bluuebunny/crossref_metadata_2025 huggingface dataset:
A Micro-LED Driver with Bandwidth Expansion for Visible Light Communications
Authors: Sun Liusheng , Hussain Babar , Li Xianbo , Zhu Guang , Yue C. Patrick
Published: February 2023

Visible light communication (VLC) using LEDs has generated strong research interest recently [1, 2]. Many existing LEDs in display applications can be employed as transmitters for the further deployment of VLC. The first active matrix LED (AMLED) micro-display with an embedded VLC transmitter was reported in [2], with a 5-Mb/s modulation bit rate. This paper presents an AMLED system, consisting of a proposed CMOS pixel driver and a flip-chip bonded blue gallium nitride (GaN) micro-LED (μLED) array with 36×64 pixels of 40×40 μm2, for simultaneous display and VLC applications. Measurement results show that the proposed pixel driver can achieve a 20-Mb/s bit rate at 10 cm, which is four times as large as the 5-Mb/s modulation bit rate in [2].
Exciton Hall effect and transport of valley exciton in monolayer MoS2
Authors: Onga Masaru , Zhang Yijin , Ideue Toshiya , Iwasa Yoshihiro
Published: February 2023

Transition metal dichalcogenides (TMDs) have attracted vast interest as layered semiconductors with high electrical and optical properties. Among them, monolayer MoS2 is a direct gap semiconductor with its gap energy in the visible range (Fig. 1(a)). Interestingly, excitonic states in monolayer MoS2 are stabilized owing to the intrinsic two-dimensional nature, and the binding energy reaches several hundred meV.
Identification of PL emissions from Interlayer Excitons in 2D van der Waals Heterostructures
Authors: Okada Mitsuhiro , Kureishi Yusuke , Kutana Alex , Watanabe Kenji , Taniguchi Takashi , Shinohara Hisanori , Kitaura Ryo
Published: February 2023

Two-dimensional (2D) semiconductors, including MoS2, WS2, MoSe2, etc., have provided a fascinating opportunity to explore optical properties in 2 dimensions. In particular, van der Waals (vdW) heterostructures composed of these 2D semiconductors, such as WS2/MoS2, offer a novel platform for optical physics arising from interlayer excitons. It is, however, not straightforward to understand optical response from interlayer excitons because contributions from interlayer excitons with different transition energies overlap to a show broad peak in optical spectra. In this work, we have focused on the assignment of PL emission from interlayer excitons by using hBN-sandwiched high-quality samples.
Electrochemical modulation of single-layer MoS2 photoluminescence under aqueous electrolyte solution for potential biological sensing
Authors: Seki Takakazu , Yatsu Kazuki , Hayamizu Yuhei
Published: February 2023

Functionalization of the surface of biosensors with biomaterials such as proteins and DNA has been widely employed to establish a specific selectivity and high sensitivity to target molecules. As for sensing materials, a group of transition metal dichalcogenides (TMDC), e.g., MoS2 and WS2, has attracted much attention due to their superior optoelectronic properties as well as its atomically flat surface. Single-layer MoS2 has shown strong photoluminescence (PL) under photoexcitation, and the PL is largely affected by surrounding environments, such as molecular adsorption and solvent [1,2]. Thus, MoS2 can be a good candidate for an optical biosensor under physiological condition due to its high sensitivity to the environments. To this end, it is necessary to investigate the optical response of MoS2 to various aqueous conditions of pH and ions. However, despite of intensive studies, the MoS2 PL under aqueous solution is poorly investigated.
GeSe/MoS2 heterojunction diode for optoelectronic applications
Authors: Tan Dezhi , Miyauchi Yuhei , Matsuda Kazunari
Published: February 2023

Heterostructure engineering of two-dimensional (2D) layered materials offers an exciting opportunity to take advantage of each building block for fabricating new electronic and optical devices. The p-n junction diode constructed by heterostructures of 2D layered materials (e.g., MoS2/WSe2, MoS2/black phosphorus,) have been demonstrated to be excellent candidates for high-sensitive photodetectors with broad spectral response [1,2]. Recently, IV family monochalcogenides (e.g., GeS and GeSe) have been introduced as a new member of 2D material family and attracted much attention for the highly sensitive photodetector applications. The p-type semiconductor 2D GeSe has an orthorhombic structure with the band gap at around 1.1 eV. Accompanied by its strong light absorption property, the GeSe shows high-potential working as a photodetector with a broadband response from ultra-violate to near-infrared spectral regions [3]. By stacking n-type MoS2 and p-type GeSe, the formation of heterojunction diode is highly promising with unique optoelectronic properties.
Terahertz plasmonic slab waveguide based on a metal rod array
Authors: Liu Dejun , Takaki Ryohei , You Borwen , Lu Ja-Yu , Hattori Toshiaki
Published: February 2023

Terahertz (THz) plasmonic devices typically consist of metallic structures with micrometer- or subwavelength-scaled units, and lead to excellent optical properties, such as the field confinement and enhancement [1]. Such unique performances are attractive and considered as the features of novel photonic devices in THz frequency region. However, the confined waveguide field normally results in the strong waveguide attenuation and dispersion [2], consequently hindering the possible applications of THz plasmonic devices. Therefore, engineering the periodic metal structure of a THz plasmonic device to transport THz waves with high field confinement and low loss is urgently requested currently. In this presentation, one THz plasmonic slab waveguide based on a free-standing metal rod array (MRA) is demonstrated, and the waveguide modal field tailored via the MRA parameters is successfully achieved [3].
Waveguide design for GaN/AlGaN terahertz quantum cascade lasers
Authors: Wang° Ke , Lin Tsung-Tse , Terashima Wataru , Hirayama Hideki
Published: February 2023

