bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical vortex switch based on multiplexed volume gratings with high diffraction efficiency
Authors: Zhao Jingyin , Jin Yunxia , Kong Fanyu , He Dongbing , Cao Hongchao , Hao Wang , Wu Yubo , Shao Jianda
Published: September 2021

Systems of controllable orbital angular momentum (OAM) require more compact, higher conversion efficiency and more tolerable wavelength or polarization. We introduce an optical vortex switch based on a multiplexed volume grating (MVG). The MVG recorded in a piece of photo-thermo-refractive (PTR) glass exhibits high diffraction efficiency (DE, also known as conversion efficiency in transporting), sensitive angular selectivity, and polarization-insensitivity. The effects of the incident divergence angle and polarization on the DE and the far-field diffraction profiles are demonstrated and investigated. It turns out that the divergence angle of the probe beam can greatly affect the DE. The fluctuation of the DE caused by polarization variation is less than 1.59%. This switch can be potentially applied in vortex tweezers, optical communication, and high power systems.
Angle-resolved polarized Raman spectra of the basal and edge plane of MoS2
Authors: Liu Yi , Zhang Yu-Fan , Jin Shan , Li Si-Pu , Yang Ming-Ming , Kong Xiang-Rui , Dang Wei , Li Xiao-Li , Cong Ri-Dong
Published: September 2021

Angle-resolved polarized (ARP) Raman spectroscopy can be utilized to characterize the Raman modes of two-dimensional layered materials based on crystal symmetry or crystal orientation. In this paper, the polarization properties of

E
1

2
g

and A1g modes on the basal plane and edge plane of high purity 2H-MoS2 bulk crystal grown by chemical vapor transport (CVT) method were investigated by ARP Raman spectroscopy. The I and II type ARP Raman spectroscopy with four kinds of polarization configurations: αY, αX, βY, and βX were used to explore the intensity dependence of

E
1

2
g

and A1g modes at different planes on the polarization direction of incident/scattered light. The results show that the

E
1

2
g

and A1g modes exhibit different polarization properties dependent on the polarization of the incident laser and the in-plane rotation of the sample at different planes. The experimental results were confirmed and analyzed through theoretical calculation. Our work sheds light on the intriguing effect of the subtle atomic structure in stacked MoS2 layers on the resulting ARP Raman properties. This provides a reference for the study of other two-dimensional layered crystalline materials by ARP Raman spectroscopy.
Femtosecond laser point-by-point inscription of an ultra-weak fiber Bragg grating array for distributed high-temperature sensing
Authors: Xu Baijie , He Jun , Du Bin , Xiao Xunzhou , Xu Xizhen , Fu Cailing , He Jia , Liao Changrui , Wang Yiping
Published: September 2021

Ultra-weak fiber Bragg grating (UWFBG) arrays are key elements for constructing large-scale quasi-distributed sensing networks for structural health monitoring. Conventional methods for creating UWFBG arrays are based on in-line UV exposure during fiber drawing. However, the UV-induced UWFBG arrays cannot withstand a high temperature above 450 °C. Here, we report for the first time, to the best of our knowledge, a new method for fabricating high-temperature-resistant UWFBG arrays by using a femtosecond laser point-by-point (PbP) technology. UWFBGs with a low peak reflectivity of ∼ - 45 dB (corresponding to ∼ 0.0032%) were successfully fabricated in a conventional single-mode fiber (SMF) by femtosecond laser PbP inscription through fiber coating. Moreover, the influences of grating length, laser pulse energy, and grating order on the UWFBGs were studied, and a grating length of 1 mm, a pulse energy of 29.2 nJ, and a grating order of 120 were used for fabricating the UWFBGs. And then, a long-term high-temperature annealing was carried out, and the results show that the UWFBGs can withstand a high temperature of 1000 °C and have an excellent thermal repeatability with a sensitivity of 18.2 pm/°C at 1000 °C. A UWFBG array consisting of 200 identical UWFBGs was successfully fabricated along a 2 m-long conventional SMF with an interval of 10 mm, and interrogated with an optical frequency domain reflectometer (OFDR). Distributed high-temperature sensing up to 1000 °C was demonstrated by using the fabricated UWFBG array and OFDR demodulation. As such, the proposed femtosecond laser-inscribed UWFBG array is promising for distributed high-temperature sensing in hash environments, such as aerospace vehicles, nuclear plants, and smelting furnaces.
Automated optical monitoring wavelength selection for thin-film filters
Authors: Zideluns Janis , Lemarchand Fabien , Arhilger Detlef , Hagedorn Harro , Lumeau Julien
Published: September 2021

