期刊文献+
任意字段
题名或关键词
题名
关键词
摘要
作者
第一作者
机构
刊名
分类号
参考文献
作者简介
基金资助
栏目信息
共找到1,867篇文章
< 1 2 … 94 >
每页显示 20 50 100
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
显示方式：
Compact Fundus Imaging System Using Shack-Hartmann Wavefront Sensing for High-speed Auto-focus 认领 引用
1
作者 LIN Zhe-Kai CHEN Long +7 位作者 ZHENG Geng-Yong HUANG Jin-Tian DONG Jia-Xin YANG Shang-Pan DING Wen-Zheng HAN Ding-An WANG Xue-Hua ZENG Ya-Guang 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2026年第4期1076-1086,共11页
Objective The widespread adoption of portable fundus cameras for primary care and community screening is hindered by limitations in current autofocus(AF)technologies.Image-based methods relying on sharpness evaluation... Objective The widespread adoption of portable fundus cameras for primary care and community screening is hindered by limitations in current autofocus(AF)technologies.Image-based methods relying on sharpness evaluation require iterative searches,resulting in slow convergence,while projection-based techniques are susceptible to optical artifacts and calibration errors.To address these challenges,this study introduces a novel AF system based on direct wavefront sensing,designed to deliver simultaneous high speed,high precision,and operational robustness within the compact form factor essential for portable ophthalmic devices.Methods Our approach fundamentally reimagines the AF process by directly measuring the ocular wavefront aberration.We developed a custom portable fundus camera integrating a miniaturized Shack-Hartmann wavefront sensor(SHWS)into the optical path.An 850 nm laser diode projects a point source onto the retina via oblique illumination to minimize corneal reflections.Light scattered from this spot carries the eye’s refractive error through the imaging optics and is directed to the SHWS,positioned at a plane optically conjugate to the primary color CMOS imaging sensor.A microlens array within the SHWS samples the incident wavefront,generating a pattern of focal spots on a CCD.Real-time centroid analysis of these spots provides a map of local wavefront slopes.These measurements are processed through a singular value decomposition(SVD)algorithm to fit a Zernike polynomial basis set,enabling real-time reconstruction of the wavefront phase.The defocus component(S)is extracted from the second-order Zernike coefficients,providing a direct,quantitative measure of the refractive error in diopters.This value serves as a precise error signal in a closed-loop control system,which commands a voice-coil actuated focusing lens to its null position in a single,deterministic step,eliminating the need for iterative search algorithms.Results Comprehensive evaluation demonstrated the system’s high performance.Testing on a calibrated model eye(OEMI-7)established a highly linear relationship between the computed defocus S and the focusing lens position across a±20 Diopter(D)compensation range,achievable within a 5 mm mechanical travel.The system achieved a focusing precision of 0.08 D,corresponding to an 18-fold improvement over a conventional projection spot-size method tested under identical conditions.The total focus acquisition time,encompassing wavefront measurement,computation,and lens actuation,averaged under 0.5 s.Clinical validation with 25 human volunteers(50 eyes,refractive range-15 D to+10 D)confirmed practical efficacy.The wavefront-sensing AF succeeded in 92%of attempts with a mean time of 0.5 s,substantially outperforming a projection-based benchmark which achieved only a 32%success rate with an average time of 4.25 s.The system provided instantaneous directional guidance and maintained stability during minor ocular movements.Objective assessment of image quality,via amplitude contrast of retinal vasculature,showed consistent and significant enhancement following AF correction across the entire tested diopter range.Conclusion This work successfully implements and validates a direct wavefront-sensing autofocus paradigm for portable fundus cameras.By directly quantifying and compensating for the optical defocus aberration,this method bypasses the fundamental limitations of image-processing and projection-based techniques,enabling rapid,precise,and deterministic diopter compensation.The developed system delivers an exceptional combination of a wide operational range(±20 D),high accuracy(0.08 D),fast convergence(0.5 s),and a compact physical footprint.This technology provides a practical and highperformance focusing solution capable of enhancing the reliability,throughput,and diagnostic utility of portable retinal imaging in large-scale screening applications.Future efforts will be directed towards system cost optimization and performance adaptation for diverse ocular conditions. 展开更多
