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Adaptive optical focusing through perturbed scattering media with a dynamic mutation algorithm

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Photonics Research 2021年第2期9卷 202-212页

作者： HUANHAO LI chi man woo TIANTING ZHONG ZHIPENG YU YUNQI LUO YUANJIN ZHENG XIN YANG HUI HUI PUXIANG LAI Department of Biomedical Engineering The Hong Kong Polytechnic University The Hong Kong Polytechnic University Shenzhen Research Institute School of Electrical and Electronics Engineering Nanyang Technological University CAS Key Laboratory of Molecular Imaging Institute of AutomationChinese Academy of Sciences

Optical imaging through or inside scattering media, such as multimode fiber and biological tissues, has a significant impact in biomedicine yet is considered challenging due to the strong scattering nature of light. In the past decade, promising progress has been made in the field, largely benefiting from the invention of iterative optical wavefront shaping, with which deep-tissue high-resolution optical focusing and hence imaging becomes possible. Most of the reported iterative algorithms can overcome small perturbations on the noise level but fail to effectively adapt beyond the noise level, e.g., sudden strong perturbations. Reoptimizations are usually needed for significant decorrelation to the medium since these algorithms heavily rely on the optimization performance in the previous iterations. Such ineffectiveness is probably due to the absence of a metric that can gauge the deviation of the instant wavefront from the optimum compensation based on the concurrently measured optical *** this study, a square rule of binary-amplitude modulation, directly relating the measured focusing performance with the error in the optimized wavefront, is theoretically proved and experimentally validated. With this simple rule, it is feasible to quantify how many pixels on the spatial light modulator incorrectly modulate the wavefront for the instant status of the medium or the whole system. As an example of application, we propose a novel algorithm, the dynamic mutation algorithm, which has high adaptability against perturbations by probing how far the optimization has gone toward the theoretically optimal performance. The diminished focus of scattered light can be effectively recovered when perturbations to the medium cause a significant drop in the focusing performance, which no existing algorithms can achieve due to their inherent strong dependence on previous optimizations. With further improvement, the square rule and the new algorithm may boost or inspire many ap

关键词： scattering modulator algorithm

Long distance all-optical logic operations through a single multimode fiber empowered by wavefront shaping

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Photonics Research 2024年第3期12卷 587-597页

作者： ZHIPENG YU TIANTING ZHONG HUANHAO LI HAORAN LI chi man woo SHENGFU CHENG SHUMING JIAO HONGLIN LIU CHAO LU PUXIANG LAI Department of Biomedical Engineering The Hong Kong Polytechnic UniversityHong Kong SARChina Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518000China Peng Cheng Laboratory Shenzhen 518055China Key Laboratory for Quantum Optics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Department of Electronic and Information Engineering The Hong Kong Polytechnic UniversityHong Kong SARChina Photonics Research Institute The Hong Kong Polytechnic UniversityHong Kong SARChina

Multimode fibers(MMFs)are a promising solution for high-throughput signal transmission in the time ***,crosstalk among different optical modes within the MMF scrambles input information and creates seemingly random speckle patterns at the *** characterize this process,a transmission matrix(TM)can be used to relate input and output *** innovations use TMs to manipulate the output field by shaping the input wavefront for exciting advances in deep-brain imaging,neuron stimulation,quantum networks,and analog ***,these approaches consider input/output segments as independent,limiting their use for separate signal processing,such as logic *** proposed method,which makes input/output segments as interdependent,adjusts the phase of corresponding output fields using phase bias maps superimposed on input *** superposition enables signal logic operations through a 15-m-long *** experiments,a single optical logic gate containing three basic logic functions and cascading multiple logic gates to handle binary operands is *** operations are performed for multi-bit logic operations,and multiple optical logic gates are reconstructed simultaneously in a single logic gate with polarization *** proposed method may open new avenues for long-range logic signal processing and transmission via MMFs.

