, pp. 3858-3863, 2010.

121. A.Pasquazi, Y. Park, J. Azana, et al., "Efficient wavelength conversion and net parametric gain via Four Wave Mixing in a high index doped silica waveguide," Optics Express, vol. 18, no. 8, pp. 7634-7641, 2010.

122. Peccianti, M. Ferrera, L. Razzari, et al., "Subpicosecond optical pulse compression via an integrated nonlinear chirper," Optics Express, vol. 18, no. 8, pp. 7625-7633, 2010.

123. M Ferrera, Y Park, L Razzari, BE Little, ST Chu, R Morandotti, DJ Moss, ... et al., "All-optical 1st and 2nd order integration on a chip", Optics Express vol. 19 (23), 23153-23161 (2011).

124. M. Ferrera et al., "Low Power CW Parametric Mixing in a Low Dispersion High Index Doped Silica Glass Micro-Ring Resonator with Q-factor > 1 Million", Optics Express, vol.17, no. 16, pp. 14098-14103 (2009).
125. M. Peccianti, et al., “Demonstration of an ultrafast nonlinear microcavity modelocked laser”, Nature Communications, vol. 3, pp. 765, 2012.

126. A.Pasquazi, et al., “Self-locked optical parametric oscillation in a CMOS compatible microring resonator: a route to robust optical frequency comb generation on a chip,” Optics Express, vol. 21, no. 11, pp. 13333-13341, 2013.

127. A.Pasquazi, et al., “Stable, dual mode, high repetition rate mode-locked laser based on a microring resonator,” Optics Express, vol. 20, no. 24, pp. 27355-27362, 2012.

128. Pasquazi, A. et al. Micro-combs: a novel generation of optical sources. Physics Reports 729, 1-81 (2018).

129. Yang Sun, Jiayang Wu, Mengxi Tan, Xingyuan Xu, Yang Li, Roberto Morandotti, Arnan Mitchell, and David J. Moss, “Applications of optical micro-combs”, Advances in Optics and Photonics 15 (1) 86-175 (2023). https://doi.org/10.1364/AOP.470264.

130. H. Bao, et al., Laser cavity-soliton microcombs, Nature Photonics, vol. 13, no. 6, pp. 384-389, Jun. 2019.

131. Antonio Cutrona, Maxwell Rowley, Debayan Das, Luana Olivieri, Luke Peters, Sai T. Chu, Brent L. Little, Roberto Morandotti, David J. Moss, Juan Sebastian Totero Gongora, Marco Peccianti, Alessia Pasquazi, “High Conversion Efficiency in Laser Cavity-Soliton Microcombs”, Optics Express Vol. 30, Issue 22, pp. 39816-39825 (2022). https://doi.org/10.1364/OE.470376.

132. M. Rowley, P. Hanzard, A. Cutrona, H. Bao, S. Chu, B. Little, R. Morandotti, D. J. Moss, G. Oppo, J. Gongora, M. Peccianti and A. Pasquazi, “Self-emergence of robust solitons in a micro-cavity”, Nature vol. 608 (7922) 303–309 (2022).

133. A. Cutrona, M. Rowley, A. Bendahmane, V. Cecconi, L. Peters, L. Olivieri, B. E. Little, S. T. Chu, S. Stivala, R. Morandotti, D. J. Moss, J. S. Totero-Gongora, M. Peccianti, A. Pasquazi, “Nonlocal bonding of a soliton and a blue-detuned state in a microcomb laser”, Nature Communications Physics 6 Article 259 (2023). https://doi.org/10.1038/s42005-023-01372-0.

134. Aadhi A. Rahim, Imtiaz Alamgir, Luigi Di Lauro, Bennet Fischer, Nicolas Perron, Pavel Dmitriev, Celine Mazoukh, Piotr Roztocki, Cristina Rimoldi, Mario Chemnitz, Armaghan Eshaghi, Evgeny A. Viktorov, Anton V. Kovalev, Brent E. Little, Sai T. Chu, David J. Moss, and Roberto Morandotti, “Mode-locked laser with multiple timescales in a microresonator-based nested cavity”, APL Photonics 9 031302 (2024). DOI:10.1063/5.0174697.

135. A. Cutrona, M. Rowley, A. Bendahmane, V. Cecconi, L. Peters, L. Olivieri, B. E. Little, S. T. Chu, S. Stivala, R. Morandotti, D. J. Moss, J. S. Totero-Gongora, M. Peccianti, A. Pasquazi, “Stability Properties of Laser Cavity-Solitons for Metrological Applications”, Applied Physics Letters vol. 122 (12) 121104 (2023); doi: 10.1063/5.0134147.

136. X. Xu, J. Wu, M. Shoeiby, T. G. Nguyen, S. T. Chu, B. E. Little, R. Morandotti, A. Mitchell, and D. J. Moss, “Reconfigurable broadband microwave photonic intensity differentiator based on an integrated optical frequency comb source,” APL Photonics, vol. 2, no. 9, 096104, Sep. 2017.

