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Potential vision tester using adaptive optics, Maxwellian view, and small pupil

BIOMEDICAL OPTICS EXPRESS 2023年第12期14卷 6397-6409页

作者： Elsner, Ann Papay, Joel Parimi, Vamsi Jung, Hae Won Clark, Christopher Burns, Stephen Gast, Thomas Indiana Univ Sch Optometry Bloomington IN 47405 USA Aeon Imaging LLC Bloomington IN 47403 USA

We demonstrate a free-space, trolley-mounted potential vision tester (PVT), designed to study and improve the accuracy of visual acuity (VA) measurements in the aging eye. Key features include a high-resolution visual display presented in Maxwellian view, a 3 mm pupil to limit wavefront (WF) aberrations, and a moderate cost deformable mirror to induce or correct higher order optical aberrations. The visual display supported accurate measurement of visual acuities down to 20/5. The moderate cost, piezo deformable mirror induced seven nominal aberrations, calibrated as 0,-0.32,-0.23, + 0.27, and +0.39 microns spherical aberration;+ 0.49 microns Y coma;and-0.51 microns X coma. A custom Hartmann Shack (HS) calibration (HSc) system demonstrated that induced aberrations were repeatable and stable. A Badal optometer provided the coarse focus. WF aberrations were measured for five normal subjects with a commercially available HS device (HSP) (OCULUS Pentacam AXL Wave), providing estimates of WF errors for 3 mm and other pupil sizes. VA was measured using four alternative forced-choice for a single black on white E stimulus in each trial. Using the method of constant stimuli yielded robust standard deviation measurements. The 50% fit for VA plotted against induced aberration resulted in linear functions for each subject for the range of our positive and negative spherical aberration data. Subjects differed, but higher order terms were unnecessary to describe data across spherical aberrations. (c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： Adaptive optics Deformable mirrors modulation transfer function Optical aberration Optical systems Spherical aberration

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Real-time on-orbit image quality improvement for a wide-field imaging system with detector arrays

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OPTICS EXPRESS 2023年第13期31卷 22204-22224页

作者： Zhou, Dali Wang, Xiaodong Yan, Changxiang Wang, Haihong Chinese Acad Sci Changchun Inst Opt Fine Mech & Phys Changchun 130033 Peoples R China Chinese Acad Sci CAS Key Lab Onorbit Mfg & Integrat Space Opt Syst Changchun Inst Opt Fine Mech & Phys Changchun 130033 Jilin Peoples R China Beijing Inst Tracking & Commun Technol Beijing 100094 Peoples R China

Wide-field imaging systems are faced with the problem of massive image information processing and transmission. Due to the limitation of data bandwidth and other factors, it is difficult for the current technology to process and transmit massive images in real-time. With the requirement for fast response, the demand for real-time on-orbit image processing is increasing. In practice, nonuniformity correction is an important preprocessing step to improve the quality of surveillance images. This paper presents a new real-time on-orbit nonuniform background correction method, which only uses the local pixels of a single row output in real-time, breaking the dependence of the traditional algorithm on the whole image information. Combined with the FPGA pipeline design, when the local pixels of a single row are read out, the processing is completed, and no cache is required at all, which saves the resource overhead in hardware design. It achieves microsecond-level ultra-low latency. The experimental results show that under the influence of strong stray light and strong dark current, our real-time algorithm has a better image quality improvement effect compared with the traditional algorithm. It will greatly help the on-orbit real-time moving target recognition and tracking.& COPY;2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： Genetic algorithms Image processing Image quality Imaging systems modulation transfer function Stray light

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Study of the image motion compensation method for a vertical orbit dynamic scanning TDICCD space camera

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OPTICS EXPRESS 2023年第25期31卷 41740-41755页

作者： Zhang, Guoxiu Xu, Youfu Liu, Chunyu Xie, Peng Ma, Wenjia Lu, Yibo Kong, Xianren Harbin Inst Technol Res Ctr Satellite Technol Harbin 150001 Heilongjiang Peoples R China Beijing Inst Tracking & Telecommun Technol Beijing 100083 Peoples R China Chinese Acad Sci Changchun Inst Opt Fine Mech & Phys Changchun 130033 Jilin Peoples R China Chinese Acad Sci Key Lab Space Based Dynam & Rapid Opt Imaging Tech Changchun 130033 Jilin Peoples R China Shanghai Inst Satellite Engn Shanghai 200240 Peoples R China

In this study, a collaborative compensation method for low-dimensional attitude maneuvering and time delay integration charge-coupled device (TDICCD) line-frequency matching is proposed. The method is combined with the validation and analysis of the coordinate system transformation model to address the mismatch between the TDI charge transfer speed and the speed of the target. This mismatch is caused by the inconsistency between the rotational scanning direction of the double-sided mirror used for dynamic vertical orbit scanning imaging in low Earth-orbit satellites and the direction of the satellite along its orbit. The image motion per unit exposure time is decreased from 0.619 mu m to 0.023 mu m compared with the uncompensated maneuver mode, and the image quality is noticeably higher.