III-nitrides which have much larger phonon energies (91meV in GaN) can in principle allow for terahertz quantum cascade lasers (THz QCLs) to operate at higher temperatures than GaAs based THz QCLs[1-2], in which the thermally activated phonon scattering depopulation and backfilling are limiting THz lasing at <200 K. GaN THz-QCLs would be key coherent sources in the unexplored terahertz frequency range of 5-12 THz, at which GaAs THz-QCLs are not able to work due to the Reststrahlen band.
LT-GaAs carrier lifetime evaluation using THz and optical probe techniques at different carrier injection levels
Authors: Afalla Jessica Pauline , Mag-usara Valynn Katrine , Moriyasu Takeshi , Kitahara Hideaki , Tani Masahiko
Published: February 2023

A typical photoconductive antenna (PCA)-based terahertz time-domain spectroscopy (THz-TDS) system has a mode-locked Ti: sapphire laser with a 100-MHz repetition rate as the pulsed excitation source. When an average probe beam power of 10 mW is focused to a 10-μm diameter on a semiconductor substrate, it yields an estimated fluence of around 130 μJ/cm2 impinging on the spot. The temporal resolution of the system highly depends on the speed of the PCA material. In this study, we evaluate the response of a low temperature-grown gallium arsenide, “LT-GaAs”, (grown at 210°C) layer at different carrier injection levels. LT-GaAs has been highly favored as a photoconductive material for THz applications due to its high carrier mobility, high dark resistivity and short carrier lifetimes [1].
Carbon nanotube films for perovskite solar cells
Authors: Maruyama Shigeo
Published: February 2023

A film of single-walled carbon nanotubes (SWNTs) can be flexible and stretchable transparent-conductive layer. At the same time, this film can be carrier-selective layers, i.e., electron-blocking-layers or hole-blocking-layers, by using adequate doping. We have demonstrated efficient SWNT/Si solar cells [1,2] and organic solar cells [3,4] using dry-deposited high-quality SWNTs and honeycomb-structured SWNTs. For organic solar cells, the SWNT doped by MoOx and PEDOT:PSS demonstrated a dual function, which can replace both ITO and electron-blocking-layer [3]. Using this advantage of the SWNT film, flexible organic solar cells were fabricated with ease [3]. Also, it was possible to replace electron-blocking-layer and metal electrode for inverted-type organic solar cells [4]. The removal of metal electrode enabled flexible, the semi-transparent window-like solar cells, which was inexpensive in their production process [4]. Here we have extended the application of CNT films for organic-inorganic Perovskite solar cells.
Spectral tuning of optical coupling between air-mode nanobeam cavities and individual carbon nanotubes
Authors: Machiva H. , Uda T. , Ishii A. , Kato Y. K.
Published: February 2023

Air-mode nanobeam cavities allow for high efficiency coupling to air-suspended carbon nanotubes due to their unique mode profile that has large electric fields in air [1]. We have fabricated air-mode nanobeam cavities from silicon-on-insulator wafers and grown carbon nanotubes on top of the cavities (Fig. 1). Here we utilize heating-induced energy shift of carbon nanotube emission [2] to investigate the cavity quantum electrodynamics effects. In particular, we use laser-induced heating which causes a large blue-shift of the nanotube photoluminescence as the excitation power is increased. Combined with a slight red-shift of the cavity mode at high powers, the spectral overlap between the nanotube emission and the cavity can be controlled. We estimate the spontaneous emission enhancement at different spectral overlaps and find linear increase of the enhancement factor as the spectral overlap improves, which is consistent with Purcell enhancement of nanotube emission.
Single-carbon-nanotube photonics and optoelectronics
Authors: Kato Yuichiro K.
Published: February 2023

Single-walled carbon nanotubes have unique optical properties as a result of their one-dimensional structure. Reduced screening leads to large exciton binding energies which allow for room-temperature excitonic luminescence, while enhanced interactions give rise to a variety of exciton processes that may be utilized for modulating the emission properties. Furthermore, their luminescence is in the telecom-wavelengths and they can be directly synthesized on silicon substrates, providing new opportunities for nanoscale quantum photonics and optoelectronics.
Shape Effects of CNT Forest Metamaterials on IR and THz Properties
Authors: Furuta Hiroshi , Pander Adam , Takano Keisuke , Miyaji Hiroki , Hatta Akimitsu , Nakajima Makoto
Published: February 2023

Anisotropic black body absorption has been reported in high-density and vertically-oriented carbon nanotube (CNT) forests[1]. Recently, THz wave generation was reported from perpendicularly aligned CNT films placed on substrates[2]. Unique optical properties of CNT forests opened the next door of opt-electronics applications. Size and shape controlled CNTs is a candidate of metamaterial nano-rod antenna in THz to the visible range. In this paper, we report anisotropic optical properties of vertically aligned CNT forests with/without SRR (Split ring resonator) patterning in IR and THz regions.
Doping effects on minority-carrier lifetimes in ultrananocrystalline diamond/hydrogenated amorphous carbon composite films
Authors: Nishikawa Naofumi , Takeichi Satoshi , Tategami Shuya , Takauchi Kenjiro , Matsuda Naoki , Katamune Yuki , Fukuyama Atsuhiko , Yoshitake Tsuyoshi
Published: February 2023

Ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) composite (UNCD/a-C:H) films possess specific characteristics as follows: (a) the appearance of additional energy levels in diamond bandgap [1]; and (b) large absorption coefficients ranging from visible to ultraviolet [2], both of which might be due to large number of grain boundaries between UNCD grains and those between UNCD grains and a-C:H [1,3]. Owing to the above-mentioned specifics, UNCD/a-C:H films are expected to be applied to photovoltaics such as UV sensors. Actually, we have fabricated pn heterojunction diodes comprising UNCD/a- C:H films and Si substrates, and confirmed their photocurrents [4,5]. Although the minority-carrier lifetime is an important factor for photovoltaics, it has never been studied for UNCD/a-C:H. In this work, we experimentally measured the minority carrier lifetimes for typical samples.
Near-field Measurements of Terahertz Meta-atoms with Localized Terahertz Sources
Authors: Serita Kazunori , Darmo Juraj , Kawayama Iwao , Murakami Hironaru , Tonouchi Masayoshi
Published: February 2023

Terahertz (THz) metamaterials is very attractive due to their fascinating electromagnetic properties and potentials for building unique optical components and devices[1]. The meta-atom, an elementary unit of the metamaterial, is an electromagnetic resonator with non-zero magnetic and electric dipoles. Coupling between the meta-atoms and THz waves has great attention to investigate the dynamics of the metamaterials. However, the majority of THz metamaterial studies so far has focused on investigating the response of the meta-atom when a few hundred or thousands of its neighbor meta-atoms are excited with far-field THz waves. Then one or several of the meta-atoms are measured with far-field THz-wave and near-field probe. Therefore, those studies using the near-field probe are overlooking the details of the interaction between local THz electromagnetic field and a meta-atom. On the other hand, we have developed a scanning laser THz near-field imaging system[2]. In the system, a nonlinear optical crystal was employed as a THz emitter and THz waves were locally generated in the process of optical rectification at the irradiation spots of femtosecond laser beams. By setting samples in the vicinity of the THz source, THz-TDS and THz imaging of samples of sub-THz wavelength scale have been achieved. Since the size of the generated THz radiation source is smaller than that of meta-atom, the technique allows us to investigate the near-field coupling effects between a single excited meta-atom and its neighboring non-excited meta-atoms[3]. Therefore, in this study, we present direct measurements of the interaction of THz radiation with the meta-atoms of a THz metamaterial by using this system.
Enhanced sensitivity of MEMS bolometers by introducing two-dimensional phononic crystal structures
Authors: Zhang Y. , Qiu B. , Nagai N. , Nomura M. , Hirakawa K.
Published: February 2023

Microelectromechanical system (MEMS)-based resonators are very attractive for sensing applications owing to their high sensitivities. Recently, we proposed an uncooled, all electrical driving and detecting, sensitive bolometer by using a doubly clamped MEMS beam resonator, which is very promising for realizing high sensitivity and fast terahertz (THz) detection at room temperature1. The sensitivity of the MEMS bolometer is inversely proportional to the thermal conductivity of the beam and it has been considered that its value is specific to the material and cannot be changed.
Tunable reflective liquid crystal terahertz waveplates
Authors: Wang Lei , Lu Yanqing , Nakajima Makoto
Published: February 2023

Tunable liquid crystal devices that can change terahertz (THz) wave polarization continuously have many potential applications in THz optical systems [1]. We present a reflective liquid crystal THz waveplate with sub-wavelength metal grating and metal ground plane electrodes [2]. The thickness of the liquid crystal layer can be reduced to ~10% of that needed for the same phase shift at a given frequency in a transmissive waveplate. We experimentally demonstrate the same tunability as in the transmissive type just using half the thickness [3]. We discuss the dependence on the angle of incidence for phase shift tunability, which can achieve beam steering and polarization conversion at the same time.
Multiparameter estimation with single photons—Linearly-optically generated quantum entanglement beats the shotnoise limit
Authors: You Chenglong , Adhikari Sushovit , Chi Yuxi , LaBorde Margarite L. , Matyas Corey T. , Zhang Chenyu , Su Zuen , Byrnes Tim , Lu Chaoyang , Dowling Jonathan P. , Olson Jonathan P.
Published: February 2023

It was previously shown that optical networks using only single photon Fock states, passive linear optics, and single photon detection could achieve post-classical sensitivity for singleparameter estimation when the mode number is small. [1] Furthermore, it was shown that multiparameter estimation could achieve similar results with number-resolving detection. [2] Here, we consider an analogous architecture to the Quantum Fourier Transform Interferometer(QuFTI) proposed in [1] for the estimation of multiple phases simultaneously. Thus, we will see that this yields post-classical sensitivity for multiparameter estimation even for an asymptotically large number of modes. This system is also considered for nondeterministic photon sources and a variety of measurement schemes.
Observation of self-organized coherence in dissipative spinor Bose-Einstein condensates
Authors: Eto Yujiro , Shibayama Hitoshi , Torii Aki , Saito Hiroki , Hirano Takuya
Published: February 2023