137. Xu, X., et al., Photonic microwave true time delays for phased array antennas using a 49 GHz FSR integrated micro-comb source, Photonics Research, vol. 6, B30-B36 (2018).

138. X. Xu, M. Tan, J. Wu, R. Morandotti, A. Mitchell, and D. J. Moss, “Microcomb-based photonic RF signal processing”, IEEE Photonics Technology Letters, vol. 31 no. 23 1854-1857, 2019.
125. M. Peccianti, et al., “Demonstration of an ultrafast nonlinear microcavity modelocked laser”, Nature Communications, vol. 3, pp. 765, 2012.

126. A.Pasquazi, et al., “Self-locked optical parametric oscillation in a CMOS compatible microring resonator: a route to robust optical frequency comb generation on a chip,” Optics Express, vol. 21, no. 11, pp. 13333-13341, 2013.

127. A.Pasquazi, et al., “Stable, dual mode, high repetition rate mode-locked laser based on a microring resonator,” Optics Express, vol. 20, no. 24, pp. 27355-27362, 2012.

128. Pasquazi, A. et al. Micro-combs: a novel generation of optical sources. Physics Reports 729, 1-81 (2018).

129. Yang Sun, Jiayang Wu, Mengxi Tan, Xingyuan Xu, Yang Li, Roberto Morandotti, Arnan Mitchell, and David J. Moss, “Applications of optical micro-combs”, Advances in Optics and Photonics 15 (1) 86-175 (2023). https://doi.org/10.1364/AOP.470264.

130. H. Bao, et al., Laser cavity-soliton microcombs, Nature Photonics, vol. 13, no. 6, pp. 384-389, Jun. 2019.

131. Antonio Cutrona, Maxwell Rowley, Debayan Das, Luana Olivieri, Luke Peters, Sai T. Chu, Brent L. Little, Roberto Morandotti, David J. Moss, Juan Sebastian Totero Gongora, Marco Peccianti, Alessia Pasquazi, “High Conversion Efficiency in Laser Cavity-Soliton Microcombs”, Optics Express Vol. 30, Issue 22, pp. 39816-39825 (2022). https://doi.org/10.1364/OE.470376.

132. M. Rowley, P. Hanzard, A. Cutrona, H. Bao, S. Chu, B. Little, R. Morandotti, D. J. Moss, G. Oppo, J. Gongora, M. Peccianti and A. Pasquazi, “Self-emergence of robust solitons in a micro-cavity”, Nature vol. 608 (7922) 303–309 (2022).

133. A. Cutrona, M. Rowley, A. Bendahmane, V. Cecconi, L. Peters, L. Olivieri, B. E. Little, S. T. Chu, S. Stivala, R. Morandotti, D. J. Moss, J. S. Totero-Gongora, M. Peccianti, A. Pasquazi, “Nonlocal bonding of a soliton and a blue-detuned state in a microcomb laser”, Nature Communications Physics 6 Article 259 (2023). https://doi.org/10.1038/s42005-023-01372-0.

134. Aadhi A. Rahim, Imtiaz Alamgir, Luigi Di Lauro, Bennet Fischer, Nicolas Perron, Pavel Dmitriev, Celine Mazoukh, Piotr Roztocki, Cristina Rimoldi, Mario Chemnitz, Armaghan Eshaghi, Evgeny A. Viktorov, Anton V. Kovalev, Brent E. Little, Sai T. Chu, David J. Moss, and Roberto Morandotti, “Mode-locked laser with multiple timescales in a microresonator-based nested cavity”, APL Photonics 9 031302 (2024). DOI:10.1063/5.0174697.

135. A. Cutrona, M. Rowley, A. Bendahmane, V. Cecconi, L. Peters, L. Olivieri, B. E. Little, S. T. Chu, S. Stivala, R. Morandotti, D. J. Moss, J. S. Totero-Gongora, M. Peccianti, A. Pasquazi, “Stability Properties of Laser Cavity-Solitons for Metrological Applications”, Applied Physics Letters vol. 122 (12) 121104 (2023); doi: 10.1063/5.0134147.

136. X. Xu, J. Wu, M. Shoeiby, T. G. Nguyen, S. T. Chu, B. E. Little, R. Morandotti, A. Mitchell, and D. J. Moss, “Reconfigurable broadband microwave photonic intensity differentiator based on an integrated optical frequency comb source,” APL Photonics, vol. 2, no. 9, 096104, Sep. 2017.

137. Xu, X., et al., Photonic microwave true time delays for phased array antennas using a 49 GHz FSR integrated micro-comb source, Photonics Research, vol. 6, B30-B36 (2018).

