bluuebunny/crossref_metadata_2025 huggingface dataset:
Integral Imaging Combined with Acoustic Trapping
Authors: Mohsenvand Kooshan , Carnicer Artur , Marmiroli Benedetta , Moradi Ali-Reza
Published: November 2023

For several 3D imaging applications the object requires immobilization. Here, in analogy to digital holography and optical trapping combination for microscopic objects, we introduce integral imaging and acoustic trapping integrated systems for mesoscopic and beyond objects.
Real-time wide-range light-field camera using aerial imaging
Authors: Kameyama Masanari , Kono Shoma , Kawakita Masahiro
Published: November 2023

We propose a novel light-field camera that uses aerial images of objects and a lens array. The prototype camera can capture light rays of moving objects with an angular range greater than 30°.
Three-dimensional event imaging by multiplexing stereo channels on a single Dynamic Vision Camera
Authors: Ilani Raviv , Stern Adrian
Published: November 2023

Classical 3D imaging approaches of using two or more synchronized event-based cameras may be cost-prohibitive due to their high cost. This work proposes a new simple and practical 3D imaging technique using a single stationary camera.
Multi-focus imaging in Fluorescence Microscopy and Augmented Reality
Authors: Alonso Julia R.
Published: November 2023

We present our recent advances regarding multi-focus imaging for 3D visualization applied to fluorescence microscopy and to augmented reality devices.
Monte Carlo simulation of alpha emission detection system using air nitrogen scintillation
Authors: Omika S. , Ueno S. , Kume N. , Nakai Y. , Okazaki K. , Sumita A. , Miyadera H. , Sumitani M. , Miyahara Y. , Takagi J.
Published: November 2023

An alpha emission detector was developed to monitor alpha contamination in the buildings of Fukushima Daiichi Nuclear Power Station during the decommissioning processes. To confirm usable conditions of the α-ray detection system under the high dose environments, Monte Carlo simulations were carried out to evaluate the amount of photons emitted by the α-ray. The results agreed within a factor of 2 from the measured values.
Comparison of Non-contact Air Temperature Imaging Technique using Parallel Phase-shifting Digital Holography with Thermocouples
Authors: Kumon Yuki , Inoue Tomoyoshi , Nishio Kenzo , Xia Peng , Kumar Manoj , Matoba Osamu , Rajput Sudheesh K. , Awatsuji Yasuhiro
Published: November 2023

We experimentally compared the air temperatures measured by non-contact imaging technique using parallel phase-shifting digital holography with those measured with a thermocouple. This study revealed that the technique has a faster thermal response than thermocouples.
Floating multi-view three-dimensional display using a digital micro-mirror and dihedral corner reflector array
Authors: Kheibarihafshejani Sahar , Park Jae-Hyeung
Published: November 2023

A floating multi-view display using a digital micro-mirror (DMD) and a dihedral corner reflector ( DCRA) is presented. Multiple perspectives are projected to the corresponding viewpoints via time-multiplexing, enabling viewers to see a mid-air floating image.
Simple method for microscope lens calibration using grid lines.
Authors: Cruz Maria-Luisa
Published: November 2023

We propose a simple method to calibrate a microscope lens using a grid lines pattern. We get four calibration patterns from each image, reducing the number of required images. In the final result, most of the spherical aberration is eliminated.
Generation of vector Bessel modes using spiral axicon hologram
Authors: Baliyan Mansi , Nishchal Naveen K.
Published: November 2023

In this paper, homogeneous as well as spatially varying polarization distributions of Bessel beams is studied using spiral axicon hologram displayed on spatial light modulator. Theoretical and experimental results for scalar and vector Bessel beams are presented.
Numerical Simulation of Dynamic High-order Viewing Zone Switching in Complex Light Modulation by Three-phase Amplitude Macro-pixel
Authors: Na Sehwan , Lee Jonghyun , Park Shin-Woong , Kim Hwi
Published: November 2023

We studied a technique for extending the viewing zone of complex light modulation using three-phase amplitude macro-pixels. The proposed method offers a key feature of dynamically switching the complex optical field to a high-order viewing zone.
Bayesian optimization for autoalignment of an x-ray focusing system
Authors: Kandel Saugat , Rebuffi Luca , Cha Wonsuk , Harder Ross J. , Shi Xianbo , Highland Matthew J. , Frith Matthew G. , Cherukara Mathew J.
Published: November 2023

We describe a multi-objective Bayesian Optimization routine to automatically align and stabilize an x-ray focusing system. We develop our technique in an ultra-realistic digital twin and implement it in a hard-x-ray synchrotron beamline.
Density Reconstruction from Noisy Radiographs using an Attention-based Transformer Network
Authors: Serino Daniel A. , Klasky Marc , Burby Joshua W. , Schei Jennifer L.
Published: November 2023

A trained attention-based transformer network can robustly recover density fields from a sequence of features derived from radiographic images corrupted with blur, scatter, and noise. This approach is demonstrated on imploding shell hydrodynamic simulations.
In situ measurement of chromatic dispersion in an optical hypertelescope: a laboratory demonstration
Authors: Allured Ryan , Ashcom Jonathan B. , Chapnik Philip
Published: November 2023