关键词： optical polarization fiber

Learning-based super-resolution interpolation for sub-Nyquist sampled laser speckles

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Photonics Research 2023年第4期11卷 631-642页

作者： HUANHAO LI ZHIPENG YU QI ZHAO YUNQI LUO SHENGFU CHENG TIANTING ZHONG chi man woo HONGLIN LIU LIHONG V.WANG YUANJIN ZHENG PUXIANG LAI Department of Biomedical Engineering Hong Kong Polytechnic UniversityHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518063China School of Electrical and Electronics Engineering Nanyang Technological UniversitySingapore 639798Singapore Key Laboratory for Quantum Optics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Caltech Optical Imaging Laboratory Andrew and Peggy Cherng Department of Medical EngineeringCalifornia Institute of TechnologyPasadenaCalifornia 91125USA Photonics Research Institute Hong Kong Polytechnic UniversityHong KongChina

Information retrieval from visually random optical speckle patterns is desired in many scenarios yet considered *** requires accurate understanding or mapping of the multiple scattering process,or reliable capability to reverse or compensate for the scattering-induced phase *** whatever situation,effective resolving and digitization of speckle patterns are ***,on some occasions,to increase the acquisition speed and/or signal-to-noise ratio(SNR),speckles captured by cameras are inevitably sampled in the sub-Nyquist domain via pixel binning(one camera pixel contains multiple speckle grains)due to finite size or limited bandwidth of *** a down-sampling process is irreversible;it undermines the fine structures of speckle grains and hence the encoded information,preventing successful information *** retrace the lost information,super-resolution interpolation for such sub-Nyquist sampled speckles is *** this work,a deep neural network,namely SpkSRNet,is proposed to effectively up sample speckles that are sampled below 1/10 of the Nyquist criterion to well-resolved ones that not only resemble the comprehensive morphology of original speckles(decompose multiple speckle grains from one camera pixel)but also recover the lost complex information(human face in this study)with high fidelity under normal-and low-light conditions,which is impossible with classic interpolation *** successful speckle super-resolution interpolation demonstrations are essentially enabled by the strong implicit correlation among speckle grains,which is non-quantifiable but could be discovered by the well-trained *** further engineering,the proposed learning platform may benefit many scenarios that are physically inaccessible,enabling fast acquisition of speckles with sufficient SNR and opening up new avenues for seeing big and seeing clearly simultaneously in complex scenarios.

关键词： speckle interpolation hence

Wavefront shaping: A versatile tool to conquer multiple scattering in multidisciplinary fields

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The Innovation 2022年第5期3卷 80-94页

作者： Zhipeng Yu Huanhao Li Tianting Zhong Jung-Hoon Park Shengfu Cheng chi man woo Qi Zhao Jing Yao Yingying Zhou Xiazi Huang Weiran Pang Hansol Yoon Yuecheng Shen Honglin Liu Yuanjin Zheng YongKeun Park Lihong V.Wang Puxiang Lai Department of Biomedical Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077China The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518052China Department of Biomedical Engineering Ulsan National Institute of Science and Technology(UNIST)Ulsan 44919Republic of Korea Tomocube Daejeon 34109Republic of Korea Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou 510275China Key Laboratory for Quantum Optics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China School of Electrical and Electronic Engineering Nanyang Technological University50 Nanyang Avenue201800 SingaporeSingapore Department of Physics Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea KAIST Institute for Health Science and Technology KAISTDaejeon 34141Republic of Korea Department of Medical Engineering California Institute of TechnologyPasadenaCA 91125USA Department of Electrical Engineering California Institute of TechnologyPasadenaCA 91125USA Photonics Research Institute The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077China

Optical techniques offer a wide variety of applications as light-matter interactions provide extremely sensitive mechanisms to probe or treat target *** of these implementations rely on the usage of ballistic or quasi-ballistic photons to achieve high spatial ***,the inherent scattering nature of light in biological tissues or tissue-like scattering media constitutes a critical obstacle that has restricted the penetration depth of non-scattered photons and hence limited the implementation of most optical techniques for wider *** addition,the components of an optical system are usually designed and manufactured for a fixed function or *** advances in wavefront shaping have demonstrated that scattering-or component-induced phase distortions can be compensated by optimizing the wavefront of the input light pattern through iteration or by conjugating the transmission matrix of the scattering medium.

关键词： versatile hence iteration

Calibration of the Solar X-ray Detector on-board the Macao Science Satellite-1B for Soft X-ray Detection

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Science china Earth Sciences 2025年第1期68卷 11-26页

作者： man-Hei NG Xiaoping ZHANG Jianwu CHEN Yongqiang SHI Fuchang ZUO Wenxi PENG Weichun FU Liansheng LI Pengwei LUO chi-Long TANG Guozheng ZHANG Zhiwu MEI Li WANG Cunhui LI Jiaming OU Yanyan XU State Key Laboratory of Lunar and Planetary Sciences Macau University of Science and Technology china National Space Administration (CNSA) Macau Center for Space Exploration and Science Space Optoelectronic Measurement and Perception Laboratory Beijing Institute of Control Engineering Institute of High Energy Physics Chinese Academy of Sciences Science and Technology on Vacuum Technology and Physics Laboratory Lanzhou Institute of Physics