138. X. Xu, M. Tan, J. Wu, R. Morandotti, A. Mitchell, and D. J. Moss, “Microcomb-based photonic RF signal processing”, IEEE Photonics Technology Letters, vol. 31 no. 23 1854-1857, 2019.
139. Xu, et al., "Advanced adaptive photonic RF filters with 80 taps based on an integrated optical micro-comb source," Journal of Lightwave Technology, vol. 37, no. 4, pp. 1288-1295 (2019).

140. X. Xu, et al., "Photonic RF and microwave integrator with soliton crystal microcombs", IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 67, no. 12, pp. 3582-3586, 2020. DOI:10.1109/TCSII.2020.2995682.

141. X. Xu, et al., "High performance RF filters via bandwidth scaling with Kerr micro-combs," APL Photonics, vol. 4 (2) 026102. 2019.

142. M. Tan, et al., "Microwave and RF photonic fractional Hilbert transformer based on a 50 GHz Kerr micro-comb", Journal of Lightwave Technology, vol. 37, no. 24, pp. 6097-6104, 2019.

143. M. Tan, et al., "RF and microwave fractional differentiator based on photonics", IEEE Transactions on Circuits and Systems: Express Briefs, vol. 67, no.11, pp. 2767-2771, 2020. DOI:10.1109/TCSII.2020.2965158.

144. M. Tan, et al., "Photonic RF arbitrary waveform generator based on a soliton crystal micro-comb source", Journal of Lightwave Technology, vol. 38, no. 22, pp. 6221-6226 (2020). DOI: 10.1109/JLT.2020.3009655.

145. M. Tan, X. Xu, J. Wu, R. Morandotti, A. Mitchell, and D. J. Moss, "RF and microwave high bandwidth signal processing based on Kerr Micro-combs", Advances in Physics X, VOL. 6, NO. 1, 1838946 (2021). DOI:10.1080/23746149.2020.1838946.

146. 123. X. Xu, et al., "Advanced RF and microwave functions based on an integrated optical frequency comb source," Opt. Express, vol. 26 (3) 2569 (2018).

147. M. Tan, X. Xu, J. Wu, B. Corcoran, A. Boes, T. G. Nguyen, S. T. Chu, B. E. Little, R. Morandotti, A. Lowery, A. Mitchell, and D. J. Moss, ""Highly Versatile Broadband RF Photonic Fractional Hilbert Transformer Based on a Kerr Soliton Crystal Microcomb", Journal of Lightwave Technology vol. 39 (24) 7581-7587 (2021).

148. Wu, J. et al. RF Photonics: An Optical Microcombs' Perspective. IEEE Journal of Selected Topics in Quantum Electronics Vol. 24, 6101020, 1-20 (2018).

149. T. G. Nguyen et al., "Integrated frequency comb source-based Hilbert transformer for wideband microwave photonic phase analysis," Opt. Express, vol. 23, no. 17, pp. 22087-22097, Aug. 2015.

150. X. Xu, et al., "Broadband RF channelizer based on an integrated optical frequency Kerr comb source," Journal of Lightwave Technology, vol. 36, no. 19, pp. 4519-4526, 2018.

151. X. Xu, et al., "Continuously tunable orthogonally polarized RF optical single sideband generator based on micro-ring resonators," Journal of Optics, vol. 20, no. 11, 115701. 2018.

152. X. Xu, et al., "Orthogonally polarized RF optical single sideband generation and dual-channel equalization based on an integrated microring resonator," Journal of Lightwave Technology, vol. 36, no. 20, pp. 4808-4818. 2018.

153. X. Xu, et al., "Photonic RF phase-encoded signal generation with a microcomb source", J. Lightwave Technology, vol. 38, no. 7, 1722-1727, 2020.

154. X. Xu, et al., Broadband microwave frequency conversion based on an integrated optical micro-comb source", Journal of Lightwave Technology, vol. 38 no. 2, pp. 332-338, 2020.

155. M. Tan, et al., "Photonic RF and microwave filters based on 49GHz and 200GHz Kerr microcombs", Optics Comm. vol. 465, 125563, Feb. 22. 2020.
139. Xu, et al., "Advanced adaptive photonic RF filters with 80 taps based on an integrated optical micro-comb source," Journal of Lightwave Technology, vol. 37, no. 4, pp. 1288-1295 (2019).

140. X. Xu, et al., "Photonic RF and microwave integrator with soliton crystal microcombs", IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 67, no. 12, pp. 3582-3586, 2020. DOI:10.1109/TCSII.2020.2995682.

141. X. Xu, et al., "High performance RF filters via bandwidth scaling with Kerr micro-combs," APL Photonics, vol. 4 (2) 026102. 2019.

142. M. Tan, et al., "Microwave and RF photonic fractional Hilbert transformer based on a 50 GHz Kerr micro-comb", Journal of Lightwave Technology, vol. 37, no. 24, pp. 6097-6104, 2019.