Optical interferometry is a technique capable of achieving better
spatial resolution than the world’s largest monolithic telescopes at a
fraction of the cost. Most interferometer architectures split the
imaging bandwidth into a number of channels in order to prevent image
degradation due to a large spectral bandwidth. An optical
hypertelescope permits a much broader spectral bandwidth on a single
channel than a conventional interferometer. However, a broader
spectral bandwidth becomes more sensitive to differential chromatic
dispersion, and this dispersion must be measured and corrected in
order to maintain a high signal-to-noise ratio. A prototype dispersion
measurement system is presented that is capable of measuring chromatic
dispersion in an eight aperture hypertelescope. The optical design,
calibration, data acquisition, and dispersion measurement process are
described in detail. This system is capable of measuring differential
dispersion to better than λ/100RMS and is scalable to a system with an
order of magnitude more apertures.
Precision tailoring of laser beam propagation in a single crystalline diamond tool for in situ laser-assisted diamond turning
Authors: Hu Wangjie , Li Zengqiang , Zhao Xuesen , Sun Tao , Zhang Junjie
Published: November 2023

The characteristics of laser beam propagation within a diamond tool critically influence the applied thermal softening capability of in situ laser-assisted diamond turning (In-LAT). In the present work, we perform optical geometric analysis, optical simulation and experimental validation to propose a novel diamond tool configuration for precisely tailoring laser beam propagation in In-LAT. First, the characteristics of laser beam propagation in the current In-LAT diamond tool are theoretically and experimentally explored. Second, according to the issues discovered in the current In-LAT diamond tool, an improved tool configuration based on the total internal reflection of a laser beam within the diamond tool is proposed, aiming for promoting refraction of the laser beam from the rake face of the diamond tool as well as eliminating the reflection of laser beam to tool holder. Finally, the optimization of laser beam incident position is carried out for achieving the superior profile and intensity of the emitted laser spot. Current work provides rational laser beam propagation for improving the thermal-softening capability of an In-LAT diamond tool.
Portable contactless caliper
Authors: Boonmeeprakob Konthee , Phanpumnak Arinchaya , Punwong Chutintorn , Chana Sureerat , Thavarungkul Panote , Kanatharana Proespichaya , Buranachai Chittanon
Published: November 2023

This work presents a portable optical meter for noncontact thickness measurement. The
device shines a focused laser light on a thin and transparent sample,
resulting in an interference between light reflecting from the top and
from the bottom surface, and the interfering pattern is recorded by a
linear sensor array before data analysis with an Arduino
microcontroller. The device produced accurate thickness values from
glass cover slips and transparent plastic sheets within a fraction of
a second per measurement. Additionally, the sample’s refractive index
is not required a priori. Therefore, it
has a high potential to be of use in real-time quality control in
transparent thick-film coating and manufacturing.
Anisotropic intensity diffraction tomography
Authors: Xu Shiqi , Dai Xiang , Yang Xi , Lee Kyung Chul , Kreiss Lucas , Zhou Kevin C. , Kim Kanghyun , Chaware Amey , Horstmeyer Roarke
Published: November 2023

We present a new non-scanning technique to reconstruct tomographic permittivity metrics of anisotropy samples from polarized intensity measurements. We apply the method to image both calibration targets and 3D tissue samples.
Differential structured illumination microscopy for high-throughput, wide-field 3D computational phase imaging
Authors: Matlock Alex , Yaqoob Zahid , So Peter T. C.
Published: November 2023

We present differential structured illumination microscopy (dSIM), a new modality utilizing differential image acquisitions with darkfield-based patterned illumination to provide high-resolution, large field-of-view 3D computational phase imaging with linear inverse scattering models.
EUV diffractive imaging in reflection for wafer metrology using HHG source and automatic differentiation based ptychography
Authors: Weerdenburg Sven , Shao Yifeng , Horsten Roland , Coene Wim
Published: November 2023

We report on a reflective ptychographic imaging system with an EUV high harmonic generation setup at 18 nm. Complex-valued multi-wavelength, multi-mode ptychographic reconstructions, utilizing automatic differentiation, of gold-titanium patterned samples can be demonstrated with 50-by-100 nanometers resolution.
Spectral DiffuserScope - Computational Snapshot Hyperspectral Imager for Microscopy
Authors: Aggarwal Neerja , Markley Eric , Raniwala Yashovardhan , Houck William D. , Lee Kyung Chul , Bae Junghyun , Baek Nakkyu , Park Wook , Lee Seung Ah , Waller Laura
Published: November 2023

We introduce a computational snapshot hyperspectral imager for benchtop microscopy. The compact device uses a diffuser and spectral filter array to multiplex spatio-spectral information into a 2D measurement, then reconstructs the datacube via compressed sensing.
Computational multi-scale imaging for widefield aberration-corrected Ophthalmoscopy
Authors: Terry Joel , Carles Guillem , Harvey Andrew R
Published: November 2023

The maximum number of pixels that can be recorded in a retinal imager is limited by ocular aberrations to about 5Mpixels. We report a new multi-scale concept able to yield diffraction-limited images with 50MPixels space-bandwidth product.
Hydrodynamic parameter estimation using statistical machine learning for dynamic radiography
Authors: De Soumi , Klasky Marc , Korobkin Oleg , GS Sidharth , Xu Xiaojian
Published: November 2023

