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An Image Stabilization Optical System Using Deformable Freeform Mirrors

SENSORS 2015年第1期15卷 1736-1749页

作者： Hao, Qun Cheng, Xuemin Kang, Jiqiang Jiang, Yuhua Beijing Inst Technol Sch Optoelect Beijing Key Lab Precis Optoelect Measurement Inst Beijing 100081 Peoples R China Tsinghua Univ Grad Sch Shenzhen Shenzhen 518055 Peoples R China

An image stabilization optical system using deformable freeform mirrors is proposed that enables the ray sets to couple dynamically in the object and image space. It aims to correct image blurring and degradation when there is relative movement between the imaging optical axis and the object. In this method, Fermat's principle and matrix methods are used to describe the optical path of the entire optical system with a shift object plane and a fixed corresponding image plane in the carrier coordinate system. A constant optical path length is determined for each ray set, so the correspondence between the object and the shift free image point is used to calculate the solution to the points on the surface profile of the deformable mirrors (DMs). Off-axis three-mirror anastigmats are used to demonstrate the benefits of optical image stabilization with one-and two-deformable mirrors.

关键词： geometric optics computation methods stabilization system

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Near infrared adaptive optics flood illumination retinal angiography

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BIOMEDICAL OPTICS EXPRESS 2019年第6期10卷 2730-2743页

作者： Gofas-Salas, Elena Mece, Pedro Mugnier, Laurent Bonnefois, Aurelie Montmerle Petit, Cyril Grieve, Kate Sahel, Jose Paques, Michel Meimon, Serge Univ Paris Saclay ONIRA 1 01A F-91123 Palaiseau France Sorbonne Univ Inst Vis UPMC Univ Paris 06 INSERMCNRS 17 Rue Moreau F-75012 Paris France Paris Adapt Opt Retinal Imaging & Surg PARIS Grp Paris France Quantel Med Cournon Dauvergne France Quinze Vingts Hosp CIC 1423 INSERM Paris France Univ Pittsburgh Sch Med Dept Ophthalmol Pittsburgh PA USA

Image-based angiography is a well-adapted technique to characterize vasculature, and has been used in retinal neurovascular studies. Because the microvasculature is of particular interest, being the site of exchange between blood and tissue, a high spatio-temporal resolution is required, implying the use of adaptive optics ophthalmoscopes with a high frame rate. Creating the opportunity for decoupled stimulation and imaging of the retina makes the use of near infrared (NIR) imaging light desirable, while the need for a large field of view and a lack of distortion implies the use of a flood illumination-based setup. However, flood-illumination MR video sequences of erythrocytes, or red blood cells (RBC), have a limited contrast compared to scanning systems and visible light. As a result, they cannot be processed via existing image-based angiography methods. We have therefore developed a new computational method relying on a spatio-temporal filtering o f the sequence to isolate blood flow from noise in low-contrast sequences. Applying this computational approach enabled us to perform angiography with an adaptive optics flood illumination ophthalmoscope (AO-FIO) using MR light, both in bright-field and dark-field modalities. Finally, we demonstrate the capabilities of our system t o differentiate blood flow velocity on a retinal capillary network in vivo. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： computation methods Image metrics Image processing Retinal nerve fiber layer Scanning laser ophthalmoscopy Tissue

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Multiple phase extraction using graphics processing unit assisted unitary transformation method in digital holographic interferometry

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APPLIED OPTICS 2022年第28期61卷 8180-8189页

作者： Ramaiah, Jagadesh Gannavarpu, Rajshekhar Indian Inst Technol Dept Elect Engn Kanpur 208016 India Indian Inst Technol Ctr Lasers & Photon Kanpur 208016 India

The article presents a method to estimate multiple phase maps from a moire fringe signal obtained using digital holographic interferometry. The proposed method uses a unitary transformation based signal subspace approach, and shows high robustness against noise. In addition, the method facilitates the estimation of multiple phase maps in a single shot operation without the need for spectral filtering or multiple images. The computational efficiency of the method was improved by a high performance implementation using a graphics processing unit. The practical utility of the proposed method is demonstrated using simulation and experiment results.(c) 2022 Optica Publishing Group

关键词： computation methods Digital holographic imaging Holographic interferometry Phase estimation Phase measurement Phase retrieval

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Efficient optimal design of smooth optical freeform surfaces using ray targeting

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OPTICS COMMUNICATIONS 2013年 300卷 100-107页