Dissipation is a ubiquitous phenomenon, and it is important to understand its role in non-equilibrium dynamics. In the quantum systems, dissipation often reduce the coherence of the quantum states. But sometimes, it induces completely different effects than the decoherence. For example, strong dissipation can be used to suppress the loss [1] and control the quantum state [2] and quantum phase transition [3].
Phase separation of Rabi-coupled spin states in an 87Rb F = 1 BEC
Authors: Shibata Kosuke , Shibayama Hitoshi , Torii Aki , Suzuki Ryota , Toda Hiroyuki , Eto Yujiro , Takahashi Masahiro , Saito Hiroki , Hirano Takuya
Published: February 2023

A Bose-Einstein condensate (BEC) in cold atoms allows us to explore the nature of quantum phenomena in a controlled way. One of the most common tools for the control of a BEC system is an electromagnetic field. Particularly, the Rabi oscillations induced by light or RF pulses are often used for manipulation of the magnetic sublevels in atoms. The electromagnetic field can also change the interatomic interaction via the state mixing.
Measuring elasticity of HeLa cells by laser trapping
Authors: Statsenko Anna , Inami Wataru , Kawata Yoshimasa , Poperenko Leonid
Published: February 2023

The objective of our research is to develop the non-invasive method for measuring the elasticity of the biological cells. We developed the experimental setup shown at Fig.1. It consists of optical microscope and laser trapping system. In order to avoid cell damage the NIR laser was used as trapping and detection laser. Figure 1 Experimental setup for laser trapping.
Optical Metasurface for the Creation and Applications of Surface Plasmon Vortices
Authors: Huang Chen-Bin (Robin)
Published: February 2023

Optical vortices are waves carrying orbital angular momentum and exhibit helical phase fronts. Helical phase front leads to discontinuous azimuthal phase jumps and the number of phase discontinuities (abrupt phase jumps from −π to π) within a 2π range is referred to as the topological charge of an optical vortex. Optical vortices have been applied in trapping and spinning of microparticles, and recently in free-space data transmission. Generation of optical beams carrying orbital angular momentum has received increasing attentions recently, both in the far-field and in the near-field. Near-field vortices are typically generated through the excitation of surface plasmons (SP). However, the intensity patterns of the SP vortices generated thus far, just like the free-space vortex beams, are all azimuthally symmetrical (annular) since mathematically they conform to the Bessel function.
Label-free imaging to single nanoparticle by using TIR-based Interface Scattering
Authors: Jiang Liwen , Sun Xuqing , Liu Hongyao , Xiong Wei , Chen Yaqin , Lu Xinchao
Published: February 2023

Total Internal Reflection (TIR) microscopy combining fluorescent probe has been widely used in the bio-imaging. As the bleaching and quenching introduced by the fluorescent probe, people kept on looking for the label-free microscopic method. Studies on label-free imaging has been implemented by collecting the space scattering of evanescent wave excited by total internal reflection, and imaging to ~40 nm single gold nanoparticle and ~ 100 nm single virus has been achieved [1-2]. Here, we introduced a novel label-free TIR-based Interface Scattering approach, which images the single nanoparticle by using the interface scattering of evanescent wave. The evanescent wave excited by TIR-based illumination, then the nanoparticle polarizes and emits the scattering which includes both space and interface scattering (shown in Figure 1). The interface scattering interferes with the incident evanescent wave is collected for imaging. We presented the imaging of single 200nm and 100nm polystyrene nanoparticle (shown in Figure 2). This approach is potential for application in fast, in-situ, label-free nanoscale imaging.
Synthesis and evaluation of fluorescent palladium nanoclusters
Authors: Baba Tsutomu , Ishitobi Hidekazu , Masui Kyoko , Inouye Yasushi
Published: February 2023

Metal nanoclusters consisting of a few to several tens of atoms have discrete energy states due to quantum size effects, which allows them to emit fluorescent. The fluorescent wavelength is dependent on the size of metal nanoclusters [1]. Much of studies on fluorescent metal nanoclusters have been focused on gold and silver. Recently we have succeeded in synthesizing platinum (Pt) nanoclusters which emit blue to yellow fluorescence [2-5]. Here we report on synthesis of fluorescent nanoclusters consisting of palladium (Pd) atoms.
Metamaterial absorbers and their applications
Authors: Tanaka Takuo
Published: February 2023

Recent advances in metamaterials enable us to create unprecedented optical materials, and as a example of such materials, perfect absorptive material surfaces within a certain frequency range were demonstrated. Since the metamaterial absorber offers a unique surface condition with tailored absorption properties, a wide variety of potential applications have been proposed.
A Challenge to Tunable Metamaterial Optical Retarder: Au Nanograting and its Integration with Microelectromechanical Actuators
Authors: Iwami° Kentaro
Published: February 2023

Optical metasurface attracts interest as novel micro-optical elements including flat lenses, polarization converters, retarders, waveplates and so on. Metasurfaces are able to have tailored in-plane distribution of optical characteristics. Especially, metasurface optical retarders have opened up advanced optical elements applications such as Laguerre-Gaussian beam converters, optical vortex converters, and computer-generated holography. However, plasmonic metasurfaces have a tradeoff problem between transmittance and retardation because of the lossy nature of metal.
Residual Interpolation for Micropolarizer Array Patterns of Polarization Image Sensors
Authors: Ahmed Ashfaq , Zhao Xiaojin , Gruev Viktor , Bermak Amine
Published: February 2023