关键词 portable fundus camera autofocus wavefront detection Shack-Hartmann wavefront sensor
暂未订购 下载PDF
Single-shot wavefront sensing enabled by a photonic integrated circuit 认领 引用
2
作者 Wenyu Chen Zixin Zhao +3 位作者 Shiyuan Liu Hui Deng Liang Gao Jinlong Zhu 《Advanced Photonics Nexus》 CSCD 2026年第1期131-139,共9页
Point-of-care diagnostics and inline quantitative phase imaging(QPI)drive the demand for portable,ultra-miniaturized,and robust optical imaging and metrology systems.We propose and demonstrate a wavefront sensor integ... Point-of-care diagnostics and inline quantitative phase imaging(QPI)drive the demand for portable,ultra-miniaturized,and robust optical imaging and metrology systems.We propose and demonstrate a wavefront sensor integrated into a photonic integrated circuit,enabling single-shot optical phase retrieval.We implemented an integrated wavefront sensor array with a spatial resolution of 17μm and a numerical aperture of 0.1.Furthermore,we experimentally demonstrated the reconstruction of wavefronts defined by Zernike polynomials,specifically the first 14 terms(Z1to Z14),achieving an average root mean square error below 0.07.This advancement paves the way for fully integrated,portable,and robust optical imaging systems,facilitating integrated wavefront sensors in demanding applications such as point-of-care diagnostics,endoscopy,in situ QPI,and inline surface profile measurement. 展开更多
关键词 wavefront sensing photonic integrated circuit computational imaging miniaturized optical system
暂未订购 下载PDF
Pixelated liquid crystal programmable metasurface enabled multi-functional terahertz near-field wavefront manipulation 认领 引用
3
作者 YUAN FU XIAOJIAN FU +4 位作者 LIFENG CHEN PENG WANG LIHAO HUANG JUN YANG TIE JUN CUI 《Photonics Research》 SCIE EI CAS CSCD 2026年第5期2068-2079,共12页
Reconfigurable intelligent surface(RIS)technology is believed to effectively solve the dilemma of terahertz wireless communication in non-line-of-sight scenarios.Notably,the deployment of large-scale RIS arrays at hig... Reconfigurable intelligent surface(RIS)technology is believed to effectively solve the dilemma of terahertz wireless communication in non-line-of-sight scenarios.Notably,the deployment of large-scale RIS arrays at high frequencies brings about significant near-field effects,resulting in extensive near-field areas,which provides the possibility for the application of near-field communication.In this paper,a pixelated liquid crystal program-mable metasurface(PLCPM)is proposed to effectively manipulate terahertz waves in the near-field region.Leveraging the tunability of liquid crystal(LC)materials,the proposed PLCPM achieves 1-bit phase coding capability within the 104-110 GHz frequency band. 展开更多
关键词 multi functional terahertz near field wavefront manipulation manipulate terahertz terahertz wireless communication reconfigurable intelligent surface pixelated liquid crystal programmable metasurface non line sight scenarios near field communication reconfigurable intelligent surface ris technology
暂未订购 下载PDF
Acoustic Reconfigurable Metagratings with High Quality Factor for Anomalous Wavefront Control 认领 引用
4
作者 Fu Xu MengRu Jiang +3 位作者 Yu Chen Junyi Yang Zhanlei Hao Yadong Xu 《Chinese Physics Letters》 SCIE EI CAS CSCD 2026年第6期172-176,共5页
Acoustic resonance metasurfaces have emerged as versatile platforms for the precise manipulation of acoustic waves,yet existing designs suffer from fundamental trade-offs among reconfigurability,structural complexity,... Acoustic resonance metasurfaces have emerged as versatile platforms for the precise manipulation of acoustic waves,yet existing designs suffer from fundamental trade-offs among reconfigurability,structural complexity,and resonance quality factors(Q).Here,we theoretically propose and experimentally demonstrate a structural design of acoustic reconfigurable metagratings(ARMs)that achieves a high-Q Fano resonance via transverse translation of a tunable baffle.This mechanism is enabled by dynamic coupling between discrete local dark modes(first-order guided modes)and continuous bright modes(fundamental guided modes)confined within grooves,creating a pronounced Fano resonance.In contrast to traditional static metagratings,this device enables reversible switching between the state of perfect specular reflection and anomalous reflection using only a subwavelength displacement of the tunable baffle.Furthermore,we analytically elucidate the mechanism of Fano resonance in ARMs and derive the expression for the resonance condition.All theoretical predictions are rigorously validated through full-wave simulations and experimental measurements.This work establishes a paradigm for designing high-Q acoustic components with tunable functionality,opening new avenues for applications in ultrasonic sensing and information processing. 展开更多