作者： Wu, Rengmao Wang, Huihui Liu, Peng Zhang, Yaqin Zheng, Zhenrong Li, Haifeng Liu, Xu Zhejiang Univ State Key Lab Modern Opt Instrumentat Hangzhou 310027 Zhejiang Peoples R China

An optimization design method is proposed for generating smooth freeform reflective and refractive surfaces. In this method, two optimization steps are employed for ray targeting. The first step aims to ensure the shape of the target illumination, and the second step is employed to further improve the irradiance uniformity. These two steps can provide significant savings of time because the time consuming Monte Carlo raytracing is not used during the optimization process. Both smooth freeform reflective surfaces and smooth freeform refractive surfaces can be designed, and the target illumination could be achieved just by controlling the positions of several hundred predefined rays on the target plane with these two steps. The simulation results and the experimental tests show that this optimization design method is robust and efficient. (C) 2013 Elsevier B.V. All rights reserved.

关键词： Illumination design Aspherics Nonimaging optics computation methods

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Adaptive flat multiresolution multiplexed computational imaging architecture utilizing micromirror arrays to steer subimager fields of view

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APPLIED OPTICS 2006年第13期45卷 2884-2892页

作者： Christensen, MP Bhakta, V Rajan, D Mirani, T Douglas, SC Wood, SL Haney, MW So Methodist Univ Dept Elect Engn Dallas TX 75275 USA Santa Clara Univ Dept Elect Engn Santa Clara CA 95053 USA Univ Delaware Dept Comp Engn Newark DE 19716 USA

A thin, agile multiresolution, computational imaging sensor architecture, termed PANOPTES (processing arrays of Nyguist-limited observations to produce a thin electro-optic sensor), which utilizes arrays of microelectromechanical mirrors to adaptively redirect the fields of view of multiple low-resolution subimagers, is described. An information theory-based algorithm adapts the system and restores the image. The modulation transfer function (MTF) effects of utilizing micromirror arrays to steering imaging systems are analyzed, and computational methods for combining data collected from systems with differing MTFs are presented. (c) 2006 Optical Society of America.

关键词： computation methods computational imaging Image quality Image reconstruction Image sensors Imaging systems

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zOPT: an open source optical projection tomography system and methods for rapid 3D zebrafish imaging

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BIOMEDICAL OPTICS EXPRESS 2020年第8期11卷 4290-4305页

作者： Zhang, Hanqing Waldmann, Laura Manuel, Remy Boije, Henrik Haitina, Tatjana Allalou, Amin Uppsala Univ Div Visual Informat & Interact Dept Informat Mchnol S-75105 Uppsala Sweden SciLifeLab BioImage Informat Facil S-75105 Uppsala Sweden Uppsala Univ Dept Organismal Biol S-75236 Uppsala Sweden Uppsala Univ Dept Neurosci S-75124 Uppsala Sweden

Optical projection tomography (OPT) is a 3D imaging alternative to conventional microscopy which allows imaging of millimeter-sized object with isotropic micrometer resolution. The zebrafish is an established model organism and an important tool used in genetic and chemical screening. The size and optical transparency of the embryo and larva makes them well suited for imaging using OPT. Here, we present an open-source implementation of an OPT platform, built around a customized sample stage, 3D-printed parts and open source algorithms optimized for the system. We developed a versatile automated workflow including a two-step image processing approach for correcting the center of rotation and generating accurate 3D reconstructions. Our results demonstrate high-quality 3D reconstruction using synthetic data as well as real data of live and fixed zebrafish. The presented 3D-printable OPT platform represents a fully open design, low-cost and rapid loading and unloading of samples. Our system offers the opportunity for researchers with different backgrounds to setup and run OPT for large scale experiments, particularly in studies using zebrafish larvae as their key model organism. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： computation methods Image processing Image quality Image reconstruction Reconstruction algorithms Three dimensional imaging

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Binary classification of Mueller matrix images from an optimization of Poincare coordinates

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JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION 2017年第6期34卷 983-990页

作者： Kupinski, Meredith K. Bankhead, Jaden Stohn, Adriana Chipman, Russell Univ Arizona Coll Opt Sci Tucson AZ 85721 USA