关键词： Charge-coupled devices Imaging systems Imaging techniques modulation transfer function Nodal aberration theory Optical systems

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Spatial and directional contrast dependence in Lissajous-scanning projection systems

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OPTICS EXPRESS 2023年第12期31卷 20019-20033页

作者： Bainschab, Markus Pribosek, Jaka Silicon Austria Labs GmbH Photon Syst Europa str 12 A-9524 Villach Austria

Scanning-based image formation fundamentally differs from its classical lens-based counterpart. Therefore, established classical performance evaluation methods fail to determine the theoretical limitations of scanning-based optical systems. We developed a simulation framework and a novel performance evaluation process to evaluate the achievable contrast in scanning systems. Applying these tools, we conducted a study determining the resolution limits of different Lissajous scanning approaches. For the first time, we identify and quantify spatial and directional dependencies of the optical contrast and demonstrate their significant impact on the perceived image quality. We prove that the observed effects are more pronounced for Lissajous systems with high ratios of the two scanning frequencies. The presented method and results can lay the foundation for a more sophisticated application-specific design of next-generation scanning systems. & COPY;2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： Atomic force microscopy Image quality Imaging systems Magnetic resonance imaging modulation transfer function Projection systems

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Design of polythiourethane (PTU) polymer contact lens to correct the longitudinal chromatic aberration

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JOURNAL OF OPTICS-INDIA 2024年 1-5页

作者： Al-Hamdani, Ali H. Aljuboury, A. S. Hashim, Halah A. Mohammed, Dunya Zeki Lafta, Shakir M. Al-hamdani, H. A. Gilgamesh Univ Baghdad Iraq Baghdad Hlth Directorate Al Karkh Minist Hlth Baghdad Iraq Dijla Univ Opt Tech Dept Baghdad Iraq Arkansas Univ Engn & Engn Technol Sch DCSTEM Little Rock Arkansas AR 72707 USA Kerbala Univ Engn Coll Elect & Comp Engn Dept Kerbala Iraq

The manufacture of contact lenses is a highly accurate process that focuses on selecting appropriate material prescribed by specialists to eliminate certain vision defects, such as spherical and chromatic aberrations. The chosen materials should include main optical parameters (i.e., index of refraction, Abbe number, and materials transmittance). In this research, two polymers materials are used as contact lenses to eliminate or reduces these aberrations;the first is the polythiourethane (PTU), with refractive index (1.67) and Abbe number (28), and the second is the allyl carbonate (CR-39) with (1.49 and 58 ) index of refraction and Abbe number (58), respectively. The image performance of the human eye with these contact lenses was calculated and compared with the healthy eye ( without contact lens ), with the help of lens design software Zemax-EE, based on the Liou and Brennan model. The vision for the eye with different eye pupil diameters (1, 25, 2, 3, and 4 mm) and field of view (5, 10, 20, 30, 40, 50, 60 degrees) are studied and analysed. This analysis depended on the essential criteria, such as modulation transfer function (MTF), encircled energy (EE), and the longitudinal focal shift. The results indicated that the PTU polymer exhibits excellent optical properties and can be considered a prominent optical polymer used in ophthalmic contact lenses.

关键词： Contact lens material Chromatic aberration modulation transfer function Polythiourethane PTU Image quality analysis

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Broadband lens and graphene/silicon photodiode for wide spectral imaging

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OPTICS LETTERS 2024年第3期49卷 518-521页

作者： Wang, Jiafu Dai, Yue Cao, Xiaoxue Li, Zongwen Xu, Xinyi Bodepudi, Srikrishna C. Fang, Wenzhang Chen, Yance Ren, Yaqi Hao, Xiujun Lu, Xujie Shen, Hui-Liang Li, Zheng Yuan, Xin Hu, Huan Zhang, Qigong Sun, Zhi-Pei Xu, Yang Zhejiang Univ Sch Micronano Elect ZJU HIC ISEE Hangzhou 310027 Peoples R China Zhejiang Univ State Key Lab Silicon Mat Hangzhou 310027 Peoples R China Hangzhou Hikmicro Sensing Technol Co Ltd Hangzhou 311599 Peoples R China Westlake Univ Hangzhou 310024 Peoples R China Aalto Univ Dept Elect & Nanoengn Espoo Finland Aalto Univ QTF Ctr Excellence Dept Appl Phys Espoo Finland

