检索结果-内蒙古大学图书馆

Video-rate lensless endoscope with self-calibration using wavefront shaping

OPTICS LETTERS 2020年第13期45卷 3629-3632页

作者： Scharf, Elias Dremel, Jakob Kuschmierz, Robert Czarske, Juergen Tech Univ Dresden Lab Measurement & Sensor Syst Tech Dresden Germany

Lensless fiber endoscopes are of great importance for keyhole imaging. Coherent fiber bundles (CFB) can be used in endoscopes as remote phased arrays to capture images. One challenge is to image at high speed while correcting aberrations induced by the CFB. We propose the combination of digital optical phase conjugation, using a spatial light modulator, with fast scanning, for which a 2D galvo scanner and an adaptive lens are employed. We achieve the transmission of laser and image scanning through the CFB. Video-rate imaging at 20 Hz in 2D with subcellular resolution is demonstrated in 3D with 1 Hz. The sub-millimeter-diameter scanning endoscope has a great potential in biomedicine, for manipulation, e.g., in optogenetics, as well as in imaging. (C) 2020 Optical Society of America

关键词： Fiber bundles image processing algorithms Laser scanning Phase conjugation Phased arrays Scanners

来源：评论

学校读者我要写书评

暂无评论

Computational nanosensing from defocus in single particle interferometric reflectance microscopy

引用

OPTICS LETTERS 2020年第23期45卷 6546-6549页

作者： Yurdakul, Celalettin Unlu, M. Selim Boston Univ Dept Elect & Comp Engn Boston MA 02215 USA Boston Univ Dept Biomed Engn Boston MA 02215 USA

Single particle interferometric reflectance (SPIR) microscopy has been studied as a powerful imaging platform for label-free and highly sensitive biological nanoparticle detection and characterization. SPIR's interferometric nature yields a unique 3D defocus intensity profile of the nanoparticles over a large field of view. Here, we utilize this defocus information to recover high signal-to-noise ratio nanoparticle images with a computationally and memory efficient reconstruction framework. Our direct inversion approach recovers this image from a 3D defocus intensity stack using the vectorial-optics-based forward model developed for sub-diffraction-limited dielectric nanoparticles captured on a layered substrate. We demonstrate proof-of-concept experiments on silica beads with a 50 nm nominal diameter. (C) 2020 Optical Society of America

关键词： High numerical aperture optics image processing algorithms image quality Imaging techniques Optical imaging Three dimensional imaging

来源：评论

学校读者我要写书评

暂无评论

Light field camera study of near-ground turbulence anisotropy and observation of small outer-scales

引用

OPTICS LETTERS 2020年第5期45卷 1156-1159页

作者： Wu, Chensheng Paulson, Daniel A. Rzasa, John R. Davis, Christopher C. Univ Maryland Elect & Comp Engn Dept College Pk MD 20742 USA Univ Maryland Bioengn Dept College Pk MD 20742 USA Univ Maryland Fischell Inst Biomed Devices College Pk MD 20742 USA

Understanding turbulence effects on laser beam propagation is critical to the emerging design, study, and test of many long-range free space optical (FSO) communication and directed energy systems. Conventional studies make the prevalent assumption of isotropic turbulence, while more recent results suggest anisotropic turbulence for atmospheric channels within a few meters elevation above the ground. As countless FSO systems have been and continue to be deployed in such channels, analysis of anisotropic modelings has become one of the fastest growing areas in FSO research. This in turn motivates new tools that can distinguish anisotropic characteristics to improve both modeling accuracy and physical interpretations. Wavefront sensors such as Shack-Hartmann sensors, interferometers, and plenoptic sensors have been devised and used in experiments;however, they all require rigid alignments that lack resilience against temperature gradient buildup and beam wander. We find that by using a light field camera (LFC) that extracts perturbation of individual light rays, the wave structure function of turbulence can be retrieved with high reliability. Furthermore, we find through experiments that the outer scales of near-ground turbulence tend to be a magnitude smaller than conventional theoretical assumptions, agreeing with new findings by others but being absent in current theoretical modelings. As a result, we believe that the LFC is an ideal candidate in the frontier of turbulence research;it is both commercially available and easy to adapt to turbulence experiments. (C) 2020 Optical Society of America

关键词： Atmospheric turbulence image processing algorithms Laser beam propagation Plenoptic imaging Power spectral density Turbulence effects

来源：评论

学校读者我要写书评

暂无评论

Compensation method for projector calibration based on homography and bundle adjustments