关键词 high quality factor acoustic metagratings acoustic reconfigurable metagratings arms anomalous wavefront control acoustic resonance metasurfaces transverse translation tunable bafflethis acoustic resonance
暂未订购 下载PDF
Design of a compact wide-field-of-view infrared imager based on wavefront coding 认领 引用
5
作者 Chonghui Zhu Jiaqian Yu Jingang Cui 《Chinese Physics B》 SCIE EI CAS CSCD 2026年第2期383-388,共6页
Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution... Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution and wide FOV,infrared optical systems often adopt complex optical lens groups,which will increase the size and weight of the optical system.In this paper,a strategy based on wavefront coding(WFC)is proposed to design a compact wide-FOV infrared imager.A cubic phase mask is inserted into the pupil plane of the infrared imager to correct the aberration.The simulated results show that,the WFC infrared imager has good imaging quality in a wide FOV of±16°.In addition,the WFC infrared imager achieves compactness with its 40 mm×40 mm×40 mm size.A fast focal ratio of 1 combined with an entrance pupil diameter of 25 mm ensures brightness.This work is of significance for designing a compact wide-FOV infrared imager. 展开更多
关键词 optical design infrared imager wavefront coding
暂未订购 下载PDF
Near-field differential scattering algorithm for wavefront control in precise microsphereassisted laser nanofabrication 认领 引用
6
作者 Wei Liang Chen Zhao +2 位作者 Zhiwen Gao Zhiyang Xu Yinzhou Yan 《Advanced Photonics Nexus》 CSCD 2026年第4期136-146,共11页
Microsphere arrays exhibit significant potential in large-area laser processing due to their high numerical aperture for near-field nanofocusing and self-assembly properties for scalable deployment.However,the complex... Microsphere arrays exhibit significant potential in large-area laser processing due to their high numerical aperture for near-field nanofocusing and self-assembly properties for scalable deployment.However,the complexity of wavefront-modulated light interaction with microspheres presents significant challenges in predicting and optimizing processing outcomes.Therefore,developing accurate computational models to elucidate and tailor these near-field effects is essential to translate the inherent advantages of microspheres into reliable and efficient nanofabrication processes.This work presents a near-field differential scattering(NFDS)algorithm for high-fidelity and computationally efficient calculation of microsphere-assisted near-field nanofocusing.The algorithm advances conventional Mie scattering theory by incorporating wavefront characteristics and localized near-field corrections.Through comparison with experimental results,the in-plane polarization component is identified as the critical factor determining processing outcomes.Furthermore,the NFDS framework is integrated into a corrective patterning workflow for microsphere arrays,demonstrating its capability to achieve precise positional alignment and tailored morphological control in the fabrication of functional micro-and nanostructures.This work bridges the gap between high-accuracy physical modeling and practical nanofabrication,establishing a scalable computational foundation for wavefrontengineered microsphere photolithography. 展开更多
关键词 microsphere array Mie scattering theory laser processing wavefront control polarization
暂未订购 下载PDF
A differential Lucy-Richardson-Rosen Algorithm for near-diffractionlimited image restoration guided by wavefront sensing 认领 引用
7
作者 Lianhui Zheng Zhongjian Gao 《Astronomical Techniques and Instruments》 CSCD 2026年第3期250-259,共10页
The Lucy-Richardson-Rosen Algorithm is widely used for image restoration,but suffers from slow convergence or failure when analyzing images with severe optical aberrations and high noise.To address these limitations,w... The Lucy-Richardson-Rosen Algorithm is widely used for image restoration,but suffers from slow convergence or failure when analyzing images with severe optical aberrations and high noise.To address these limitations,we propose the Differential Lucy-Richardson-Rosen Algorithm which enhances both robustness and convergence speed.By integrating a Hartmann-Shack wavefront sensor into the imaging system,our proposed algorithm directly measures wavefront distortions to accurately estimate the spatially varying point spread function,enabling high-fidelity non-blind deconvolution,even for images acquired by ground-based telescopes,with significant optical imperfections.Extensive simulations and experiments demonstrate that our proposed algorithm outperforms its predecessor in image quality and computational efficiency under challenging aberration and noise conditions.Its rapid and stable performance makes it particularly suitable for real-time or near-real-time astronomical imaging,where reliable,high-resolution recovery is critical.This work advances computational imaging for next-generation astronomical instrumentation through a tightly coupled hardware-algorithm framework. 展开更多