In this paper, we have applied residual interpolation to low-resolution polarized images of different micropolarizer patterns for division of focal plane (DoFP) polarization image sensors. We observed the polarization accuracy recovery through visual evaluation of intensity, degree of linear polarization (DoLP) and angle of linear polarization (AoP) images and found that residual interpolation works well on a 4-micropolarizer pattern of a rooster image.
Optimization of modulation efficiency of InGaAsP/Si hybrid MOS optical modulator
Authors: Li Qiang , Takagi Shinichi , Takenaka Mitsuru
Published: February 2023

Si optical modulators suffer from low modulation efficiency and high absorption loss. To improve the modulation efficiency, we have proposed to use an InGaAsP/Si hybrid metal-oxide-semiconductor (MOS) structure for a phase shifter by using direct wafer bonding [1]. Owing to the large electron-induced refractive index change in InGaAsP, we have successfully demonstrated extremely high modulation efficiency of approximately 0.05 Vcm [2]. In this study, we conducted the optimization of the device structure to further improve the modulation efficiency through increasing the overlap between the optical mode and accumulated electrons at the InGaAsP MOS interface.
Polarization Imaging with a waveplate array of femtosecond laser written nanogratings inside silica glass
Authors: Sakakura Masaaki , Ohfuchi Takafumi , Yamada Yuya , Fukuda Naoaki , Takiya Toshio , Shimotsuma Yasuhiko , Miura Kiyotaka
Published: February 2023

Nanograting formation inside silica glass by femtosecond (fs) laser writing has attracted much attention [1], because micro birefringent optics can be fabricated by local generation of nanogratings [2,3]. One application of the micro birefringent optics is a waveplate array for polarization imaging [3]. In a polarization imaging camera, the incident light is detected by an imaging sensor after passing through a waveplate array and polarizer (Fig. 1 (a)). Because four intensities through waveplates of different slow axis are detected by four adjacent detectors in the imaging sensor (Fig. 1 (b)), polarization state can be analyzed only by a single acquisition of the light intensity distribution.
Spatial control of crystal growth of L-phenylalanine by laser ablation
Authors: Wu Chi-Shiun , Sugiyama Teruki , Nakabayashi Seiichiro , Yoshikawa Hiroshi
Published: February 2023

Control of crystal growth is important in various scientific or industrial processes such as purification, crystalline devises, X-ray crystallography, and so on. Most of studies have focused so far to the control of crystal growth by adjusting environmental parameters such as additive, solvent, and temperature. On the other hand, we have recently reported an innovative approach for promoting protein crystal growth by the direct modification of the local crystal structure utilizing femtosecond laser ablation [1]. The protein crystal with surfaces etched locally by femtosecond laser ablation showed the enhancement of the growth rate. We explained the mechanism based on the laser-induced spiral growth mode, which is energetically advantageous compared to the spontaneous two-dimensional nucleation growth mode. In this study, we apply the laser method to growth control of L-phenylalanine (L-Phe) crystal, which shows several crystal polymorph with different morphology (e.g., plates, needles, etc) depending on solution conditions.
Space-Selective Modification of Glass by Using Femtosecond Laser
Authors: Zhou Shifeng , Yu Yongze , Qiu Jianrong
Published: February 2023

Laser induced modification and damage in transparent materials (e.g., glass) has attracted considerable interest and been studied since the advent of high power pulsed lasers. Especially while using a femtosecond laser as the irradiation source, the tight focusing and nonlinear nature of the absorption make it possible to confine the absorption to the focal volume inside the bulk of the material, allowing for micromaching in extremely small region. In this talk, we introduce the progress in space-selective modification of glass by using femtosecond laser. We show that some fundamental processes, including valence state change of dopant, decomposition of cluster, element redistribution, phase transition and nanocrystallization, can occur in the femtosecond laser irradiation region inside glass. As a result, the optical response of the modified glass can be controlled. For examples, the luminescence properties of main group ions doped glass can be tuned and tunable luminescence can be achieved. The microstructures with multicolor luminescence can be induced. The results suggest that space-selective modification of glass by using femtosecond laser can be applied to fabricate various types of 3D active microstructures.
Strategies for in-situ thin film filter monitoring with a broadband spectrometer
Authors: Zideluns Janis , Lemarchand Fabien , Arhilger Detlef , Hagedorn Harro , Lumeau Julien
Published: February 2023

Optical monitoring of thin film interference filters is of primary importance for two main reasons: possible error compensation and greater thickness accuracy of the deposited layers compared to non-optical methods. For many designs, the latter reason is the most crucial, because for complex designs with a large number of layers, several witness glasses are used for monitoring and error compensation with a classical monitoring approach is no longer possible for the whole filter. One optical monitoring technique that seems to maintain some form of error compensation, even when changing witness glass, is broadband optical monitoring, as it is possible to record the determined thicknesses as the layers are deposited and re-refine the target curves for remaining layers or recalculate the thicknesses of remaining layers. In addition, this method, if used properly, can, in some cases, provide greater accuracy for the thickness of deposited layers than monochromatic monitoring. In this paper, we discuss the process of determining a strategy for broadband monitoring with the goal of minimizing thickness errors for each layer of a given thin film design.
Mid-infrared silicon metasurfaces for near-field enhancement of molecular fingerprints
Authors: Li Minglu , Bai Ping , Yan Chang , Peng Siying
Published: February 2023