A new binary classification method for Mueller matrix images is presented which optimizes the polarization state analyzer (PSA) and the polarization state generator (PSG) using a statistical divergence between pixel values in two regions of an image. This optimization generalizes to multiple PSA/PSG pairs so that the classification performance as a function of number of polarimetric measurements can be considered. Optimizing PSA/PSG pairs gives insight into which polarimetric measurements are most useful for the binary classification. For example, in scenes with strong diattenuation, retardance, or depolarization certain PSA/PSG pairs would make two regions in an image look very similar and other pairs would make the regions look very different. The method presented in this paper provides a quantitative method for ensuring the images acquired can be classified optimally. (C) 2017 Optical Society of America

关键词： computation methods Medical imaging Mueller matrices Optical elements Optical testing Phase sensitive amplifiers

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Comparison between the pseudo-spectral time domain method and the discrete dipole approximation for light scattering simulations

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OPTICS EXPRESS 2012年第15期20卷 16763-16776页

作者： Liu, Chao Bi, Lei Panetta, R. Lee Yang, Ping Yurkin, Maxim A. Texas A&M Univ Dept Atmospher Sci College Stn TX 77843 USA Inst Chem Kinet & Combust SB RAS Novosibirsk 630090 Russia Novosibirsk State Univ Novosibirsk 630090 Russia

The pseudo-spectral time domain (PSTD) and the discrete dipole approximation (DDA) are two popular and robust methods for the numerical simulation of dielectric particle light scattering. The present study compares the numerical performances of the two methods in the computation of the single-scattering properties of homogeneous dielectric spheres and spheroids for which the exact solutions can be obtained from the Lorenz-Mie theory and the T-matrix theory. The accuracy criteria for the extinction efficiency and the phase function are prescribed to be the same for the PSTD and DDA in order that the computational time can be compared in a fair manner. The computational efficiency and applicability of the two methods are each shown to depend on both the size parameter and the refractive index of the scattering particle. For a small refractive index, a critical size parameter, which decreases from 80 to 30 as the refractive index increases from 1.2 to 1.4, exists below which the DDA outperforms the PSTD. For large refractive indices (>1.4), the PSTD is more efficient than the DDA for a wide size parameter range and has a larger region of applicability. Furthermore, the accuracy shown by the two methods in the computation of backscatter, linear polarization, and asymmetry factor is comparable. The comparison was extended to include spheroids with typical refractive indices of ice and dust and similar conclusions were drawn. (C) 2012 Optical Society of America

关键词： computation methods Electromagnetic scattering Light scattering Numerical simulation Particle scattering Refractive index

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3D integral imaging display by smart pseudoscopic-to-orthoscopic conversion (SPOC)

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OPTICS EXPRESS 2010年第25期18卷 25573-25583页

作者： Navarro, H. Martinez-Cuenca, R. Saavedra, G. Martinez-Corral, M. Javidi, B. Univ Valencia Dept Opt E-46100 Burjassot Spain Univ Connecticut Dept Elect & Comp Engn Storrs CT 06269 USA

Previously, we reported a digital technique for formation of real, non-distorted, orthoscopic integral images by direct pickup. However the technique was constrained to the case of symmetric image capture and display systems. Here, we report a more general algorithm which allows the pseudoscopic to orthoscopic transformation with full control over the display parameters so that one can generate a set of synthetic elemental images that suits the characteristics of the Integral-Imaging monitor and permits control over the depth and size of the reconstructed 3D scene. (C) 2010 Optical Society of America

关键词： computation methods Integral imaging Integral photography Three dimensional displays Three dimensional imaging Three dimensional reconstruction

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Global optimization and modeling techniques for planar multilayered dielectric structures

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APPLIED OPTICS 2006年第23期45卷 5910-5922页

作者： Oulton, R. F. Adjiman, C. S. Univ London Imperial Coll Sci Technol & Med Dept Chem Engn Ctr Proc Syst Engn London SW7 2BZ England

We present a multilevel global optimization strategy for synthesizing planar multilayered dielectric structures. A low discrepancy sequence of sample points with uniform variable space coverage allows a global-level search while systematic refinement using gradient-based techniques identifies optima at the local level. Since efficient local optimization is important for this method, a fast calculation approach based on mode matching is presented;this also facilitates the compact derivation of analytical gradients. The approach is compared with genetic and simulated annealing algorithms through an antireflection coating design. The method proves to be competitive in terms of its performance, nonadaptive algorithm, and ability to track local solutions. (C) 2006 Optical Society of America.

关键词： Antireflection coatings Bragg reflectors computation methods Genetic algorithms Optical design Semiconductor lasers

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