关键词 Image restoration Lucy-Richardson-Rosen Algorithm Wavefront sensing Point Spread Function estimation Astronomical instrumentation
暂未订购 下载PDF
Real-Time Programmable Nonlinear Wavefront Shaping with Si Metasurface Driven by Genetic Algorithm 认领 引用 被引量：1
8
作者 Ze Zheng Gabriel Sanderson +4 位作者 Soheil Sotoodeh Chris Clifton Cuifeng Ying Mohsen Rahmani Lei Xu 《Engineering》 SCIE EI CSCD 2025年第6期90-95,共6页
Nonlinear wavefront shaping is crucial for advancing optical technologies,enabling applications in optical computation,information processing,and imaging.However,a significant challenge is that once a metasurface is f... Nonlinear wavefront shaping is crucial for advancing optical technologies,enabling applications in optical computation,information processing,and imaging.However,a significant challenge is that once a metasurface is fabricated,the nonlinear wavefront it generates is fixed,offering little flexibility.This limitation often necessitates the fabrication of different metasurfaces for different wavefronts,which is both time-consuming and inefficient.To address this,we combine evolutionary algorithms with spatial light modulators(SLMs)to dynamically control wavefronts using a single metasurface,reducing the need for multiple fabrications and enabling the generation of arbitrary nonlinear wavefront patterns without requiring complicated optical alignment.We demonstrate this approach by introducing a genetic algorithm(GA)to manipulate visible wavefronts converted from near-infrared light via third-harmonic generation(THG)in a silicon metasurface.The Si metasurface supports multipolar Mie resonances that strongly enhance light-matter interactions,thereby significantly boosting THG emission at resonant positions.Additionally,the cubic relationship between THG emission and the infrared input reduces noise in the diffractive patterns produced by the SLM.This allows for precise experimental engineering of the nonlinear emission patterns with fewer alignment constraints.Our approach paves the way for self-optimized nonlinear wavefront shaping,advancing optical computation and information processing techniques. 展开更多
关键词 Nonlinear metasurface Genetic algorithm Wavefront manipulation
暂未订购 下载PDF
Comparison between iterative wavefront control algorithm and direct gradient wavefront control algorithm for adaptive optics system 认领 引用 被引量：3
9
作者 程生毅 刘文劲 +3 位作者 陈善球 董理治 杨平 许冰 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第8期391-397,共7页
Among all kinds of wavefront control algorithms in adaptive optics systems, the direct gradient wavefront control algorithm is the most widespread and common method. This control algorithm obtains the actuator voltage... Among all kinds of wavefront control algorithms in adaptive optics systems, the direct gradient wavefront control algorithm is the most widespread and common method. This control algorithm obtains the actuator voltages directly from wavefront slopes through pre-measuring the relational matrix between deformable mirror actuators and Hartmann wavefront sensor with perfect real-time characteristic and stability. However, with increasing the number of sub-apertures in wavefront sensor and deformable mirror actuators of adaptive optics systems, the matrix operation in direct gradient algorithm takes too much time, which becomes a major factor influencing control effect of adaptive optics systems. In this paper we apply an iterative wavefront control algorithm to high-resolution adaptive optics systems, in which the voltages of each actuator are obtained through iteration arithmetic, which gains great advantage in calculation and storage. For AO system with thousands of actuators, the computational complexity estimate is about O(n2) ～ O(n3) in direct gradient wavefront control algorithm, while the computational complexity estimate in iterative wavefront control algorithm is about O(n) ～(O(n)3/2), in which n is the number of actuators of AO system. And the more the numbers of sub-apertures and deformable mirror actuators, the more significant advantage the iterative wavefront control algorithm exhibits. 展开更多