Mid-infrared dielectric metasurfaces are promising fundamental building blocks for integrated sensing with high sensitivity, compositional selectivity, and low loss. We have designed and fabricated a silicon metasurface with resonance properties in the 4∼5 µm mid-infrared region and a volume enhancement of up to 9 times. Benchmark FTIR characterizations of solutions of tungsten hexacarbonyl molecules showed a detection limit of 1 mg/mL without the usage of surface enrichment treatment. We further rationalize the detection limit of the molecules–nanostructure open interface with volume field enhancement analysis. Our results show that mid-infrared silicon metasurfaces may be a suitable platform for potential integration with microfluidic for in vivo detection.
Deep-red double-clad fiber laser at 717 nm
Authors: Kifle Esrom , Loiko Pavel , Berthelot Thibaud , Rault Thiphaine , Bodin Laurine , Pau Florence , Recoque Gilles , Georges Thierry , Camy Patrice
Published: February 2023

We report on a double-clad fiber laser operating on the 3P0 → 3F4 Pr3+ transition (in the deep-red spectral range) pumped by a GaN diode laser at ∼442 nm. It employs a 0.8-mol% PrF3-doped ZBLAN double-clad fiber with a 7.5-µm core, a double D-shaped inner cladding, and a length of 3.0 m. The laser delivers a maximum output power of 0.71 W at 716.7 nm with a slope efficiency of 9.0% (versus the launched pump power) and a laser threshold of 0.90 W. The laser emission is partially polarized. The laser performance is simulated providing a guideline for watt-level deep-red fiber laser sources.
Implementation of miniaturized modular-array fluorescence microscopy for long-term live-cell imaging
Authors: SON JEONGHWAN , Chen Qingyu , Jia Shu
Published: February 2023

Fluorescence microscopy imaging of live cells has provided consistent monitoring of dynamic cellular activities and interactions. However, due to the limited adaptability of current live-cell imaging systems, portable cell imaging system has been adapted by broad strategies, including miniaturized fluorescence microscopy. Here, we provide a protocol for the construction and operational process of miniaturized modular-array fluorescence microscopy (MAM). The MAM system is built in a portable size (15 cm × 15 cm × 3 cm) and provides in situ cell imaging inside an incubator with a subcellular lateral resolution (~3 μm). We demonstrated the improved stability of the MAM system with fluorescent targets and live HeLa cells, enabling long-term imaging for 12 hours without the need for external support or post-processing. We believe the protocol could guide scientists to construct a compact portable fluorescence imaging system and perform time-lapse in situ single-cell imaging and analysis.
Modeling the three-dimensional connectivity of in vitro cortical ensembles coupled to Micro-Electrode Arrays
Authors: Callegari Francesca , Brofiga Martina , Massobrio Paolo
Published: February 2023

Nowadays, in vitro three-dimensional (3D) neuronal networks are becoming a consolidated experimental model to overcome most of the intrinsic limitations of bi-dimensional (2D) assemblies. In the 3D environment, experimental evidence revealed a wider repertoire of activity patterns, characterized by a modulation of the bursting features, than the one observed in 2D cultures. However, it is not totally clear and understood what pushes the neuronal networks towards different dynamical regimes. One possible explanation could be the underlying connectivity, which could involve a larger number of neurons in a 3D rather than a 2D space and could organize following well-defined topological schemes. Driven by experimental findings, achieved by recording 3D cortical networks organized in multi-layered structures coupled to Micro-Electrode Arrays (MEAs), in the present work we developed a large-scale computational network model made up of leaky integrate-and-fire (LIF) neurons to investigate possible structural configurations able to sustain the emerging patterns of electrophysiological activity. In particular, we investigated the role of the number of layers defining a 3D assembly and the spatial distribution of the connections within and among the layers. These configurations give rise to different patterns of activity that could be compared to the ones emerging from real in vitro 3D neuronal populations. Our results suggest that the introduction of three-dimensionality induced a global reduction in both firing and bursting rates with respect to 2D models. In addition, we found that there is a minimum number of layers necessary to obtain a change in the dynamics of the network. However, the effects produced by a 3D organization of the cells is somewhat mitigated if a scale-free connectivity is implemented in either one or all the layers of the network. Finally, the best matching of the experimental data is achieved supposing a 3D connectivity organized in structured bundles of links located in different areas of the 2D network.
Detecting hand joint ankylosis and subluxation in radiographic images using deep learning: A step in the development of an automatic radiographic scoring system for joint destruction
Authors: Izumi Keisuke , Suzuki Kanata , Hashimoto Masahiro , Endoh Toshio , Doi Kentaro , Iwai Yuki , Jinzaki Masahiro , Ko Shigeru , Takeuchi Tsutomu , Kaneko Yuko
Published: February 2023