We designed a broadband lens along with a graphene/silicon photodiode for wide spectral imaging ranging from ultraviolet to near -infrared wavelengths. By using five spherical glass lenses, the broadband lens, with the modulation transfer function of 0.38 at 100 lp/mm, corrects aberrations ranging from 340 to 1700 nm. Our design also includes a broadband graphene/silicon Schottky photodiode with the highest responsivity of 0.63 A/W ranging from ultraviolet to nearinfrared. By using the proposed broadband lens and the broadband graphene/silicon photodiode, several single -pixel imaging designs in ultraviolet, visible, and near -infrared wavelengths are demonstrated. Experimental results show the advantages of integrating the lens with the photodiode and the potential to realize broadband imaging with a single set of lens and a detector. (c) 2024 Optica Publishing Group

关键词： Diffractive lenses Imaging systems Lens design modulation transfer function Optical systems Single pixel imaging

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Polychromatic visual performance of different hologram multifocal hybrid intraocular lenses implanted within the human eye

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JOURNAL OF OPTICS-INDIA 2025年

作者： Al-Hamdani, Ali H. Hashem, Hadeel T. Hussein, Mohammad A. R. Rashid, Hayfa G. Dawood, Yasmeen Z. Aljuboury, Anwer S. Al-Hamdani, H. A. Gilgamesh Univ Coll Sci Baghdad Iraq Univ Technol Baghdad Dept Laser & Optoelect Engn Baghdad Iraq Minist Educ Iraq Directorate Gen Educ Diwaniya Baghdad Iraq Mustansiryah Univ Coll Educ Dept Phys Baghdad Iraq Univ Al Qadisiyah Coll Sci Med Phys Diwaniyah Iraq Mustansiryah Univ Baghdad Iraq Univ Karbala Elect & Elect Engn Dept Karbala Iraq Henderson State Univ Engn & Phys Dept Arkadelphia AR USA

The retinal image was strongly affected by chromatic and spherical aberrations. In this contribution, the optical quality and chromatic performance of hybrid (refractive-diffractive) multifocal intraocular lenses (MIOL) are designed to reduce chromatic aberrations. Four hybrid IOLs and holographic optical elements (HOEs) embedded in a refractive lens were evaluated. In this study, the human eye was implanted by one of the following hybrid multifocal length MIOL: A hologram/refractive (H/R), hologram/diffractive (H/D);refractive/hologram (R/H), and diffractive/hologram (D/R). Visual performance was assessed in white and green light at a pupil diameter of 3 mm and a field of view of 5 degrees. A single-layer coating from Poly(ethylene glycol) (PEG) in (QWOT) on the hologram surface was used. Using the Liou-Brennan eye model, the human eye was simulated to access vision quality, modulation transfer function (MTF), point spread function (PSF), chromatic focal shift (LCA), image spot size (RMS), and longitudinal aberrations (LSA). The present results were compared with and without (MIOLs). Results indicate that for all hybrid-hologram MIOL implanted within the eye model, an improvement in visual performance associated with the correction in longitudinal chromatic (45-55%) and longitudinal monochromatic aberration(55-65%) as compared with that of the healthy eye model. Similarly, the Strehl ratio for all cases is approximately equal to the Marshal's value for the perfect optical system (0.8). The MTF with D/H hybrid MIOL has a higher value. The Strehl ratio for all cases is approximately equal to the Marshal's value for the perfect optical system (0.8). The MTF at 50 (MTF50), at 150 (MTF150), and 200 (MTF200) cycle/mm for the eye with D/H hybrid MIOL has a higher value for both the Sagit1tal and Tangential MTF. 0.776, 0.368, 0.213, and 0.754, 0.287, 0.135), compared with that for Liou- Brennan model MTF (0.765, 0.351, 0.200, and 0.724, 0.270, 0.127), respectively. The vis

关键词： Hybrid multifocal intraocular lens Hologram MIOLs Vision quality modulation transfer function Chromatic aberration Difractive optics

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Dual mode, imaging infrared and semi-active laser, seeker design with squinted combined diffractive optical element

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JOURNAL OF OPTICS-INDIA 2024年第5期53卷 4594-4615页