关键词 adaptive optics iterative wavefront control algorithm direct gradient wavefront control algorithm
暂未订购 下载PDF
Fast optical wavefront engineering for controlling light propagation in dynamic turbid media 认领 引用
10
作者 Meiyun Xia Deyu Li +1 位作者 Ling Wang Daifa Wang 《Journal of Innovative Optical Health Sciences》 SCIE EI 2019年第4期46-66,共21页
While propagating inside the strongly scattering biological tssue,photons lose their incident directions beyond one transport mean free path(TMFP,~1 millimeter(mm)),which makes it challenging to achieve optical focusi... While propagating inside the strongly scattering biological tssue,photons lose their incident directions beyond one transport mean free path(TMFP,~1 millimeter(mm)),which makes it challenging to achieve optical focusing or clear imaging deep inside tissue.By manipulating many degrees of the incident optical wavefront,the latest optical wavefront engineering(WFE)technology compensates the wavelfront distortions caused by the scattering media and thus is toward breaking this physical limit,bringing bright perspective to many applications deep inside tissue,eg,high resolution functional/molecular imaging,optical excitation(optogenetics)and optical tweezers.However,inside the dynamic turbid media such as the biological tissue,the wavefront distortion is a fast and continuously changing process whose decorrelation rate is on timescales from milliseconds(ms)to microseconds(μs),or even faster.This requires that the WFE technology should be capable of beating this rapid process.In this review,we discuss the major challenges faced by the WFE technology due to the fast decorrelation of dynamic turbid media such as living tissue when achieving light focusing/imaging and summarize the research progress achieved to date to overcome these challenges. 展开更多
关键词 Fast wavefront engineering optical phase conjugation feedback-based iterative wavefront optimization transmission matrix decorrelation time
暂未订购 下载PDF
Statistical virtual eye model based on wavefront aberration 认领 引用 被引量：2
11
作者 Jie-Mei Wang Chun-Ling Liu +2 位作者 Yi-Ning Luo Yi-Guang Liu Bing-Jie Hu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2012年第5期620-624,共5页
Wavefront aberration affects the quality of retinal image directly.This paper reviews the representation and reconstruction of wavefront aberration,as well as the construction of virtual eye model based on Zernike pol... Wavefront aberration affects the quality of retinal image directly.This paper reviews the representation and reconstruction of wavefront aberration,as well as the construction of virtual eye model based on Zernike polynomial coefficients.In addition,the promising prospect of virtual eye model is emphasized. 展开更多
关键词 wavefront aberration wavefront reconstruction virtual eye Zernike polynomial
暂未订购 下载PDF
A modified phase diversity wavefront sensor with a diffraction grating 认领 引用 被引量：14
12
作者 罗群 黄林海 +1 位作者 顾乃庭 饶长辉 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第9期251-258,共8页
The phase diversity wavefront sensor is one of the tools used to estimate wavefront aberration, and it is often used as a wavefront sensor in adaptive optics systems. However, the performance of the traditional phase ... The phase diversity wavefront sensor is one of the tools used to estimate wavefront aberration, and it is often used as a wavefront sensor in adaptive optics systems. However, the performance of the traditional phase diversity wavefront sensor is limited by the accuracy and dynamic ranges of the intensity distribution at the focus and defocus positions of the CCD camera. In this paper, a modified phase diversity wavefront sensor based on a diffraction grating is proposed to improve the ability to measure the wavefront aberration with larger amplitude and higher spatial frequency. The basic principle and the optics construction of the proposed method are also described in detail. The noise propagation property of the proposed method is also analysed by using the numerical simulation method, and comparison between the diffraction grating phase diversity wavefront sensor and the traditional phase diversity wavefront sensor is also made. The simulation results show that the diffraction grating phase diversity wavefront sensor can obviously improve the ability to measure the wavefront aberration, especially the wavefront aberration with larger amplitude and higher spatial frequency. 展开更多
关键词 phase diversity wavefront sensor diffraction grating aberration signal-to-noise ratio