143. M. Tan, et al., "RF and microwave fractional differentiator based on photonics", IEEE Transactions on Circuits and Systems: Express Briefs, vol. 67, no.11, pp. 2767-2771, 2020. DOI:10.1109/TCSII.2020.2965158.

144. M. Tan, et al., "Photonic RF arbitrary waveform generator based on a soliton crystal micro-comb source", Journal of Lightwave Technology, vol. 38, no. 22, pp. 6221-6226 (2020). DOI: 10.1109/JLT.2020.3009655.

145. M. Tan, X. Xu, J. Wu, R. Morandotti, A. Mitchell, and D. J. Moss, "RF and microwave high bandwidth signal processing based on Kerr Micro-combs", Advances in Physics X, VOL. 6, NO. 1, 1838946 (2021). DOI:10.1080/23746149.2020.1838946.

146. 123. X. Xu, et al., "Advanced RF and microwave functions based on an integrated optical frequency comb source," Opt. Express, vol. 26 (3) 2569 (2018).

147. M. Tan, X. Xu, J. Wu, B. Corcoran, A. Boes, T. G. Nguyen, S. T. Chu, B. E. Little, R. Morandotti, A. Lowery, A. Mitchell, and D. J. Moss, ""Highly Versatile Broadband RF Photonic Fractional Hilbert Transformer Based on a Kerr Soliton Crystal Microcomb", Journal of Lightwave Technology vol. 39 (24) 7581-7587 (2021).

148. Wu, J. et al. RF Photonics: An Optical Microcombs' Perspective. IEEE Journal of Selected Topics in Quantum Electronics Vol. 24, 6101020, 1-20 (2018).

149. T. G. Nguyen et al., "Integrated frequency comb source-based Hilbert transformer for wideband microwave photonic phase analysis," Opt. Express, vol. 23, no. 17, pp. 22087-22097, Aug. 2015.

150. X. Xu, et al., "Broadband RF channelizer based on an integrated optical frequency Kerr comb source," Journal of Lightwave Technology, vol. 36, no. 19, pp. 4519-4526, 2018.

151. X. Xu, et al., "Continuously tunable orthogonally polarized RF optical single sideband generator based on micro-ring resonators," Journal of Optics, vol. 20, no. 11, 115701. 2018.

152. X. Xu, et al., "Orthogonally polarized RF optical single sideband generation and dual-channel equalization based on an integrated microring resonator," Journal of Lightwave Technology, vol. 36, no. 20, pp. 4808-4818. 2018.

153. X. Xu, et al., "Photonic RF phase-encoded signal generation with a microcomb source", J. Lightwave Technology, vol. 38, no. 7, 1722-1727, 2020.

154. X. Xu, et al., Broadband microwave frequency conversion based on an integrated optical micro-comb source", Journal of Lightwave Technology, vol. 38 no. 2, pp. 332-338, 2020.

155. M. Tan, et al., "Photonic RF and microwave filters based on 49GHz and 200GHz Kerr microcombs", Optics Comm. vol. 465, 125563, Feb. 22. 2020.
156. X. Xu, et al., "Broadband photonic RF channelizer with 90 channels based on a soliton crystal microcomb", Journal of Lightwave Technology, Vol. 38, no. 18, pp. 5116 – 5121 (2020). doi: 10.1109/JLT.2020.2997699.

157. M. Tan et al, "Orthogonally polarized Photonic Radio Frequency single sideband generation with integrated micro-ring resonators", IOP Journal of Semiconductors, Vol. 42 (4), 041305 (2021). DOI: 10.1088/1674-4926/42/4/041305.

158. Mengxi Tan, X. Xu, J. Wu, T. G. Nguyen, S. T. Chu, B. E. Little, R. Morandotti, A. Mitchell, and David J. Moss, "Photonic Radio Frequency Channelizers based on Kerr Optical Micro-combs", IOP Journal of Semiconductors Vol. 42 (4), 041302 (2021). DOI:10.1088/1674-4926/42/4/041302.

159. B. Corcoran, et al., "Ultra-dense optical data transmission over standard fiber with a single chip source", Nature Communications, vol. 11, Article:2568, 2020.

160. X. Xu et al, "Photonic perceptron based on a Kerr microcomb for scalable high speed optical neural networks", Laser and Photonics Reviews, vol. 14, no. 8, 2000070 (2020). DOI: 10.1002/lpor.202000070.

161. X. Xu, et al., "11 TOPs photonic convolutional accelerator for optical neural networks", Nature vol. 589, 44-51 (2021).

162. Xingyuan Xu, Weiwei Han, Mengxi Tan, Yang Sun, Yang Li, Jiayang Wu, Roberto Morandotti, Arnan Mitchell, Kun Xu, and David J. Moss, "Neuromorphic computing based on wavelength-division multiplexing", IEEE Journal of Selected Topics in Quantum Electronics 29 (2) 7400112 (2023). DOI:10.1109/JSTQE.2022.3203159.