引用

OSA CONTINUUM 2020年第11期3卷 3157-3175页

作者： Lin, Junyi Zhang, Xuefeng Wang, Yushu Wu, Lei Jiang, Kaiyong Huaqiao Univ Fujian Prov Key Lab Special Energy Mfg Xiamen Key Lab Digital Vis Measurement Xiamen 361021 Fujian Peoples R China

Projector calibration is one of the most essential steps for structured light systems. Some methods have high precision but require a complicated calibration procedure, such as the method based on phase-shifting. Other methods take advantage of simple implementation but cannot meet the accuracy requirement, for example, the method based on homography. In this paper, we proposed a compensation method for flexible and accurate projector calibration. To make the calibration procedure easy to operate, the homographic matrix between the projector and camera is established through feature points projected. Then, the 2D image points compensation method based on the re-projection error iteration algorithm was carried out, and a modified bundle adjustment (BA) algorithm is put forward to refine the calibration parameters of the system. Finally, the feature point reconstruction experiment is implemented to verify the high flexibility and accuracy performance of the proposed method. (c) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： Calibration Digital image correlation image processing algorithms Stereo matching Structured light Virtual reality

来源：评论

学校读者我要写书评

暂无评论

Sub-pixel dimensional measurement algorithm based on intensity integration threshold

引用

OSA CONTINUUM 2020年第10期3卷 2912-2924页

作者： Chu, Menglin Huang, Wei Xu, Mingfei Jia, Shuqiang Zhang, Xiaofei Lu, Yongnan Chinese Acad Sci Changchun Inst Opt Fine Mech & Phys 3888 Dong Nanhu Rd Changchun 130033 Peoples R China Univ Chinese Acad Sci 19 A Yuquan Rd Beijing 100049 Peoples R China Changchun Univ Sci & Technol 7089 Weixing Rd Changchun 130022 Peoples R China Chinese Acad Sci Dalian Inst Chem Phys 457 Zhongshan Rd Dalian 116023 Peoples R China

In this paper, we proposed a sub-pixel measurement algorithm based on intensity integration threshold (IIT). The proposed method can localize the sub-pixel edges in an inexpensive way by calculating the integration of the intensity across the edge and finding the point where the integration reaches the threshold. Comparative tests show our method realized better efficiency and robustness in practical applications than other state-of-the-art algorithms. (c) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： algorithms Edge detection image processing image processing algorithms Machine vision Wavelet transforms

来源：评论

学校读者我要写书评

暂无评论

Microscope-type laser speckle contrast imaging for in vivo assessment of microcirculation

引用

OSA CONTINUUM 2020年第5期3卷 1129-1137页

作者： Lee, Cheng-Yu Huang, Bo-Huei Chen, Wen-Ju Yi, Jui-Yun Tsai, Meng-Tsan Chang Gung Univ Dept Elect Engn Taoyuan 33302 Taiwan Natl Kaohsiung Normal Univ Dept Optoelect & Commun Engn Kaohsiung Taiwan Chang Gung Mem Hosp Dept Neurosurg Linkou 33305 Taiwan

Laser speckle contrast imaging (LSCI) can be used to observe dynamic changes in the tissue microcirculation in vivo according to the dynamic interaction between red blood cells and coherent light. In this study, a dual-wavelength LSCI system based on a microscope was developed for in vivo observation of the microvascular pattern and measurement of the blood flow change in the animal model. Additionally, based on the dual-wavelength setup, including 635 and 855 nm wavelengths, the oxygenation of biological tissue was evaluated. Finally, the developed LSCI microscope was implemented for the studies of tissue microcirculation. The results indicate that the developed LSCI microscope could be a potential tool for in vivo observation of the tissue microcirculation and quantitative evaluation of hemodynamics in animal experiments. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： Diode lasers image processing algorithms image quality In vivo imaging Speckle imaging Tissue

来源：评论

学校读者我要写书评

暂无评论

Fringe visibility errors resulting from dual object imaging for stellar interferometers

引用

APPLIED OPTICS 2021年第25期60卷 G207-G216页

作者： Snyder, Joshua Bailey, Christopher Schmoll, Walter Zuraski, Steven Beecher, Elizabeth Leidos Beavercreek OH 45431 USA Force Res Lab Sensors Directorate Dayton OH 45433 USA

Practical stellar interferometry for space domain awareness is challenged by the relative motions of orbital objects and telescope arrays that require array phasing using guide stars. Anorbital object's image sensitivity to the location and brightness of the guide star is problematic, possibly resulting in a degraded resolution or loss of image content when both objects fall within the interferometer's field of view. We characterized an orbital object's visibility using visibility contrast to noise ratios (CNR Delta v) as a performance metric for orbital object image quality. Experimental validations included orbital object visibility measurements for dual binary pinholes that were scaled in size and brightness individually to match expected interferometer data collection scenarios. We show agreement in CNR Delta v results, indicating resolvable orbital object signals during periods of collection when signal contributions from both the orbital object and guide star are present. Expanding presented results to imaging interferometers, we discuss how dual object imaging could degrade performance under the scenarios examined. (C) 2021 Optical Society of America