暂未订购 下载PDF
Evaluations of wavefront aberrations and corneal surface regularity in dry eye patients measured with OPD Scan Ⅲ 认领 引用 被引量：10
13
作者 Rong-Jun Liu Bai-Kai Ma +2 位作者 Yu-Fei Gao Yi-Yun Liu Hong Qi 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2022年第3期407-412,共6页
AIM: To compare the wavefront aberrations and corneal surface regularity between dry eye(DE) patients and normal subjects and assess its diagnostic performance for DE measured with OPD Scan-Ⅲ.METHODS: Fifty right eye... AIM: To compare the wavefront aberrations and corneal surface regularity between dry eye(DE) patients and normal subjects and assess its diagnostic performance for DE measured with OPD Scan-Ⅲ.METHODS: Fifty right eyes of 50 DE patients and 31 right eyes of normal subjects were included.The examinations for ocular surface including logarithm of the minimum angle of resolution best-corrected distance visual acuity(logMAR BCVA) the ocular surface disease index(OSDI), tear film break-up time(TBUT) and corneal fluorescein staining(CFS).OPD Scan-Ⅲ was used to measure anterior corneal aberrations including total corneal aberrations, high order aberration(HOA), coma, trefoil, spherical aberration(SA), standard deviation of corneal power(SDP), surface regularity index(SRI) and surface asymmetry index(SAI).Statistical analysis were assessed with nonparametric tests and Spearman’s correlations.All parameters were also analyzed for sensitivity, specificity, and receiver operating characteristics(ROC) curves.RESULTS: Wavefront aberrations parameters including total corneal aberrations, HOA, coma, trefoil, and SA in DE group were significantly higher than those in normal group(P<0.001).Corneal surface regularity parameters including SRI and SAI in DE group were significantly higher than both in normal group(P<0.05).All the wavefront aberrations parameters had significant correlations with ocular surface parameters(P<0.05).The logMAR BCVA had positive correlations with SAI and SRI(all P<0.001).CFS scores had positive correlations with SAI and SRI(all P<0.001).All the wavefront aberrations parameters showed good diagnosis sensitivity and specificity, however, the corneal regularity parameters showed only good specificity but poor sensitivity.The cut-off value selected for trefoil in diagnosis DE showed the highest area under the curve(AUC, 0.921) values as compared to the other parameters with sensitivity of 0.955 and specificity of 0.867.CONCLUSION: Wavefront aberrations and corneal surface regularity are increased in DE patients and also correlated with ocular surface parameters.Wavefront aberrations parameters have potential to be indicators to diagnosis and monitor DE. 展开更多
关键词 dry eye wavefront aberration corneal surface regularity OPD ScanⅢ
暂未订购 下载PDF
Joint 3D traveltime calculation based on fast marching method and wavefront construction 认领 引用 被引量：6
14
作者 孙辉 孙建国 +5 位作者 孙章庆 韩复兴 刘明忱 刘志强 高正辉 石秀林 《Applied Geophysics》 SCIE CSCD 2017年第1期56-63,189,共8页
3D traveltime calculation is widely used in seismic exploration technologies such as seismic migration and tomography. The fast marching method （FMM） is useful for calculating 3D traveltime and has proven to be effi... 3D traveltime calculation is widely used in seismic exploration technologies such as seismic migration and tomography. The fast marching method （FMM） is useful for calculating 3D traveltime and has proven to be efficient and stable. However, it has low calculation accuracy near the source, which thus gives it low overall accuracy. This paper proposes a joint traveltime calculation method to solve this problem. The method firstly employs the wavefront construction method （WFC）, which has a higher calculation accuracy than FMM in calculating traveltime in the small area near the source, and secondly adopts FMM to calculate traveltime for the remaining grid nodes. Due to the increase in calculation precision of grid nodes near the source, this new algorithm is shown to have good calculation precision while maintaining the high calculation efficiency of FMM, which is employed in most of the computational area. Results are verified using various numerical models. 展开更多
关键词 Seismic wave propagation 3D traveltime computation fast marching method wavefront construction method
暂未订购 下载PDF
Active wavefront shaping for controlling and improving multimode fi ber sensor 认领 引用 被引量：4
15
作者 Tianting Zhong Zhipeng Yu +3 位作者 Huanhao Li Zihao Li Haohong Li Puxiang Lai 《Journal of Innovative Optical Health Sciences》 SCIE EI 2019年第4期127-135,共9页