In this paper we study the wavelength selection process for optical monitoring of thin film filters. We first discuss the technical limitations of monitoring systems as well as the criteria defining the sensitivity of different wavelengths to thickness errors. We then present an approach that considers the best monitoring wavelength for each individual layer with a monitoring strategy selection process that can be fully automated. We finally validate experimentally the proposed approach on several optical filters of increasing complexity. Optical interference filters with close to theoretical performances are demonstrated.
3DM: deep decomposition and deconvolution microscopy for rapid neural activity imaging
Authors: Cho Eun-Seo , Han Seungjae , Lee Kang-Han , Kim Cheol-Hee , Yoon Young-Gyu
Published: September 2021

We report the development of deep decomposition and deconvolution microscopy (3DM), a computational microscopy method for the volumetric imaging of neural activity. 3DM overcomes the major challenge of deconvolution microscopy, the ill-posed inverse problem. We take advantage of the temporal sparsity of neural activity to reformulate and solve the inverse problem using two neural networks which perform sparse decomposition and deconvolution. We demonstrate the capability of 3DM via in vivo imaging of the neural activity of a whole larval zebrafish brain with a field of view of 1040 µm × 400 µm × 235 µm and with estimated lateral and axial resolutions of 1.7 µm and 5.4 µm, respectively, at imaging rates of up to 4.2 volumes per second.
Imaging Mueller matrix ellipsometry with sub-micron resolution based on back focal plane scanning
Authors: Chen Chao , Chen Xiuguo , Wang Cai , Sheng Sheng , Song Lixuan , Gu Honggang , Liu Shiyuan
Published: September 2021

The development of nanotechnology and nanomaterials has put forward higher requirements and challenges for precision measurement or nanometer measurement technology. In order to cope with this situation, a new type of imaging Mueller matrix ellipsometer (IMME) has been developed. A back focal plane scanning method is designed to make the IMME have the ability to measure multiple incident angles. A two-step calibration method is proposed to ensure the measurement accuracy of IMME. After calibration, the IMME can achieve measurement with wavelengths from 410 nm to 700 nm and incident angles from 0° to 65°. The lateral resolution of the IMME is demonstrated to be 0.8 μm over the entire measurement wavelength range. In addition, a Hadamard imaging mode is proposed to significantly improve the imaging contrast compared with the Mueller matrix imaging mode. Subsequently, the IMME is applied for the measurement of isotropic and anisotropic samples. Experimental results have demonstrated that the proposed IMME has the ability to characterize materials with complex features of lateral micron-distribution, vertical nano-thickness, optical anisotropy, etc., by virtue of its advantages of high lateral resolution and high precision ellipsometric measurement.
Secure quantum secret sharing without signal disturbance monitoring
Authors: Gu Jie , Xie Yuan-Mei , Liu Wen-Bo , Fu Yao , Yin Hua-Lei , Chen Zeng-Bing
Published: September 2021

Quantum secret sharing (QSS) is an essential primitive for the future quantum internet, which promises secure multiparty communication. However, developing a large-scale QSS network is a huge challenge due to the channel loss and the requirement of multiphoton interference or high-fidelity multipartite entanglement distribution. Here, we propose a three-user QSS protocol without monitoring signal disturbance, which is capable of ensuring the unconditional security. The final key rate of our protocol can be demonstrated to break the Pirandola-Laurenza-Ottaviani-Banchi bound of quantum channel and its simulated transmission distance can approach over 600 km using current techniques. Our results pave the way to realizing high-rate and large-scale QSS networks.
All-dielectric thin films based on single silicon materials for angle-insensitive structural colors
Authors: Feng Kun , Li Qingyuan , Liu Jintong , Wang Yusi , Chen Nan , Li Yankai , Bu Yikun
Published: September 2021

Here we demonstrate a red structural color of a multilayer structure made of all silicon-based materials. By using amorphous silicon (a-Si) and silicon dioxide (

S
i
O

2

) with a large difference in the refractive index, high reflection efficiency can be achieved with only a few layers. The anti-reflection unit composed of top silicon monoxide (SiO) and

S
i
O

2

layers can significantly reduce the reflection intensity of the non-target wavelengths to ensure that the device has good color saturation. The selective absorption of SiO and a-Si layers can further improve the color saturation. By reasonably controlling the thickness of the highly absorbing materials, the device has good angular insensitivity at an incident angle of 0°–60°. Furthermore, the angle-insensitive blue and yellow structural colors are also realized based on the all silicon design idea. This scheme is simple in structure and capable of efficient mass production. This method has enormous potential for diverse applications in display, colorful decoration, anti-counterfeiting, and so forth.
Broadband circularly polarized thermal radiation from magnetic Weyl semimetals
Authors: Wang Yifan , Khandekar Chinmay , Gao Xingyu , Li Tongcang , Jiao Dan , Jacob Zubin
Published: September 2021