Characterization of material properties of objects undergoing strong deformations is an important task in material science. Using neural networks with dynamic features extracted from radiographic projections we obtain physics parameter estimates and characterize materials.
Coherent diffractive imaging for dynamic printing
Authors: Guo Zhen , Liu Zhiguang , Pang Subeen , Zhang Fucai , Barbastathis George
Published: November 2023

We present a dynamic projection lithography system integrated with a coherent diffractive imaging module. An iterative phase retrieval algorithm is employed for reconstruction. Our experiment successfully reconstructs the printing process over 450 seconds.
RGB Photometric Model for Optical/Neural Network Co-Design
Authors: Dufraisse Marius , Trouvé-Peloux Pauline , Volatier Jean-Baptiste , Champagnat Frédéric
Published: November 2023

We propose to relate a photometric model of imaging sensors to optical parameters, including sensor noise and non-linearities in optics/neural-network co-design. We apply it in extension of the depth of field examples.
Shift-variant PSF characterization of DOE-based imaging systems via implicit neural representations
Authors: Morales-Norato David , Arguello Henry , Rueda-Chacón Hoover
Published: November 2023

This work proposes to learn implicit neural representations of shift-variant PSFs for optical imaging systems that use diffractive optical elements. Results show that the proposed method is able to characterize shift-variant PSFs from sparse samples.
SW-DORT: Imaging Through Scattering Media Using Synthetic Wavelengths with DORT
Authors: Lee Michael Joseph , Sun Jipeng , Cossairt Oliver
Published: November 2023

In this paper, we proposed a robust approach to image through scattering media without explicitly modeling the aberrating media by applying synthetic wavelengths to the DORT method.
Wafer inspection through reflection mode super-resolution topography
Authors: Lee Hojun , Sung Jangwoon , Park Seungbeom , Shin Junho , Kim Hyungjin , Kim Wookrae , Lee Myungjun
Published: November 2023

We propose an innovative lens-less imaging system for wafer surface inspection using speckle illumination in reflection mode. Our proposed system provides 3D imaging capability while enhancing both the resolution and the field-of-view.
Rolling Shutter Speckle Plethysmography for Pulsatile Blood Flow Analysis
Authors: Lee Yujin , Byun Sangjun , Yi Changyoon , Jung Jaewoo , Lee Seung Ah
Published: November 2023

We propose a novel method of speckle plethysmography using rolling shutter image sensors to measure blood flow dynamics. By utilizing temporal analysis, our technique enables the accurate measurement of SPG waveforms.
Multi-scale speckle-plethysmography with a multi-camera array microscope
Authors: Xu Shiqi , Yang Xi , Kim Kanghyun , Reamey Paul , Cook Clare , Lee Kyung Chul , Saliu Veton , Harfouche Mark , Bègue Aurélien , Horstmeyer Roarke
Published: November 2023

We present a high spatial resolution speckle-plethysmography (SPG) system with 0.3 gigapixels per snapshot, using a recently developed parallelized array microscope. We demonstrate an SPG video monitoring physarum cytoplasmic streaming through a thin scattering layer across a wide field of view.
Toward Multimodal Functionalized Markerless Imaging: Extensions of Tomographic Diffraction Microscopy
Authors: Verrier Nicolas , Debailleul Matthieu , Haeberlé Olivier
Published: November 2023

Tomographic Diffraction Microscopy (TDM) is an invaluable tool in markerless 3D imaging of biosamples. However, TDM lacks from information selectivity compared to other techniques. This presentation will discuss extensions of TDM to other imaging contrasts, which, combined with the refractive index information, allows bringing back selectivity.
Improvement for the Display Quality of a Single Binary Computer-Generated Hologram
Authors: Liu Jung-Ping , Tsai Chen-Ming
Published: November 2023

Binary computer-generated holograms (BCGHs) own the advantage of small size and can be directly displayed on a binary spatial light modulator. However, the display quality of a single BCGH is usually low due to the limited degrees of freedom. Here we introduce a new BCGH algorithm to achieve high display quality by a single BCGH.
Leveraging High-Order Diffractions of Phase Hologram using Pupil Function for Enhanced Holographic Display
Authors: Choi Myeong-Ho , Park Jae-Hyeung
Published: November 2023

We present a pupil-dependent optimization technique of computer-generated hologram (CGH). The optimization process is implemented by comparing target and reconstructed image with a pupil function applied to the Fourier plane of the CGH with high-order diffractions.
High-Density Scintillating Glasses for Integrating-mode Particle Radiography
Authors: Robertson Daniel , Stolen Ethan , Fullerton Ryan , Akgun Ugur , Fekete Charles-Antoine Collins , Beddar Sam
Published: November 2023

High-density glass scintillators may improve integrating-mode proton radiography detectors by improving resolution and decreasing detector size. Five new scintillators were evaluated with measurements and Monte Carlo simulations, characterizing light output, ionization quenching, and spatial resolution.
Polygon-based holograms production pipeline: from 3D modeling to optical reconstruction
Authors: Wang Fan , Blinder David , Shiomi Harutaka , Ito Tomoyoshi , Shimobaba Tomoyoshi
Published: November 2023

We have built a comprehensive production pipeline for polygon-based holograms with advanced acceleration, shading rendering, and occlusion-culling algorithms. The optical setup used for reconstruction serves as the end of the pipeline and confirms its results.
Wigner Inverse Transform Based Computer-generated Hologram Synthesis from Light Field Obtained by Neural Network
Authors: Min Dabin , Min Kyosik , Park Jae-Hyeung
Published: November 2023