Wavefront shaping(WFS)techniques have been used as a powerful tool to control light propagation in complex media,including multimode fibers.In this paper,we propose a new application of WFS for multimode fber-based se... Wavefront shaping(WFS)techniques have been used as a powerful tool to control light propagation in complex media,including multimode fibers.In this paper,we propose a new application of WFS for multimode fber-based sensors.The use of a single multimode fiber alone,without any special fabrication,as a sensor based on the light intensity variations is not an easy task.The twist effect on multimode fiber is used as an example herein.Experimental results show that light intensity through the multimode fiber shows no direct relationship with the twist angle,but the correlation coefficient(CC)of speckle patterns does.Moreover,if WFS is applied to transform the spatially seemingly random light pattern at the exit of the multimode fiber into an optical focus.The focal pattern correlation and intensity both can serve to gauge the twist angle,with doubled measurement range and allowance of using a fast point detector to provide the feedback.With further development,WFS may find potentials to facilitate the development of multimode fber-based sensors in a variety of scenarios. 展开更多
关键词 Multimode fiber wavefront shaping scattering media fiber sensor optical focusing
暂未订购 下载PDF
A thorough study on genetic algorithms in feedback-based wavefront shaping 认领 引用 被引量：6
16
作者 Daixuan Wu Jiawei Luo +1 位作者 Zhaohui Li Yuecheng Shen 《Journal of Innovative Optical Health Sciences》 SCIE EI 2019年第4期94-104,共11页
Feedback-based wavefront shaping focuses light through scattering media by employing phase optimization algorithms.Genetic algorithms(GAs),inspired by the process of natural selection,are well suited for phase optimiz... Feedback-based wavefront shaping focuses light through scattering media by employing phase optimization algorithms.Genetic algorithms(GAs),inspired by the process of natural selection,are well suited for phase optimization in wavelfront shaping problems.In 2012,Conkey et al.first introduced a GA into feedback-based wavefront shaping to find the optimum phase map.Since then,due to its siuperior performance in noisy environment,the GA has been widely adopted by lots of implementations.However,there have been limited studies discussing and optimizing the detailed procedures of the GA.To fill this blank,in this study,we performed a thorough study on the performance of the GA for focusing light through scattering media.Using numerical tools,we evaluated certain procedures that can be potentially improved and provided guidance on how to choose certain parameters appropriately.This study is beneficial in improving the performance of wavefront shaping systems with GAs. 展开更多
关键词 Genetice algorithm wavefront shaping scattering media adaptive optics
暂未订购 下载PDF
Three-year results of small incision lenticule extraction and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis for correction of high myopia and myopic astigmatism 认领 引用 被引量：24
17
作者 Li-Kun Xia Jing Ma +2 位作者 He-Nan Liu Ce Shi Qing Huang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2018年第3期470-477,共8页
AIM： To compare and calculate the 3-year refractive results, higher-order aberrations （HOAs）, contrast sensitivity （CS） and dry eye parameters after small incision lenticule extraction （SMILE） and wavefront-gui... AIM： To compare and calculate the 3-year refractive results, higher-order aberrations （HOAs）, contrast sensitivity （CS） and dry eye parameters after small incision lenticule extraction （SMILE） and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis （FS-LASIK） for correction of high myopia and myopic astigmatism. METHODS： In this prospective, non-randomized comparative study, 78 eyes with spherical equivalent （SE） of -8.11±1.09 diopters （D） received a SMILE surgery, and 65 eyes with SE of -8.05±1.12 D received a wavefront-guided FS-LASIK surgery with the VisuMax femtosecond laser （Carl Zeiss Meditec, Jena, Germany） for flap cutting. Visual acuity, manifest refraction, CS, HOAs, ocular surface disease index （OSDI） and tear break-up time （TBUT） were evaluated during a 3-year follow-up. RESULTS： The difference of uncorrected distance visual acuity （UDVA） postoperatively was achieved at lmo and at 3mo, whereas the difference of the mean UDVA between two groups at 3y were not statistically significant （t=-1.59, P=-0.13）. The postoperative change of SE was 0.89 D in the FS-LASIK group （t=5.76, P=0.00）, and 0.14 D in the SMILE group （t=-0.54, P=0.59） from lmo to 3y after surgery. At 3-year postoperatively, both HOAs and spherical aberrations in the SMILE group were obviously less