关键词： Diffraction limit image processing algorithms image quality image reconstruction Power spectral density Stellar interferometry

来源：评论

学校读者我要写书评

暂无评论

A compact photonic resonator absorption microscope for point of care digital resolution nucleic acid molecular diagnostics (vol 12, pg 4637, 2021)

引用

BIOMEDICAL OPTICS EXPRESS 2021年第8期12卷 5159-5159页

作者： Ghosh, Shreya LI, Nantao Xiong, Yanyu Ju, Young-gu Rathslag, Michael P. Onal, Ege G. Falkiewicz, Erika Kohli, Manish Cunningham, Brian T. Univ Illinois Holonyak Micro & Nanotechnol Lab Urbana IL 61801 USA Univ Illinois Dept Elect & Comp Engn Urbana IL 61801 USA Kyungpook Natl Univ Dept Phys Educ 80 Daehak Ro Daegu South Korea Univ Illinois Dept Bioengn Urbana IL 61801 USA Univ Illinois Sch Integrat Biol Urbana IL 61801 USA Univ Utah Huntsman Canc Inst Salt Lake City UT 84112 USA Univ Illinois Carl R Woese Inst Genom Biol Urbana IL 61801 USA Univ Illinois Canc Ctr Illinois Urbana IL 61809 USA

This publisher’s notes amends the funding of [Biomed. Opt. Express 12 , 4637 (2021 )10.1364/BOE.427475 ].

关键词： High numerical aperture optics image processing algorithms Molecular diagnostics Polarized light Red light emitting diodes Surface plasmons

来源：评论

学校读者我要写书评

暂无评论

High speed vocal fold imaging using smartphone-based laryngoscope: A preliminary study

High speed vocal fold imaging using smartphone-based laryngo...

引用

Conference on Lasers and Electro-Optics (CLEO)

作者： Kim, YoungKyu Oh, Jeongmin Choi, Seung-ho Jung, Ah Ra Lee, Yoon Se Lee, June-Goo Kim, Jun Ki Asan Med Ctr Asan Inst Life Sci Biomed Engn Res Ctr 88 Olymp Ro43 Gil Seoul 05505 South Korea Univ Ulsan Dept Convergence Med Coll Med Ulsan South Korea Univ Ulsan Coll Med Asan Med Ctr Dept Otolaryngol Seoul South Korea

ISBN: (数字)9781943580767

ISBN: (纸本)9781943580767

In recent, performances of smartphones are highly developed and they can acquire high resolution image with high framerates. The objective of this study is the development of smartphone-based laryngoscope to reduce the cost of device and demonstrate possibility of highspeed vocal cord imaging by utilizing high performance smartphone camera. We designed customized smartphone adapter for combining clinical laryngoscope and Samsung smartphone. By attaching conventional clinical probes into our customized smartphone adaptor, the high- speed vocal cord endoscopic images were acquired. We could confirm the high-speed digital images of 940fps were acquired from 5 healthy volunteers as a preliminary study. (C) 2020 The Author(s)

关键词： Clinical applications Endoscopic imaging High speed imaging image processing algorithms image sensors Spatial resolution

来源：评论

学校读者我要写书评

暂无评论

A gain-enhanced silicon-photonic optical phased array with integrated O-band amplifiers for 40-m ranging and 3D scan

A gain-enhanced silicon-photonic optical phased array with i...

引用

Conference on Lasers and Electro-Optics (CLEO)

作者： Byun, Hyunil Lee, Jisan Jang, Bongyong Lee, Changbum Lee, Eunkyung Hwang, Inoh Shin, Changgyun Shin, Dongjae Shim, Dongshik Otsuka, Tatsuhiro Hwang, Sungwoo Choo, Hyuck Ha, Kyoungho Samsung Adv Inst Technol Samsung Elect 130 Samsung Ro Suwon South Korea

For the first time, we demonstrate 40-m range detection and 3D depth scan up to 20 m using a silicon-photonic optical phased array with integrated amplifiers, promising a high-performance solid-state light-detection a... 详细信息

ISBN: (数字)9781943580767

ISBN: (纸本)9781943580767

关键词： Grating couplers image processing algorithms Laser beams Phased arrays Range finding Tunable lasers

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：