In this paper, we report a Wigner inverse transform based computer-generated hologram (WCGH) synthesis from light field obtained by neural networks (NN). Two NN, i.e., single image to light field network and neural radiance fields (NeRF) are used for the hologram synthesis and the results are discussed.
Multi-probe Radiography for Dynamic Condensed Matter Experiments
Authors: Batha S. H. , Reinovsky R. E. , Alvarado-Alvarez M. , Broughton D. P. , Huang C. K. , Junghans A. , Schmidt T. R. , Wang Z. , Wolfe B.T. , Wong C. -S.
Published: November 2023

Multi-probe, point-projection radiography is explored, potentially using petawatt laser sources of x-rays, protons, neutrons and electrons, to diagnose dynamic, condensed matter experiments across experimental scales from single physics experiments to complex engineered systems.
Speckle Reduction in Phase extracted from off-axis Digital Holography with Transport of Intensity
Authors: Mirando Amal , Banerjee Partha P.
Published: November 2023

A method for speckle noise suppression to improve the accuracy during phase retrieval is proposed. This utilizes a series of decorrelated holograms by simultaneously varying the linear polarization state of the object and reference beams.
Videography based on computational optical scanning holography
Authors: Yoneda Naru , Ipus Erick , Ordóñez Luis , Lenz Armin J. M. , Martínez-León Lluís , Matoba Osamu , Tajahuerce Enrique
Published: November 2023

Computational optical scanning holography (COSH), OSH using a spatial light modulator (SLM), has been proposed to realize a simple OSH setup. COSH, however, has yet to be applied for imaging a moving object due to the limitation of the frame rate of SLMs. In this research, a moving object is imaged by applying a fast SLM to COSH. The experimental result indicates the proposed method can take images with a frame rate of 1.25 Hz.
Fluorescence self-interference digital holography with the capability of adaptive three-dimensional microscopic imaging
Authors: Wan Yuhong , Man Tianlong , Zhang Wenxue
Published: November 2023

Details on the guide-star-free interferometric wavefront sensing, correction, and optimization mechanisms in the spatial incoherent system are demonstrated, followed by our recent progress in 3D non-scanning adaptive microscopic imaging based on fluorescence self-interference digital holography.
Tomographic phase microscopy by 3D Zernike polynomials
Authors: Memmolo Pasquale , Pirone Daniele , Giugliano Giusy , Bianco Vittorio , Miccio Lisa , Ferraro Pietro
Published: November 2023

The three-dimensional version of Zernike polynomials are used to encode single-cell phase contrast tomograms, allowing an efficient tomographic data representation, compression and reconstruction with negligible information loss.
Sample Transmittance and Camera Bit-Depth Effects in Single-Shot Digital Holographic Microscopy
Authors: Buitrago-Duque Carlos , García-Sucerquia Jorge , Martínez-Corral Manuel , Sánchez-Ortiga Emilio
Published: November 2023

The effect of sample transmittance and bit depth of digital cameras on quantitative phase imaging in off-axis digital holographic microscopy is studied. Adequate processing of transmittances below 1 % in a 16-bit-depth camera is shown.
Deep learning aided Variational Hilbert Quantitative Phase Imaging
Authors: Cywińska Maria , Patorski Krzysztof , Trusiak Maciej
Published: November 2023

This work discusses the use of neural networks to determine the result of quantitative phase measurement via 2D Hilbert transform. We propose two approaches for solving fringe pattern-based phase demodulation problem aiding quantitative phase imaging technology.
3D Object Reconstruction Using Deep Learning Coherence Holography (DCH)
Authors: Trieu Quang , Nehmetallah George
Published: November 2023

We propose a novel reconstruction method for coherence holography using neural networks. We developed a cGAN to reconstruct a 3D complex object from a single interferogram, which yields excellent results in terms of accuracy and time.
Diffraction calculation using low-quantization signals
Authors: Shimobaba Tomoyoshi , Tahara Tatsuki , Wang Fan , Shiomi Harutaka , Blinder David , Hara Takayuki , Nishitsuji Takashi , Shiraki Atsushi , Ito Tomoyoshi
Published: November 2023

This study introduces a diffraction calculation that utilizes low-quantization input images and impulse responses. Quantization of signals enables more efficient calculations. The proposed method produces outcomes that are comparable to those achieved with floating-point formats.
Bilayer Berry Phase Metasurfaces with Linear Polarization Bases
Authors: Palmieri Alfonso , Dorrah Ahmed H. , Oh Jaewon , Dainese Paulo , Capasso Federico
Published: November 2023

We investigate the use of bilayer metasurfaces for arbitrary polarization transformations not achievable with single layer and we report on the first Berry phase metasurface which operates on linear (instead of circular) polarization bases.
Metalens-refractive hybrid eyepiece for reduced SWaP and expanded field of view near eye display
Authors: Kochan Nicholas S. , Simmons Evan L. , Rayno Michael R. , Woolf David N.
Published: November 2023

We present design process, evaluation, and prototype measurement of a 60
◦
full field of view hybrid metalens-refractive eyepiece for a near-eye display.
Multifunctional Spaceplates for Chromatic and Spherical Aberration Correction
Authors: Shao Yixuan , Lupoiu Robert , Jiang Jiaqi , Zhou You , Fan Jonathan A.
Published: November 2023