The Solar X-ray Detector(SXD) on-board the Macao Science Satellite-1B(MSS-1B) was successfully launched via the chinese Long March-2C rocket on 21 May 2023, and commenced operations in early June of the same year. The MSS-1B/Soft X-ray Detection Units(SXDUs) employ two silicon drift detectors(SDDs), providing a wide range of energy spectra spanning from 0.7 to 24 keV. Notably, the SXDUs deliver a high-resolution capability of 0.14 keV@5.9 keV and operate with a time cadence of 1 second. Here, we perform thorough calibrations of the MSS-1B/SXDUs, employing a combination of ground experiments and simulations. In addition, quantitative analysis comparing the flux measurements obtained by the MSS-1B/SXDUs to the data collected by the Geostationary Operational Environmental Satellite(GOES), provides compelling evidence of their consistency. Furthermore, the preliminary spectral analysis results showcase the robustness and expected performance of the MSS-1B/SXDUs, unlocking their potential for facilitating the study of dynamic evolution of solar flares. Moreover, the innovative MSS-1B/Solar X-ray Detector facilitates concurrent observations of solar soft and hard X-rays, thereby making valuable contributions to the advancements in solar research.

关键词： Macao Science Satellite-1B (MSS-1B) Calibration Solar X-Ray Detector Spectrometer Soft X-rays Solar flares Solar abundances

The role of Epstein-Barr virus infection in the pathogenesis of nasopharyngeal carcinoma

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Virologica Sinica 2015年第2期30卷 107-121页

作者： chi man Tsang Sai Wah Tsao Department of Anatomy Li Ka Shing Faculty of Medicine University of Hong Kong Hong Kong SAR China

Nasopharyngeal carcinoma(NPC) is closely associated with Epstein-Barr virus(EBV) infection. EBV episomes are detected in almost all NPC cells. The role of EBV in NPC pathogenesis has long been postulated but remains enigmatic. In contrast to infection of B lymphocytes, EBV infection does not directly transform nasopharyngeal epithelial cells into proliferative clones with malignant potential. EBV infection of normal pharyngeal epithelial cells is predominantly lytic in nature. Genetic alterations in premalignant nasopharyngeal epithelium, in combination with inflammatory stimulation in the nasopharyngeal mucosa, presumably play essential roles in the establishment of a latent EBV infection in infected nasopharyngeal epithelial cells during the early development of NPC. Establishment of latent EBV infection in premalignant nasopharyngeal epithelial cells and expression of latent viral genes, including the BART transcripts and BART-encoded micro RNAs, are crucial features of NPC. Expression of EBV genes may drive further malignant transformation of premalignant nasopharyngeal epithelial cells into cancer cells. The difficulties involved in the establishment of NPC cell lines and the progressive loss of EBV epsiomes in NPC cells propagated in culture strongly implicate the contribution of host stromal components to the growth of NPC cells in vivo and maintenance of EBV in infected NPC cells. Defining the growth advantages of EBV-infected NPC cells in vivo will lead to a better understanding of the contribution of EBV infection in NPC pathogenesis, and may lead to the identification of novel therapeutic targets for NPC treatment.

关键词： Epstein-Barr virus(EBV) nasopharyngeal carcinoma latent infection pathogenesis inflammation

Interplay of laser power and pore characteristics in selective laser melting of ZK60 magnesium alloys:A study based on in-situ monitoring and image analysis

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Journal of Magnesium and Alloys 2024年第4期12卷 1346-1366页

作者： Weijie Xie Hau-Chung man chi-Wai Chan Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHong KongChina School of Mechanical and Aerospace Engineering Queen’s UniversityBelfast BT95AHUK Research Institute for Advanced manufacturing The Hong Kong Polytechnic UniversityHong KongChina

This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)***-speed in-situ monitoring was employed to visualise process signals in real-time,elucidating the dynamics of melt pools and vapour plumes under varying laser power conditions specifically between 40 W and 60 *** morphological analysis was performed using Scanning-Electron Microscopy(SEM),demonstrating a critical correlation between laser power and pore *** laser power led to increased pore coverage,whereas a denser structure was observed at higher laser *** laser power influence on porosity was further confirmed via Optical Microscopy(OM)conducted on both top and cross-sectional surfaces of the *** increase in laser power resulted in a decrease in pore coverage and pore size,potentially leading to a denser printed part of Mg alloy.X-ray Computed Tomography(XCT)augmented these findings by providing a 3D volumetric representation of the sample internal structure,revealing an inverse relationship between laser power and overall pore *** laser power appeared to favour the formation of interconnected pores,while a reduction in interconnected pores and an increase in isolated pores were observed at higher *** interplay between melt pool size,vapour plume effects,and laser power was found to significantly influence the resulting porosity,indicating a need for effective management of these factors to optimise the SLM process of Mg alloys.