163. Yunping Bai, Xingyuan Xu,1, Mengxi Tan, Yang Sun, Yang Li, Jiayang Wu, Roberto Morandotti, Arnan Mitchell, Kun Xu, and David J. Moss, "Photonic multiplexing techniques for neuromorphic computing", Nanophotonics vol. 12 (5): 795-817 (2023). DOI:10.1515/nanoph-2022-0485.

164. Chawaphon Prayoonyong, Andreas Boes, Xingyuan Xu, Mengxi Tan, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, David J. Moss, and Bill Corcoran, "Frequency comb distillation for optical superchannel transmission", Journal of Lightwave Technology vol. 39 (23) 7383-7392 (2021). DOI: 10.1109/JLT.2021.3116614.

165. Mengxi Tan, Xingyuan Xu, Jiayang Wu, Bill Corcoran, Andreas Boes, Thach G. Nguyen, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, and David J. Moss, "Integral order photonic RF signal processors based on a soliton crystal micro-comb source", IOP Journal of Optics vol. 23 (11) 125701 (2021). https://doi.org/10.1088/2040-8986/ac2eab

166. Yang Sun, Jiayang Wu, Yang Li, Xingyuan Xu, Guanghui Ren, Mengxi Tan, Sai Tak Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, and David J. Moss, "Optimizing the performance of microcomb based microwave photonic transversal signal processors", Journal of Lightwave Technology vol. 41 (23) pp 7223-7237 (2023). DOI: 10.1109/JLT.2023.3314526.

167. Mengxi Tan, Xingyuan Xu, Andreas Boes, Bill Corcoran, Thach G. Nguyen, Sai T. Chu, Brent E. Little, Roberto Morandotti, Jiayang Wu, Arnan Mitchell, and David J. Moss, "Photonic signal processor for real-time video image processing based on a Kerr microcomb", Communications Engineering vol. 2 94 (2023). DOI:10.1038/s44172-023-00135-7

168. Mengxi Tan, Xingyuan Xu, Jiayang Wu, Roberto Morandotti, Arnan Mitchell, and David J. Moss, "Photonic RF and microwave filters based on 49GHz and 200GHz Kerr microcombs", Optics
156. X. Xu, et al., "Broadband photonic RF channelizer with 90 channels based on a soliton crystal microcomb", Journal of Lightwave Technology, Vol. 38, no. 18, pp. 5116 – 5121 (2020). doi: 10.1109/JLT.2020.2997699.

157. M. Tan et al, "Orthogonally polarized Photonic Radio Frequency single sideband generation with integrated micro-ring resonators", IOP Journal of Semiconductors, Vol. 42 (4), 041305 (2021). DOI: 10.1088/1674-4926/42/4/041305.

158. Mengxi Tan, X. Xu, J. Wu, T. G. Nguyen, S. T. Chu, B. E. Little, R. Morandotti, A. Mitchell, and David J. Moss, "Photonic Radio Frequency Channelizers based on Kerr Optical Micro-combs", IOP Journal of Semiconductors Vol. 42 (4), 041302 (2021). DOI:10.1088/1674-4926/42/4/041302.

159. B. Corcoran, et al., "Ultra-dense optical data transmission over standard fiber with a single chip source", Nature Communications, vol. 11, Article:2568, 2020.

160. X. Xu et al, "Photonic perceptron based on a Kerr microcomb for scalable high speed optical neural networks", Laser and Photonics Reviews, vol. 14, no. 8, 2000070 (2020). DOI: 10.1002/lpor.202000070.

161. X. Xu, et al., "11 TOPs photonic convolutional accelerator for optical neural networks", Nature vol. 589, 44-51 (2021).

162. Xingyuan Xu, Weiwei Han, Mengxi Tan, Yang Sun, Yang Li, Jiayang Wu, Roberto Morandotti, Arnan Mitchell, Kun Xu, and David J. Moss, "Neuromorphic computing based on wavelength-division multiplexing", IEEE Journal of Selected Topics in Quantum Electronics 29 (2) 7400112 (2023). DOI:10.1109/JSTQE.2022.3203159.

163. Yunping Bai, Xingyuan Xu,1, Mengxi Tan, Yang Sun, Yang Li, Jiayang Wu, Roberto Morandotti, Arnan Mitchell, Kun Xu, and David J. Moss, "Photonic multiplexing techniques for neuromorphic computing", Nanophotonics vol. 12 (5): 795-817 (2023). DOI:10.1515/nanoph-2022-0485.

164. Chawaphon Prayoonyong, Andreas Boes, Xingyuan Xu, Mengxi Tan, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, David J. Moss, and Bill Corcoran, "Frequency comb distillation for optical superchannel transmission", Journal of Lightwave Technology vol. 39 (23) 7383-7392 (2021). DOI: 10.1109/JLT.2021.3116614.