Multifunctional spaceplates are invented to simultaneously replace air gaps and reduce aberrations, which helps facilitate the miniaturization of imaging systems. We demonstrate designs of thin-film-multilayer spaceplates for chromatic and spherical aberration corrections.
Hardware-accelerated Full-wave Simulation of 3D Large Area Metalenses
Authors: Chen Xinzhong , Hughes Tyler W. , Minkov Momchil , Liu Victor , Yu Zongfu , Fan Shanhui
Published: November 2023

Advances in computing hardware have now created opportunities for full-wave simulation of large metalenses. We demonstrate that a hardware-accelerated FDTD solver is capable of simulating metalenses of diameter over 100 in full 3D.
Colored Structured Light Based on Nanoscale 3D Printing
Authors: Wang Hongtao , Wang Hao , Yang Joel K.W.
Published: November 2023

Through nanoscale two-photon polymerization (TPP) 3D printing, structured optical beams can be extended to colored structured light under incoherent white light illumination, promising higher-dimensional structured light and advanced optical authentication.
MOE-based dot and flood projector modules for 3D sensing applications
Authors: Hashemi Ehsan , Francois Olivier , Quaade Ulrich J.
Published: November 2023

Dot projector and flood illumination optics based on meta optical elements are demonstrated, showing high efficiency and uniformity as well as wide field of illumination and low zero-order performance suitable for 3D sensing.
Metalenses for imaging and sensing modules
Authors: Quaade Ulrich J. , Mattinson Frederik , Johansen Villads , Fly Jesper , Schmidlin Moritz
Published: November 2023

Single metalens imaging modules show a rigid design space with limited room for performance modification. Two surface metalens modules show a much richer design space enabling optimization to different performance variables for various applications.
Nonlinear residual error compensation of a robot vision system using a rotary laser scanner
Authors: Ye Fan , Wang Yukun , Chen Xiaobo , Xi Juntong
Published: November 2023

We design a rotary laser scanner integrated into an industrial robot. Then, the robot vision system is modeled and calibrated by scanning point cloud of spheres from different poses. A PR-DNN is presented to compensate nonlinear residual error and the RMSE can reach 0.0611mm.
Imaging of Microparticles Separated by the Coffee Ring Effect via Infrared Photothermal Spectroscopy
Authors: Su Yufeng , Hutter Tanya
Published: November 2023

The coffee ring effect was used to separate two types of microparticles - bacteria and polystyrene beads, and the partition was optically measured using imaging infrared photothermal spectroscopy.
Bioinspired UV-Visible Multispectral Imaging Sensor Enabled by Perovskite Nanocrystal Coating
Authors: Chen Cheng , Wang Ziwen , Wu Jiajing , Deng Zhengtao , Zhang Tao , Zhu Zhongming , Jin Yifei , Lew Benjamin , Srivastava Indrajit , Liang Zuodong , Nie Shuming , Gruev Viktor
Published: November 2023

Inspired by the visual system of Papilio xuthus butterfly, we fabricated a ultraviolet-visible multispectral imager which combines perovskite nanocrystals and vertically stacked silicon photodetectors. High-resolution ultraviolet imaging with both intensity and spectral information was achieved.
Anomaly Detection of Injection Molded Products Using Polarimetric Camera and AnoGAN
Authors: Nozawa Itta , Amada Masaki , Tsukahara Shinichiro
Published: November 2023

This paper reports on anomaly-detection method for injection molded products using polarimetric imaging and AnoGAN. As a result, we demonstrated the effectiveness of this method by verifying the AUC score was 0.94.
Biomedical imaging and sensing in the near-infrared using fluorescent single-walled carbon nanotubes
Authors: Bisker Gili
Published: November 2023

We present an overview of recent advancements in biomedical imaging and sensing using near-infrared fluorescent single-walled carbon nanotubes, providing real-time spatiotemporal information.
Single-Pixel Structured Illumination Microscopy
Authors: Ordóñez Luis , Lenz Armin J. M. , Lancis Jesús , Tajahuerce Enrique
Published: November 2023

We describe a single-pixel imaging microscope with super-resolution properties based on structured illumination microscopy. Spatially resolved patterns are used to expand the frequency spectrum of sampling patterns in the Fourier space.
Approach for estimating the vertical distribution of the diffuse attenuation coefficient in the South China Sea
Authors: Zhang Xianqing , Li Cai , Zheng Yuanning , Liu Cong , Zhou Wen , Xu Zhantang , Yang Zeming , Yang Yuezhong , Cao Wenxi
Published: November 2023