关键词： Selective laser melting(SLM) Magnesium(Mg)alloys Biodegradable implants Porosity In-situ monitoring

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深层生物组织光学技术发展及其应用(特邀)

中国激光 2024年第1期51卷 330-353页

作者：赖溥祥赵麒周颖颖程圣福胡子敏李焕浩余志鹏黄夏子姚靖庞未然李浩然黄浩梵李文钊郑源东王志远袁楚琪仲天庭香港理工大学生物医学工程系中国香港九龙999077 香港理工大学深圳研究院广东深圳518055 香港理工大学光子技术研究院中国香港九龙999077 香港理工大学体育科技研究院中国香港九龙999077

光学技术在生物医学中扮演着越来越重要的角色,其非电离辐射、高分辨率、高对比度和对生物组织异变高度灵敏等特性使其非常适用于生物组织的研究,包括成像、传感、治疗、刺激以及控制等。然而由于光折射因子在生物组织中的分布是不均匀... 详细信息

光学技术在生物医学中扮演着越来越重要的角色,其非电离辐射、高分辨率、高对比度和对生物组织异变高度灵敏等特性使其非常适用于生物组织的研究,包括成像、传感、治疗、刺激以及控制等。然而由于光折射因子在生物组织中的分布是不均匀的,光在生物组织中的传播会受到很强的散射影响,故纯光学技术的穿透深度和空间分辨率是“鱼和熊掌不可兼得”;高分辨率光学成像应用仅限于样品浅表层,当成像深度增加时分辨率急剧下降。实现光在深层生物组织里的高分辨率成像或应用是人们期盼已久的目标。近年来,为解决这一问题,研究者提出了不同的方法,例如切换到更长的光波长以减小组织散射系数,在信号检测时将漫射光转换为散射不明显的超声信号,逆转或者预先补偿由光的多次散射所带来的相位畸变,或借助光纤等微创光学通道实现深层生物组织的高分辨率光学成像、刺激等。基于团队在深层生物组织光学相关领域多年的耕耘,从光在生物组织中的传播特性出发,梳理和总结了近年来研究人员在光-声结合和光学波前整形技术等方面展开的诸多探索,以及在生物组织操控、成像、光学计算以及人工智能等领域中的应用尝试。虽然尚有诸多不足,但随着硬件设备的更新和计算技术的发展,在不远的将来有望实现活体深层生物组织光学高分辨率应用。在这一求索过程中,新方法和新能力将不断激发新的应用灵感,为光学尤其是生物医学光子学带来全新的理念和机遇。

关键词：生物光学光学成像生物医学光子学深层组织光学波前整形光声成像

Activity origin and design principles for atomic vanadium anchoring on phosphorene monolayer for nitrogen reduction reaction

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Nano Research 2020年第11期13卷 2925-2932页

作者： Xiongyi Liang Xiangxuan Deng Chen Guo chi-man Lawrence Wu Department of Materials Science and Engineering City University of Hong KongHong KongChina

Conversion of inert N2 molecules into NH3 via electrochemical methods is an environmentally friendly alternative to replace the traditional Haber-Bosch ***,the development of highly efficient catalyst is still ***,we report a density functional theory(DFT)based high-throughput screening to investigate the potential of 23 atomic transition metals(Sc,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Y,Zr,Nb,Mo,Tc,Ru,Rh,Pd,Ag,Cd,W,Pt and Au)supported on phosphorene monolayer as electrocatalyst for nitrogen reduction reaction(NRR).Our theoretical results demonstrate that V single atom anchoring on phosphorene monolayer exhibits good thermal stability,selectivity and excellent catalytic activity with a low overpotential of 0.18 ***,rational design principles and electronic descriptor between the intrinsic electronic properties and activation barrier have been *** work offers a new promising noble metal-free catalyst for NRR and reveals profound insights into the activity origin to guide further design.

关键词： high-throughput screening density functional theory phosphorene electronic descriptor single atomic catalyst transition metal