165. Mengxi Tan, Xingyuan Xu, Jiayang Wu, Bill Corcoran, Andreas Boes, Thach G. Nguyen, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, and David J. Moss, "Integral order photonic RF signal processors based on a soliton crystal micro-comb source", IOP Journal of Optics vol. 23 (11) 125701 (2021). https://doi.org/10.1088/2040-8986/ac2eab

166. Yang Sun, Jiayang Wu, Yang Li, Xingyuan Xu, Guanghui Ren, Mengxi Tan, Sai Tak Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, and David J. Moss, "Optimizing the performance of microcomb based microwave photonic transversal signal processors", Journal of Lightwave Technology vol. 41 (23) pp 7223-7237 (2023). DOI: 10.1109/JLT.2023.3314526.

167. Mengxi Tan, Xingyuan Xu, Andreas Boes, Bill Corcoran, Thach G. Nguyen, Sai T. Chu, Brent E. Little, Roberto Morandotti, Jiayang Wu, Arnan Mitchell, and David J. Moss, "Photonic signal processor for real-time video image processing based on a Kerr microcomb", Communications Engineering vol. 2 94 (2023). DOI:10.1038/s44172-023-00135-7

168. Mengxi Tan, Xingyuan Xu, Jiayang Wu, Roberto Morandotti, Arnan Mitchell, and David J. Moss, "Photonic RF and microwave filters based on 49GHz and 200GHz Kerr microcombs", Optics
Communications, vol. 465, Article: 125563 (2020). doi:10.1016/j.optcom.2020.125563.
doi.org/10.1063/1.5136270.

169. Yang Sun, Jiayang Wu, Yang Li, Mengxi Tan, Xingyuan Xu, Sai Chu, Brent Little, Roberto Morandotti, Arnan Mitchell, and David J. Moss, "Quantifying the Accuracy of Microcomb-based Photonic RF Transversal Signal Processors", IEEE Journal of Selected Topics in Quantum Electronics vol. 29 no. 6, pp. 1-17, Art no. 7500317 (2023). 10.1109/JSTQE.2023.3266276.

170. Yang Li, Yang Sun, Jiayang Wu, Guanghui Ren, Bill Corcoran, Xingyuan Xu, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, and David J. Moss, "Processing accuracy of microcomb-based microwave photonic signal processors for different input signal waveforms", MDPI Photonics 10, 10111283 (2023). DOI:10.3390/photonics10111283

171. Caitlin E. Murray, Mengxi Tan, Chawaphon Prayoonyong, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, David J. Moss and Bill Corcoran, "Investigating the thermal robustness of soliton crystal microcombs", Optics Express 31(23), 37749-37762 (2023).

172. Yang Sun, Jiayang Wu, Yang Li, and David J. Moss, "Comparison of microcomb-based RF photonic transversal signal processors implemented with discrete components versus integrated chips", MDPI Micromachines 14, 1794 (2023). https://doi.org/10.3390/mi14091794

173. Kues, M. et al. "Quantum optical microcombs", Nature Photonics vol. 13, (3) 170-179 (2019).
doi:10.1038/s41566-019-0363-0

174. C. Reimer, L. Caspani, M. Clerici, et al., "Integrated frequency comb source of heralded single photons," Optics Express, vol. 22, no. 6, pp. 6535-6546, 2014.

175. C. Reimer, et al., "Cross-polarized photon-pair generation and bi-chromatically pumped optical parametric oscillation on a chip", Nature Communications, vol. 6, Article 8236, 2015. DOI: 10.1038/ncomms9236.

176. L. Caspani, C. Reimer, M. Kues, et al., "Multifrequency sources of quantum correlated photon pairs on-chip: a path toward integrated Quantum Frequency Combs," Nanophotonics, vol. 5, no. 2, pp. 351-362, 2016.

177. C. Reimer et al., "Generation of multiphoton entangled quantum states by means of integrated frequency combs," Science, vol. 351, no. 6278, pp. 1176-1180, 2016.

178. M. Kues, et al., "On-chip generation of high-dimensional entangled quantum states and their coherent control", Nature, vol. 546, no. 7660, pp. 622-626, 2017.

179. P. Roztocki et al., "Practical system for the generation of pulsed quantum frequency combs," Optics Express, vol. 25, no. 16, pp. 18940-18949, 2017.

180. Y. Zhang, et al., "Induced photon correlations through superposition of two four-wave mixing processes in integrated cavities", Laser and Photonics Reviews, vol. 14, no. 7, pp. 2000128, 2020. DOI: 10.1002/lpor.202000128

181. C. Reimer, et al., "High-dimensional one-way quantum processing implemented on d-level cluster states", Nature Physics, vol. 15, no.2, pp. 148-153, 2019.

182. P. Roztocki et al., "Complex quantum state generation and coherent control based on integrated frequency combs", Journal of Lightwave Technology vol. 37 (2) 338-347 (2019).