The vertical distribution of the diffuse attenuation coefficient K(z, λ) is critical for studies in bio-optics, ocean color remote sensing, underwater photovoltaic power, etc. It is a key apparent optical property (AOP) and is sensitive to the volume scattering function β(ψ, z, λ). Here, using three machine learning algorithms (MLAs) (categorical boosting (CatBoost), light gradient boosting machine (LightGBM), and random forest (RF)), we developed a new approach for estimating the vertical distribution of K
d
(z, 650), K
Lu
(z, 650), and K
u
(z, 650) and applied it to the South China Sea (SCS). In this approach, based on in situ β(ψ, z, 650), the absorption coefficient a(z, 650), the profile depths z, and K
d
(z, 650), K
Lu
(z, 650), and K
u
(z, 650) calculated by Hydrolight 6.0 (HL6.0), three machine learning models (MLMs) without or with boundary conditions for estimating K
d
(z, 650), K
Lu
(z, 650), and K
u
(z, 650) were established, evaluated, compared, and applied. It was found that (1) CatBoost models have superior performance with R 2 ≥ 0.92, RMSE≤ 0.021 m−1, and MAPE≤ 4.3% and most significantly agree with HL6.0 simulations; (2) there is a more satisfactory consistency between HL6.0 simulations and MLMs estimations while incorporating the boundary conditions; (3) the estimations of K
d
(z, 650), K
Lu
(z, 650), and K
u
(z, 650) derived from CatBoost models with and without boundary conditions have a good agreement with R 2 ≥0.992, RMSE ≤0.007 m−1, and MAPE≤0.8%, respectively; (4) there is an overall decreasing trend with increasing depth and increasing offshore distance of K
d
(z, 650), K
Lu
(z, 650), and K
u
(z, 650) in the SCS. The MLMs for estimating K(z, λ) could provide more accurate information for the study of underwater light field distribution, water quality assessment and the validation of remote sensing data products.
End-to-end compression-aware computer-generated holography
Authors: Zhou Mi , Zhang Hao , Jiao Shuming , Chakravarthula Praneeth , Geng Zihan
Published: November 2023

Joint photographic experts group (JPEG) compression standard is widely adopted for digital images. However, as JPEG encoding is not designed for holograms, applying it typically leads to severe distortions in holographic projections. In this work, we overcome this problem by taking into account the influence of JPEG compression on hologram generation in an end-to-end fashion. To this end, we introduce a novel approach to merge the process of hologram generation and JPEG compression with one differentiable model, enabling joint optimization via efficient first-order solvers. Our JPEG-aware end-to-end optimized holograms show significant improvements compared to conventional holograms compressed using JPEG standard both in simulation and on experimental display prototype. Specifically, the proposed algorithm shows improvements of 4 dB in peak signal-to-noise ratio (PSNR) and 0.27 in structural similarity (SSIM) metrics, under the same compression rate. When maintained with the same reconstruction quality, our method reduces the size of compressed holograms by about 35% compared to conventional JPEG-compressed holograms. Consistent with simulations, the experimental results further demonstrate that our method is robust to JPEG compression loss. Moreover, our method generates holograms compatible with the JPEG standard, making it friendly to a wide range of commercial software and edge devices.
High-speed parallel processing with photonic feedforward reservoir computing
Authors: Zhang Junfeng , Ma Bowen , Zou Weiwen
Published: November 2023

High-speed photonic reservoir computing (RC) has garnered significant interest in neuromorphic computing. However, existing reservoir layer (RL) architectures mostly rely on time-delayed feedback loops and use analog-to-digital converters for offline digital processing in the implementation of the readout layer, posing inherent limitations on their speed and capabilities. In this paper, we propose a non-feedback method that utilizes the pulse broadening effect induced by optical dispersion to implement a RL. By combining the multiplication of the modulator with the summation of the pulse temporal integration of the distributed feedback-laser diode, we successfully achieve the linear regression operation of the optoelectronic analog readout layer. Our proposed fully-analog feed-forward photonic RC (FF-PhRC) system is experimentally demonstrated to be effective in chaotic signal prediction, spoken digit recognition, and MNIST classification. Additionally, using wavelength-division multiplexing, our system manages to complete parallel tasks and improve processing capability up to 10 GHz per wavelength. The present work highlights the potential of FF-PhRC as a high-performance, high-speed computing tool for real-time neuromorphic computing.
Spin-orbit coupling induced polarization transform in the autofocusing of ring Airy beams with hybrid polarizations
Authors: Zhang Xiang , Han Lei , Wu Xuanguang , Du Jianying , Xin Yujie , Wei Bingyan , Liu Sheng , Li Peng , Zhao Jianlin
Published: November 2023

Manipulating polarization is of significance for the application of light. Spin-orbit coupling provides a prominent pathway for manipulating the polarization of light field but generally requires tight focusing conditions or anisotropic media. In this paper, we construct ring Airy beams with hybrid polarizations and reveal the controllable polarization transforms in their autofocusing dynamics by manipulating concomitant spin-orbit coupling in free space. The numerical and experimental results show that the polarization transform is dependent on the azimuthal orders of amplitude and vortex phases of two spin constituents of ring Airy beams, that the focal spots present pure linear polarization whose orientation is determined by the initial phase when the vortex phase topological charge is equal to the amplitude angular factor, otherwise, the focal fields present cylindrical vector polarizations whose orders depend on the difference of amplitude angular orders and topological charges. Our work provides new insights for studying spin-orbit interactions and the depolarization of complex polarization.
Iterative eigensolver using fixed-point photonic primitive
Authors: Klein Andrew B. , Zhu Zheyuan , Saiham Dewan , Li Guifang , Pang Shuo S.
Published: November 2023