We numerically demonstrate that a planar slab made of magnetic Weyl semimetal (a class of topological materials) can emit high-purity circularly polarized (CP) thermal radiation over a broad mid- and long-wave infrared wavelength range for a significant portion of its emission solid angle. This effect fundamentally arises from the strong infrared gyrotropy or nonreciprocity of these materials, which primarily depends on the momentum separation between Weyl nodes in the band structure. We clarify the dependence of this effect on the underlying physical parameters and highlight that the spectral bandwidth of CP thermal emission increases with increasing momentum separation between the Weyl nodes. We also demonstrate, using the recently developed thermal discrete dipole approximation (TDDA) computational method, that finite-size bodies of magnetic Weyl semimetals can emit spectrally broadband CP thermal light, albeit over smaller portion of the emission solid angle compared to the planar slabs. Our work identifies unique fundamental and technological prospects of magnetic Weyl semimetals for engineering thermal radiation and designing efficient CP light sources.
Soliton molecules in femtosecond fiber lasers: universal binding mechanism and direct electronic control
Authors: Nimmesgern Luca , Beckh Cornelius , Kempf Hannes , Leitenstorfer Alfred , Herink Georg
Published: September 2021

Sequences of ultrashort pulses form the basis of extremely precise laser applications ranging from femtosecond spectroscopy, to material microprocessing, to biomedical imaging. Dynamic patterns of temporal solitons—termed “soliton molecules”—inside mode-locked cavities provide yet unexplored means for generating reconfigurable arrangements of ultrashort pulses. Here, we demonstrate the external control of solitonic bound states in widespread erbium-doped fiber lasers via direct electronic modulation of the semiconductor pump source. This straightforward approach allows for switching between discrete soliton doublet states of picosecond separations, employing and relying on laser-intrinsic soliton interactions. We analyze the externally induced dynamics based on real-time switching data acquired by time-stretch dispersive Fourier transform spectroscopy and identify a universal bound-state formation mechanism different from broadly considered models. Owing to the ease of implementation and its intrinsic tunability, our control scheme is readily applicable to various laser platforms enabling, e.g., rapid multipulse measurements and tailored nonlinear light–matter interactions.
Prefrontal cortical activity predicts the occurrence of nonlocal hippocampal representations during spatial navigation
Authors: Yu Jai Y. , Frank Loren M.
Published: September 2021

The receptive field of a neuron describes the regions of a stimulus space where the neuron is consistently active. Sparse spiking outside of the receptive field is often considered to be noise, rather than a reflection of information processing. Whether this characterization is accurate remains unclear. We therefore contrasted the sparse, temporally isolated spiking of hippocampal CA1 place cells to the consistent, temporally adjacent spiking seen within their spatial receptive fields (“place fields”). We found that isolated spikes, which occur during locomotion, are strongly phase coupled to hippocampal theta oscillations and transiently express coherent nonlocal spatial representations. Further, prefrontal cortical activity is coordinated with and can predict the occurrence of future isolated spiking events. Rather than local noise within the hippocampus, sparse, isolated place cell spiking reflects a coordinated cortical–hippocampal process consistent with the generation of nonlocal scenario representations during active navigation.
Protein structural features predict responsiveness to pharmacological chaperone treatment for three lysosomal storage disorders
Authors: Woodard Jaie , Zheng Wei , Zhang Yang
Published: September 2021

Three-dimensional structures of proteins can provide important clues into the efficacy of personalized treatment. We perform a structural analysis of variants within three inherited lysosomal storage disorders, comparing variants responsive to pharmacological chaperone treatment to those unresponsive to such treatment. We find that predicted ΔΔG of mutation is higher on average for variants unresponsive to treatment, in the case of datasets for both Fabry disease and Pompe disease, in line with previous findings. Using both a single decision tree and an advanced machine learning approach based on the larger Fabry dataset, we correctly predict responsiveness of three Gaucher disease variants, and we provide predictions for untested variants. Many variants are predicted to be responsive to treatment, suggesting that drug-based treatments may be effective for a number of variants in Gaucher disease. In our analysis, we observe dependence on a topological feature reporting on contact arrangements which is likely connected to the order of folding of protein residues, and we provide a potential justification for this observation based on steady-state cellular kinetics.