We propose a wrist joint subluxation/ankylosis classification model for an automatic radiographic scoring system for X-ray images. In managing rheumatoid arthritis, the evaluation of joint destruction is important. The modified total Sharp score (mTSS), which is conventionally used to evaluate joint destruction of the hands and feet, should ideally be automated because the required time depends on the skill of the evaluator, and there is variability between evaluators. Since joint subluxation and ankylosis are given a large score in mTSS, we aimed to estimate subluxation and ankylosis using a deep neural network as a first step in developing an automatic radiographic scoring system for joint destruction. We randomly extracted 216 hand X-ray images from an electronic medical record system for the learning experiments. These images were acquired from patients who visited the rheumatology department of Keio University Hospital in 2015. Using our newly developed annotation tool, well-trained rheumatologists and radiologists labeled the mTSS to the wrist, metacarpal phalangeal joints, and proximal interphalangeal joints included in the images. We identified 21 X-ray images containing one or more subluxation joints and 42 X-ray images with ankylosis. To predict subluxation/ankylosis, we conducted five-fold cross-validation with deep neural network models: AlexNet, ResNet, DenseNet, and Vision Transformer. The best performance on wrist subluxation/ankylosis classification was as follows: accuracy, precision, recall, F1 value, and AUC were 0.97±0.01/0.89±0.04, 0.92±0.12/0.77±0.15, 0.77±0.16/0.71±0.13, 0.82±0.11/0.72±0.09, and 0.92±0.08/0.85±0.07, respectively. The classification model based on a deep neural network was trained with a relatively small dataset; however, it showed good accuracy. In conclusion, we provided data collection and model training schemes for mTSS prediction and showed an important contribution to building an automated scoring system.
Isolation and characterization of halophilic and halotolerant fungi from man-made solar salterns in Pattani Province, Thailand
Authors: Wingfield Lakkhana Kanhayuwa , Jitprasitporn Ninadia , Che-alee Nureeda
Published: February 2023

The present study explored culturable halophilic and halotolerant fungi from man-made solar salterns in Pattani Province, Thailand. A total of 24 fungal isolates were discovered and characterized using morphological and molecular identification. Production of extracellular enzymes, secondary metabolites and mycoviruses was examined. Growth was observed in salinity and temperature ranges between 0%-20% and 28–40°C, respectively. Growth in different environmental conditions confirmed the halophilic or halotolerant nature of some strains. Fungal isolates were phylogenetically classified into seven different genera belonging to Aspergillus, Cladosporium, Curvularia, Diaporthe, Ectophoma, Fusarium and Penicillium. An enzymatic production test revealed that thirteen isolates could produce proteases and amylases at different levels. The presence of mycoviruses was detected in three isolates. Seventeen of the 24 isolates produced antimicrobial metabolites. The majority of these active isolates were identified as Aspergillus and Penicillium species. Crude extracts of the fungal mycelia and culture broths from these isolates had an inhibitory effect on both Gram-positive and Gram-negative bacteria and human pathogenic fungi. Research into fungi from saline environments could reveal fungal strains of biotechnological and industrial interest.
Phenotype switching in a global method for agent-based models of biological tissue
Authors: Bergman Daniel , Jackson Trachette L.
Published: February 2023

Agent-based models (ABMs) are an increasingly important tool for understanding the complexities presented by phenotypic and spatial heterogeneity in biological tissue. The resolution a modeler can achieve in these regards is unrivaled by other approaches. However, this comes at a steep computational cost limiting either the scale of such models or the ability to explore, parameterize, analyze, and apply them. When the models involve molecular-level dynamics, especially cell-specific dynamics, the limitations are compounded. We have developed a global method for solving these computationally expensive dynamics significantly decreases the computational time without altering the behavior of the system. Here, we extend this method to the case where cells can switch phenotypes in response to signals in the microenvironment. We find that the global method in this context preserves the temporal population dynamics and the spatial arrangements of the cells while requiring markedly less simulation time. We thus add a tool for efficiently simulating ABMs that captures key facets of the molecular and cellular dynamics in heterogeneous tissue.
Iconos y Sanctasanctórums de la patria: las galerías de ciudadanos ilustres en Catalunya y Balears (1871-1923)
Authors: Cao Costoya David
Published: February 2023

Son numerosos los municipios de Catalunya y Balears que disponían de colecciones de retratos de conciudadanos ilustres en el periodo de la Restauración. Se plantea aquí que pueden ser considerados como «lugares de memoria» y que actuaban como soportes de identidades territoriales (mayormente locales y regionales) e instrumentos de legitimación del rol preponderante de determinadas elites sociales en la colectividad. El estudio pretende ofrecer un marco interpretativo que permita comprender el fenómeno en su complejidad y aborda numerosos conjuntos icónicos a partir de una perspectiva comparada que atiende la mayor parte de las facetas fundamentales del objeto de estudio. La investigación invita a prestar mayor atención a los «espacios locales» y al rol de las ciudades en la producción de imaginarios autoreferenciales, proceso que es simultáneo a la proliferación de todo tipo de usos del pasado puestos al servicio de la construcción de las culturas regionales y nacionales. Los resultados del estudio apuntan a las galerías de ciudadanos ilustres en cuestión como instancias de consagración del rol referente que los intelectuales y profesionales cualificados pretendían despeñar en la colectividad, en un contexto de creciente presión democratizadora. Así mismo, indican que, a la vez que estos lieux de mémoire eran un mecanismo de dominio simbólico de la colectividad, actuaban como un dispositivo orientado a construir la reputación positiva de la población (y sus élites), con el fin de agenciar sus instituciones y poderes en el marco más amplio de la política provincial, regional y nacional. En definitiva, el artículo demuestra la voluntad y la capacidad que tuvieron las ciudades (incluso núcleos de tamaño modesto) de fomentar sus propias autoimágenes, e identifica los responsables y móviles de su producción.
El legitimista español (1869-1870). Prensa y política del carlismo en la primera fase del Sexenio Democrático
Authors: Verri Carlo
Published: February 2023