Photonic computing has potential advantages in speed and energy
consumption yet is subject to inaccuracy due to the limited equivalent
bitwidth of the analog signal. In this Letter, we demonstrate a
configurable, fixed-point coherent photonic iterative solver for
numerical eigenvalue problems using shifted inverse iteration. The
photonic primitive can accommodate arbitrarily sized sparse
matrix–vector multiplication and is deployed to solve
eigenmodes in a photonic waveguide structure. The photonic iterative
eigensolver does not accumulate errors from each iteration, providing
a path toward implementing scientific computing applications on
photonic primitives.
Suppressing the dephasing of optically trapped atoms inside a hollow-core fiber
Authors: Song Yitong , Li Wei , Xu Xiaobin , Han Rui , Gao Chengchun , Dai Cheng , Song Ningfang
Published: November 2023

We demonstrate the suppression of inhomogeneous dephasing of cold 87Rb atoms optically trapped inside a hollow-core fiber. The differential light shift (DLS) for the clock transition caused by the trapping beam is reduced by one order of magnitude through the use of a weak compensation laser beam that is spatially mode-matched to the trapping beam. The coherence of the DLS-compensated system is characterized by microwave Ramsey interferometry, which shows Ramsey fringes with a contrast of over 0.6 at a separation time of 10 ms. The dephasing time, measured by Ramsey spectroscopy at different separation times, reaches tens of milliseconds after DLS cancellation, limited by the residual DLS caused by mode mismatching between the two laser beams. This work paves the way for compact and portable fiber-guided atom interferometers.
Monte Carlo simulation for KDP crystals induced by ultraviolet nanosecond laser irradiation
Authors: Zheng Runsheng , Sui Tingting , Zhuo Haohui , Ju Xin
Published: November 2023

Potassium dihydrogen phosphate and its deuteride (KDP/DKDP) are the only tripled frequency crystals used for inertial confinement fusion. The photonic behavior of KDP under laser irradiation is unknown. In this study, the ultraviolet photon transport behavior of KDP with different growth environments has been simulated based on the Monte Carlo method. By comparison, it is shown that the linear absorption of filtered grown crystal is obviously weaker, and the relaxation time is much longer. Moreover, the concentration of defects inside KDP is the critical cause of linear absorption and relaxation time. Finally, the influence of multi-photon absorption on the damage of KDP is discussed.
Low-repetition-rate optical frequency comb
Authors: Canella Francesco , Weitenberg Johannes , Thariq Muhammad , Schmid Fabian , Dwivedi Paras , Galzerano Gianluca , Hänsch Theodor W. , Udem Thomas , Ozawa Akira
Published: November 2023

Reducing the pulse repetition rate of an optical frequency comb increases the pulse energy for a given average power. This enhances the efficiency of nonlinear frequency conversion and it facilitates extending the accessible wavelength range, for example, into the extreme ultraviolet (XUV). The resulting spectrally dense frequency comb can still be used for precision spectroscopy of narrow atomic or molecular transitions. In this paper, we demonstrate a low-noise infrared frequency comb with a repetition rate as low as 40 kHz using a Yb:KYW mode-locked laser, pulse picking, and subsequent amplification. The frequency comb structure is confirmed by generating a beat note with a continuous wave reference laser. A comb mode is actively stabilized to the reference laser, and the integrated rms phase noise from 20 Hz to 20 kHz is measured to be 195 mrad.
Low-noise balanced homodyne detection with superconducting nanowire single-photon detectors
Authors: Protte Maximilian , Schapeler Timon , Sperling Jan , Bartley Tim J.
Published: November 2023

Superconducting nanowire single-photon detectors (SNSPDs) have been widely used to study the discrete nature of quantum states of light in the form of photon-counting experiments. We show that SNSPDs can also be used to study continuous variables of optical quantum states by performing homodyne detection at a bandwidth of 400 kHz. By measuring the interference of a continuous-wave field of a local oscillator with the field of the vacuum state using two SNSPDs, we show that the variance of the difference in count rates is linearly proportional to the photon flux of the local oscillator over almost five orders of magnitude. The resulting shot-noise clearance of (46.0 ± 1.1) dB is the highest reported clearance for a balanced optical homodyne detector, demonstrating their potential for measuring highly squeezed states in the continuous-wave regime. In addition, we measured a CMRR = 22.4 dB. From the joint click counting statistics, we also measure the phase-dependent quadrature of a weak coherent state to demonstrate our device’s functionality as a homodyne detector.
Scintillation Observed in an 84-km Propagation Experiment across White Sands Missile Range
Authors: Muschinski Andreas , Voelz David G. , Baca Andrea , Hull Robert
Published: November 2023

We present and discuss measurements collected during a long-range optical propagation experiment conducted in October, 2022 at the White Sands Missile Range, NM. The propagation path was 84 km long, and most of the path was between 600 m and 1500 m above ground level.
Historical Context and Origins of the Fried Parameter
Authors: Bos Jeremy P.
Published: November 2023

The Fried parameter is well known in the fields around atmospheric optics. Here, I provide historical context and highlight the common approaches used by Fried in approaching problems in atmospheric optics.
Scattering Media Interactions with Orbital Angular Momentum Laser Beams
Authors: Sivaprakasam Vasanthi
Published: November 2023

The angular elastic scattering signal intensity is calculated and measured from suspended single particles for laser beams that carry orbital angular momentum and is compared to that of a Gaussian beam.
Different pedagogical approaches to motor imagery both demonstrate individualized movement patterns to achieve improved performance outcomes when learning a complex motor skill
Authors: Lindsay Riki S. , Komar John , Chow Jia Yi , Larkin Paul , Spittle Michael
Published: November 2023