than those in the FS-LASIK group （P=0.00）, but the coma root mean square （RMS） was higher in the SMILE group （0.59±0.26） than in the FS-LASIK group （0.29±0.14, P=0.00）. The mesopic CS values between two groups were not statistically significant at 3y postoperatively. Compared with the FS-LASIK group, lower OSDI scores and longer TBUT values were found in the SMILE group at Imo and 3mo postoperatively. With regard to safety, no eye lost any line of CDVA in both groups at 3y after surgery. CONCLUSION： Both SMILE and wavefront-guided FS- LASIK procedures provide good visual outcomes. Both procedures are effective and safe, but SMILE surgery achieve more stable long-term refractive outcome and better control of early postoperative dry eye as compared to FS-LASIK. 展开更多
关键词 small incision lenticule extraction wavefront-guided femtosecond laser-assisted laser in situ keratomileusis femtosecond laser refractive surgery visual outcome
暂未订购 下载PDF
Simple PSF based method for pupil phase mask’s optimization in wavefront coding system 认领 引用 被引量：2
18
作者 ZHANG Wen-zi CHEN Yan-ping +2 位作者 ZHAO Ting-yu YE Zi YU Fei-hong 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS 2007年第2期180-185,共6页
By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize f... By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize for the best pupil phase mask in ideal condition. Here one simple point spread function (PSF) based method with only the standard deviation method used to evaluate the PSF stability over the depth of focus is taken to optimize for the best coefficients of pupil phase mask in practical optical systems. Results of imaging simulations for optical systems with and without pupil phase mask are presented, and the sharpness of image is calculated for comparison. The optimized results showed better and much more stable imaging quality over the original system without changing the position of the image plane. 展开更多
关键词 Wavefront coding Pupil phase mask Depth of focus PSF stability Optimization Sharpness Imaging simulation
暂未订购 下载PDF
GLOBAL STABILITY OF TRAVELING WAVEFRONTS FOR NONLOCAL REACTION-DIFFUSION EQUATIONS WITH TIME DELAY 认领 引用 被引量：5
19
作者 杨兆星 张国宝 《Acta Mathematica Scientia》 SCIE CSCD 2018年第1期289-302,共14页
This paper is concerned with the stability of traveling wavefronts for a population dynamics model with time delay. Combining the weighted energy method and the comparison principle, the global exponential stability o... This paper is concerned with the stability of traveling wavefronts for a population dynamics model with time delay. Combining the weighted energy method and the comparison principle, the global exponential stability of noncritical traveling wavefronts （waves with speeds c 〉 c＊, where c=c＊ is the minimal speed） is established, when the initial perturbations around the wavefront decays to zero exponentially in space as x → -∞, but it can be allowed arbitrary large in other locations, which improves the results in[9, 18, 21]. 展开更多
关键词 nonlocal reaction-diffusion equations traveling wavefronts stability compari- son principle weighted energy method
暂未订购 下载PDF
Wavefront evolution of the signal beam in Ti:sapphire chirped pulse amplifier 认领 引用 被引量：1
20
作者 Zhen Guo Lianghong Yu +2 位作者 Wenqi Li Zebiao Gan Xiaoyan Liang 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第1期385-389,共5页
We studied the evolution of wavefront aberration(WFA) of a signal beam during amplification in a Ti:sapphire chirped pulse amplification(CPA) system. The results verified that the WFA of the amplified laser beam has l... We studied the evolution of wavefront aberration(WFA) of a signal beam during amplification in a Ti:sapphire chirped pulse amplification(CPA) system. The results verified that the WFA of the amplified laser beam has little relation with the change of the pump beam energies. Transverse parasitic lasing that might occur in CPA hardly affects the wavefront of the signal beam. Thermal effects were also considered in this study, and the results show that the thermal effect cumulated in multiple amplification processes also has no obvious influence on the wavefront of the signal beam for a single-shot frequency. The results presented in this paper confirmed experimentally that the amplification in a Ti:sapphire CPA system has little impact on the WFA of the signal beam and it is very helpful for wavefront correction of single-shot PW and multi-PW laser systems based on Ti:sapphire. 展开更多
关键词 wavefront aberration Ti:sapphire chirped pulse amplification wavefront correction
暂未订购 下载PDF
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
上一页 1 2 … 94 下一页 到第 页
在线咨询 使用帮助 返回顶部 意见反馈