183. S. Sciara et al., "Generation and Processing of Complex Photon States with Quantum Frequency Combs", IEEE Photonics Technology Letters vol. 31 (23) 1862-1865 (2019). DOI: 10.1109/LPT.2019.2944564.
Communications, vol. 465, Article: 125563 (2020). doi:10.1016/j.optcom.2020.125563.
doi.org/10.1063/1.5136270.

169. Yang Sun, Jiayang Wu, Yang Li, Mengxi Tan, Xingyuan Xu, Sai Chu, Brent Little, Roberto Morandotti, Arnan Mitchell, and David J. Moss, "Quantifying the Accuracy of Microcomb-based Photonic RF Transversal Signal Processors", IEEE Journal of Selected Topics in Quantum Electronics vol. 29 no. 6, pp. 1-17, Art no. 7500317 (2023). 10.1109/JSTQE.2023.3266276.

170. Yang Li, Yang Sun, Jiayang Wu, Guanghui Ren, Bill Corcoran, Xingyuan Xu, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, and David J. Moss, "Processing accuracy of microcomb-based microwave photonic signal processors for different input signal waveforms", MDPI Photonics 10, 10111283 (2023). DOI:10.3390/photonics10111283

171. Caitlin E. Murray, Mengxi Tan, Chawaphon Prayoonyong, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, David J. Moss and Bill Corcoran, "Investigating the thermal robustness of soliton crystal microcombs", Optics Express 31(23), 37749-37762 (2023).

172. Yang Sun, Jiayang Wu, Yang Li, and David J. Moss, "Comparison of microcomb-based RF photonic transversal signal processors implemented with discrete components versus integrated chips", MDPI Micromachines 14, 1794 (2023). https://doi.org/10.3390/mi14091794

173. Kues, M. et al. "Quantum optical microcombs", Nature Photonics vol. 13, (3) 170-179 (2019).
doi:10.1038/s41566-019-0363-0

174. C. Reimer, L. Caspani, M. Clerici, et al., "Integrated frequency comb source of heralded single photons," Optics Express, vol. 22, no. 6, pp. 6535-6546, 2014.

175. C. Reimer, et al., "Cross-polarized photon-pair generation and bi-chromatically pumped optical parametric oscillation on a chip", Nature Communications, vol. 6, Article 8236, 2015. DOI: 10.1038/ncomms9236.

176. L. Caspani, C. Reimer, M. Kues, et al., "Multifrequency sources of quantum correlated photon pairs on-chip: a path toward integrated Quantum Frequency Combs," Nanophotonics, vol. 5, no. 2, pp. 351-362, 2016.

177. C. Reimer et al., "Generation of multiphoton entangled quantum states by means of integrated frequency combs," Science, vol. 351, no. 6278, pp. 1176-1180, 2016.

178. M. Kues, et al., "On-chip generation of high-dimensional entangled quantum states and their coherent control", Nature, vol. 546, no. 7660, pp. 622-626, 2017.

179. P. Roztocki et al., "Practical system for the generation of pulsed quantum frequency combs," Optics Express, vol. 25, no. 16, pp. 18940-18949, 2017.

180. Y. Zhang, et al., "Induced photon correlations through superposition of two four-wave mixing processes in integrated cavities", Laser and Photonics Reviews, vol. 14, no. 7, pp. 2000128, 2020. DOI: 10.1002/lpor.202000128

181. C. Reimer, et al., "High-dimensional one-way quantum processing implemented on d-level cluster states", Nature Physics, vol. 15, no.2, pp. 148-153, 2019.

182. P. Roztocki et al., "Complex quantum state generation and coherent control based on integrated frequency combs", Journal of Lightwave Technology vol. 37 (2) 338-347 (2019).

183. S. Sciara et al., "Generation and Processing of Complex Photon States with Quantum Frequency Combs", IEEE Photonics Technology Letters vol. 31 (23) 1862-1865 (2019). DOI: 10.1109/LPT.2019.2944564.
184. Stefania Sciara, Piotr Roztocki, Bennet Fisher, Christian Reimer, Luis Romero Cortez, William J. Munro, David J. Moss, Alfonso C. Cino, Lucia Caspani, Michael Kues, J. Azana, and Roberto Morandotti, "Scalable and effective multilevel entangled photon states: A promising tool to boost quantum technologies", Nanophotonics vol. 10 (18), 4447-4465 (2021). DOI:10.1515/nanoph-2021-0510.

185. L. Caspani, C. Reimer, M. Kues, et al., "Multifrequency sources of quantum correlated photon pairs on-chip: a path toward integrated Quantum Frequency Combs," Nanophotonics, vol. 5, no. 2, pp. 351-362, 2016.

186. L Carletti, P Ma, Y Yu, B Luther-Davies, D Hudson, C Monat, ..., et al., "Nonlinear optical response of low loss silicon germanium waveguides in the mid-infrared", Optics Express vol. 23 (7), 8261-8271 (2015).