Cognitive training techniques such as motor imagery (MI)–cognitive simulation of movement, has been found to successfully facilitate skill acquisition. The MI literature emphasizes the need to accurately imitate key elements of motor execution to facilitate improved performance outcomes. However, there is a scarcity of MI research investigating how contemporary approaches to motor learning, such as nonlinear pedagogy (NLP), can be integrated into MI practice. Grounded in an ecological dynamics approach to human movement, NLP proposes that skilled action is an emergent process that results from continuous interactions between perceptual information of the environment and movement. This emergent process can be facilitated by the manipulation of key task constraints that aim to encourage learners to explore movement solutions that satisfy individual constraints (e.g., height and weight) and achieve successful performance outcomes. The aim of the present study was to explore the application of a NLP approach to MI approach for skill acquisition. Fourteen weightlifting beginners (two female and 12 male) participated in a 4-week intervention involving either NLP (i.e. analogy-based instructions and manipulation of task constraints) or a linear pedagogy (LP; prescriptive instructions of optimal technique, repetition of same movement form) to learn a complex weightlifting derivative. Performance accuracy, movement criterion (barbell trajectory type), kinematic data, and quantity of exploration/exploitation were measured pre-mid-post intervention. No significant differences (p = .438) were observed in the amount of exploration between LP (EER = 0.41) and NLP (EER = 0.26) conditions. Equivalent changes in rearward displacement (R×D) were observed with no significant differences between conditions for technique assessments 1, 2, or 3 (p = .13 - .67). Both NLP and LP conditions were found to primarily demonstrate ‘sub-optimal’ type 3 barbell trajectories (NLP = 72%; LP = 54%). These results suggest that MI instructions prescribing a specific movement form (i.e., LP condition) are ineffective in restricting available movements to a prescribed technique but rather the inherent task constraints appear to ‘force’ learners to explore alternative movement solutions to achieve successful performance outcomes. Although MI instructions prescribing specific techniques have previously supported improved skill development, the current findings indicate that learners may self-organise their movements regardless of MI instructions to satisfy individual and task constraints while achieving improved performance. Therefore, it may be beneficial to consider scripts that are more outcome focused and incorporate task constraints to facilitate learners’ inherent exploration of individual task solutions.
Classification of large ornithopod dinosaur footprints using Xception transfer learning
Authors: Ha Yeoncheol , Kim Seung-Sep
Published: November 2023

Large ornithopod dinosaur footprints have been confirmed on all continents except Antarctica since the 19th century. However, oversplitting problems in ichnotaxa have historically been observed in these footprints. To address these issues and distinguish between validated ichnotaxa, this study employed convolutional neural network-based Xception transfer learning to automatically classify ornithopod dinosaur tracks. The machine learning model was trained for 162 epochs (i.e., the number of full cycles of all training data through the model) using 274 data images, excluding horizontally flipped images. The trained model accuracy was 96.36%, and the validation accuracy was 92.59%. We demonstrate the performance of the machine learning model using footprint illustrations that are not included in the training dataset. These results show that the machine learning model developed in this study can properly classify footprint illustration data for large ornithopod dinosaurs. However, the quality of footprint illustration data (or images) inherently affects the performance of our machine learning model, which performs better on well-preserved footprints. In addition, because the developed machine-learning model is a typical supervised learning model, it is not possible to introduce a new label or class. Although this study used illustrations rather than photos or 3D data, it is the first application of machine-learning techniques at the academic level for verifying the ichnotaxonic assignments of large ornithopod dinosaur footprints. Furthermore, the machine learning model will likely aid researchers to classify the large ornithopod dinosaur footprint ichnotaxa, thereby safeguarding against the oversplitting problem.
Quantification of choroidal hyperreflective layer: A swept-source optical coherence tomography study
Authors: Ahn So Min , Song Myung-Sun , Togloom Ariunaa , Oh Jaeryung
Published: November 2023

Purpose

To investigate variation in reflectivity of choroidal layers in normal eyes.

Methods

From the swept-source optical coherence tomography database, we retrospectively included eyes with a normal fundus. Choroidal reflectivity was measured on the horizontal and vertical B-scan optical coherence tomography images. The optical barrier of the choroid was defined as the first hill in the middle of the reflectance graph from the retinal pigment epithelium-Bruch’s membrane complex to the chorioscleral junction.

Results

The optical barrier of the choroid was identified in 91 eyes of 91 individuals. The amplitude of peak reflectivity of the optical barrier of the choroid at macular center (142.85 ± 15.04) was greater than those in superior (136.12 ± 14.08) or inferior macula (135.30 ± 16.13) (P = 0.028, P = 0.008, respectively). Latency between the peak of the retinal pigment epithelium-Bruch’s membrane complex and the optical barrier of the choroid at macular center (48.11 ± 13.78 μm) was shorter than those in nasal macula (55.58 ± 19.21 μm) (P = 0.021). The amplitude of the peak reflectivity of the optical barrier of the choroid in the center negatively correlated with the latency between the retinal pigment epithelium-Bruch’s membrane complex and the optical barrier of the choroid (P < 0.001).

Conclusion

An optical barrier exists in the inner choroid of the normal eye. Its depth depends on the location within the macula. Further studies are mandatory to evaluate variations in the barrier in the eyes with chorioretinal disease.