Con la revolución de septiembre de 1868 se instaura un régimen político en el que las libertades civiles se ven más respetadas, en particular la libertad de prensa, por lo cual se desarrollan desde el comienzo y de forma significativa varias tipologías de actividades editoriales, desde las satíricas hasta las políticas, vinculadas a las distintas corrientes que hacen valer sus propuestas con respecto a las instituciones que deberán remplazar a las viejas. También el carlismo se muestra más bien activo en el ámbito periodístico, cuando –por primera vez en su historia– toma el camino de la lucha pacífica, si bien sin abandonar la opción de una vía armada. Tras un apartado de contextualización y de análisis general de las características de la prensa carlista en el primer periodo del Sexenio, se pasa a un caso de estudio específico, tomando en consideración dos periódicos, uno continuación del otro: El Legitimista Español y La Legitimidad, no tan estudiados como los más conocidos La Esperanza, La Regeneración o El Pensamiento Español. La elección de estos dos periódicos permite profundizar en las cuestiones políticas a las que los carlistas han de enfrentarse en la primera parte del Sexenio, ya que su director es uno de los diputados tradicionalistas más activos en las Cortes: Cruz Ochoa, quien será, tras 1872, un convencido combatiente de la guerra civil.
«Mujeres en armas contra la Iglesia»: condenadas por delitos anticlericales durante la dictadura
Authors: Pérez Gómez María de los Llanos
Published: February 2023

La violencia anticlerical que se produjo como respuesta al golpe de Estado de 1936 ha sido analizada mayoritariamente en clave masculina. La historiografía ha atribuido a los hombres el papel principal de verdugos en las acciones iconoclastas y clerófobas producidas en la retaguardia republicana. Aunque resulta incuestionable que fueran en su mayor parte hombres los que participaron en estas acciones, estos estudios también han insistido en la «pasividad» con la que actuaron las mujeres, que han sido representadas como figuras impotentes que observaban pasivamente, sorprendidas, mientras los protagonistas masculinos actuaban. Su participación en estos actos de violencia ha sido incluso comparada directamente con la que llevaron a cabo los niños. Sin embargo, con el final de la guerra, las mujeres también fueron acusadas por la dictadura de participar en esta violencia anticlerical, como se refleja en los juicios sumarísimos dictados por los tribunales militares franquistas. Por ello, en este texto, además de tratar de indagar en la actuación femenina en estas acciones, se analizará la violencia que el Régimen ejerció sobre las mujeres, a las que procesó, encarceló y condenó, en algunos casos a la pena máxima, por su actuación contra la Iglesia en el verano de 1936. Un análisis pormenorizado de estos juicios nos mostrará cuáles fueron los delitos que la dictadura les atribuyó a las mujeres y si en ellos se tuvo en cuenta su género a la hora de ser procesadas por su participación en unos actos anticlericales que han sido, y que siguen siendo considerados de hombres.
Monuments, escultures i museus en els espais històrics de la Batalla de l’Ebre. Les aportacions del Grup «Didáctica del Patrimoni» de la Universitat de Barcelona
Authors: Sospedra-Roca Rafel , Hernàndez-Cardona Francesc Xavier , Boj-Cullell Isabel , Hernàndez-Pongiluppi Mar
Published: February 2023

La Batalla de l’Ebre (1938) va ser la més decisiva de la Guerra Civil espanyola. La desfeta de l’Exèrcit Popular va provocar l’ocupació de Catalunya i la victòria definitiva de les forces del general Franco sobre la República espanyola. Els vencedors van ubicar sobre el camp de batalla monuments per escenificar la seva victòria, però les accions de patrimonialització van tenir un desenvolupament limitat, mentre que la II Guerra Mundial i el seu desenllaç van obrir perspectives incertes per al règim del general Franco. La mort del dictador l’any 1975 va provocar canvis polítics a Espanya, i els espais històrics de la Batalla de l’Ebre van conèixer noves intervencions a l’entorn del seu patrimoni, subsidiàries dels imaginaris socials i polítics del procés de democratització. Nous monuments i instal·lacions museals convidaven a una interpretació de la batalla compatible amb l’imaginari de reconciliació desenvolupat pel nou règim constitucional. Dècades després dels combats, la batalla de l’Ebre continuava, però ara la pugna s’establia entre models i accions per fixar la memòria al territori, a partir d’intervencions patrimonials, museus, monuments i escultures. En el context d’emergència democràtica de principis del segle XXI, les iniciatives de la societat civil, sumades a les dinàmiques de recerca i socialització del coneixement impulsades en clau d’història pública i arqueologia pública, obrien noves perspectives en la recuperació d’una memòria republicana de la batalla. En aquest context destaquen les iniciatives del grup de recerca «Didàctica del Patrimoni» (DIDPATRI) de la Universitat de Barcelona. L’estudi aproxima les diferents fases d’apropiació, en clau de memòria històrica, del camp de batalla de l’Ebre, i les iniciatives i casuístiques principals de patrimonialització generades, al seu entorn, en els diferents moments històrics.
BAR SHUALI, Jonathan Jacobo. (2022) Breve historia del Ejército Napoleónico. La Grande Armée de Napoleón y sus aliados. Madrid, Nowtilus, 377 pp.
Authors: Cañas de Pablos Alberto
Published: February 2023

BAR SHUALI, Jonathan Jacobo. (2022) Breve historia del Ejército Napoleónico. La Grande Armée de Napoleón y sus aliados. Madrid, Nowtilus, 377 pp.