187. C. Mazoukh, L. Di Lauro, I. Alamgir, B. Fischer, A. Aadhi, A. Eshaghi, B. E. Little, S. T. Chu, D. J. Moss, and R. Morandotti, "Genetic algorithm-enhanced microcomb state generation", Nature Communications Physics Vol. 7, Article: 81 (2024). DOI: 10.1038/s42005-024-01558-0.

188. Junkai Hu, Jiayang Wu, Di Jin, Sai Tak Chu, Brent E. Little, Duan Huang, Roberto Morandotti, and David J. Moss, "Thermo-optic response and optical bistability of integrated high index doped silica ring resonators", MDPI Sensors 23 9767 (2023). https://doi.org/10.3390/s23249767.

189. M. Zerbib, V.T. Hoang, J. C. Beugnot, K. P. Huy, B. Little, S. T. Chu, D. J. Moss, R. Morandotti, B. Wetzel, and T. Sylvestre, "Observation of Brillouin scattering in a high-index doped silica chip waveguide", Results in Physics 52 106830 (2023). https://doi.org/10.1016/j.rinp.2023.106830.

190. Stefania Sciara, Hao Yu, Farzam Nosrati, Piotr Roztocki, Bennet Fischer, Mario Chemnitz, Christian Reimer, Luis Romero Cortés, William J. Munro, David J. Moss, Rosario Lo Franco, Alfonso C. Cino, Lucia Caspani, Michael Kues, Zhiming Wang, José Azaña, and Roberto Morandotti, "Generation of integrated quantum frequency combs on microring resonators for the realization of complex entangled two-photon states", Early Access IEEE Journal of Selected Topics in Quantum Electronics 28 (2022).

191. Linnan Jia, Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Baohua Jia, and David J. Moss, "Third-order optical nonlinearities of 2D materials at telecommunications wavelengths", Micromachines, 14 307 (2023). https://doi.org/10.3390/mi14020307.
184. Stefania Sciara, Piotr Roztocki, Bennet Fisher, Christian Reimer, Luis Romero Cortez, William J. Munro, David J. Moss, Alfonso C. Cino, Lucia Caspani, Michael Kues, J. Azana, and Roberto Morandotti, "Scalable and effective multilevel entangled photon states: A promising tool to boost quantum technologies", Nanophotonics vol. 10 (18), 4447-4465 (2021). DOI:10.1515/nanoph-2021-0510.

185. L. Caspani, C. Reimer, M. Kues, et al., "Multifrequency sources of quantum correlated photon pairs on-chip: a path toward integrated Quantum Frequency Combs," Nanophotonics, vol. 5, no. 2, pp. 351-362, 2016.

186. L Carletti, P Ma, Y Yu, B Luther-Davies, D Hudson, C Monat, ..., et al., "Nonlinear optical response of low loss silicon germanium waveguides in the mid-infrared", Optics Express vol. 23 (7), 8261-8271 (2015).

187. C. Mazoukh, L. Di Lauro, I. Alamgir1 B. Fischer, A. Aadhi, A. Eshaghi, B. E. Little, S. T. Chu, D. J. Moss, and R. Morandotti, "Genetic algorithm-enhanced microcomb state generation", Nature Communications Physics Vol. 7, Article: 81 (2024). DOI: 10.1038/s42005-024-01558-0.

188. Junkai Hu, Jiayang Wu, Di Jin, Sai Tak Chu, Brent E. Little, Duan Huang, Roberto Morandotti, and David J. Moss, "Thermo-optic response and optical bistability of integrated high index doped silica ring resonators", MDPI Sensors 23 9767 (2023). https://doi.org/10.3390/s23249767.

189. M. Zerbib, V.T. Hoang, J. C. Beugnot, K. P. Huy, B. Little, S. T. Chu, D. J. Moss, R. Morandotti, B. Wetzel, and T. Sylvestre, "Observation of Brillouin scattering in a high-index doped silica chip waveguide", Results in Physics 52 106830 (2023). https://doi.org/10.1016/j.rinp.2023.106830.

190. Stefania Sciara, Hao Yu, Farzam Nosrati, Piotr Roztocki, Bennet Fischer, Mario Chemnitz, Christian Reimer, Luis Romero Cortés, William J. Munro, David J. Moss, Rosario Lo Franco, Alfonso C. Cino, Lucia Caspani, Michael Kues, Zhiming Wang, José Azaña, and Roberto Morandotti, "Generation of integrated quantum frequency combs on microring resonators for the realization of complex entangled two-photon states", Early Access IEEE Journal of Selected Topics in Quantum Electronics 28 (2022).

191. Linnan Jia, Yang Qu, Jiayang Wu, Yuning Zhang, Yunyi Yang, Baohua Jia, and David J. Moss, "Third-order optical nonlinearities of 2D materials at telecommunications wavelengths", Micromachines, 14 307 (2023). https://doi.org/10.3390/mi14020307.