作者： Unal, A. Middle East Tech Univ METU Dept Elect & Elect Engn Ankara Turkiye

Diffractive optical elements are becoming increasingly popular due to their ability to provide a broad spectrum of design possibilities by manipulating Fresnel regions. These design capabilities enable the simultaneous accomplishment of various functions in electro-optical systems using a single optical element. This study presents novel dual-mode seeker design approaches incorporating squinted combined diffractive optical element (SCDOE) that allow us to combine two seeker types into one in a common aperture design. Multiple systems function in a multi-spectral detection and imaging manner combined with the usage of the SCDOE. The creation of the squinted diffractive lens, allows the seeker to operate in two modes simultaneously. In the first mode, the seeker functions as a traditional laser seeker, benefitting from enhanced measurement sensitivity and measurement range. In the second mode, with the aid of the squinted design of the SCDOE, the systems operate as imagers in the extended short-wave infrared (eSWIR) or long-wave infrared (LWIR) bands. The principle of operation of the seeker modes was simulated separately. The laser seeker simulation results were compared with the ideal lens having similar optical parameters. The imaging seekers (eSWIR, LWIR, and eSWIR/LWIR) were compared using fusion algorithms with the peak signal-to-noise ratio (PSNR), structural similarity index (SSIM) and system contrast transfer function (CTF). The assessment of the fusion algorithms in the eSWIR/LWIR seeker with the separated eSWIR and LWIR imagers indicates that the contrast pyramid algorithm (CP) gives the best result in target detection in terms of CTF. Besides this, the imaging capability of dual mode, a laser with imaging, gives superior measurement sensitivity, +/- 0.6 mrad, in comparison with the laser seeker. As a result, the SCDOE in a dual-mode seeker combines the two electro-optical systems into one. The findings of this study make a substantial contribution to the p

关键词： Electro-optical systems Multi-band imaging Multi-spectral imaging Image fusion Combined diffractive lens Contrast transfer function modulation transfer function Point spread function Contrast to noise ratio

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Derivation and calibration of spectral response for a channeled spectropolarimeter

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OPTICS EXPRESS 2023年第16期31卷 25763-25780页

作者： Zhao, Zhe Li, Yanqiu Liu, Ke Zhou, Guodong Beijing Inst Technol Minist Educ China Sch Opt & Photon Key Lab Photoelect Imaging Technol & Syst 5 South Zhongguancun St Beijing 100081 Peoples R China

The channeled spectropolarimeter (CSP) measures the spectrally-resolved Stokes vector from a snapshot by employing spectral modulation. The spectral modulation transfer function (SMTF) of the spectrometer preferentially suppresses the high-frequency channel amplitude in CSP, resulting in reduced measurement accuracy. This paper rigorously derives the SMTF theory and proposes an efficient calibration method for SMTF via channel shifting in a CSP. The SMTF value, obtained by channel shifting, is used to correct the high-frequency channel amplitude. Moreover, alignment and phase errors, as well as nonlinear dispersion, are compensated in situ. Other than rotating the retarder twice, no additional instruments or algorithms are required in the proposed method. In simulations and experiments, the proposed method shows high accuracy, with a maximum root-mean-square error (RMSE) of the reconstructed Stokes spectrum below 0.01, demonstrating its potential for enhancing the simplicity and practicability of Stokes CSP.& COPY;2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： Calibration Michelson interferometers modulation transfer function Neural networks Remote sensing White light interferometry

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Quantitative evaluation of refractive index inhomogeneity and its effect on the imaging performance of high-precision injection molded optical lens

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JOURNAL OF MANUFACTURING PROCESSES 2023年 101卷 1605-1615页

作者： Zhou, Xiaowei He, Jian Li, Maoyuan Zhang, Yun Zhao, Peng Chen, Yuhong Liu, Feng Zhou, Huamin Huazhong Univ Sci & Technol Sch Mat Sci & Engn State Key Lab Mat Proc & Die & Mould Technol Wuhan 430074 Peoples R China Harbin Inst Technol Natl Key Lab Precis Hot Proc Met Harbin 150001 Peoples R China Zhejiang Univ Coll Mech Engn State Key Lab Fluid Power & Mechatron Syst Hangzhou 310027 Peoples R China Beijing Inst Aeronaut Mat Beijing 100095 Peoples R China Zhejiang Univ Water Resources & Elect Power Coll Mech & Automot Engn Hangzhou 310018 Peoples R China

High-precision injection molded plastic lenses are gradually substituting the application of glass lenses in advanced imaging and illumination optical systems for their high efficiency and reproducibility. Despite the surface deviation of the plastic lenses having been reduced to micron dimension, the imaging performance of the systems could not be guaranteed. More and more investigations demonstrated that the inhomogeneity of refractive index (RI) variation of plastic lenses was much higher than that of glass lenses. However, the effect of refractive index inhomogeneity on imaging performance is still not well understood, and is not fully considered in the optical design and injection molding process. Thus, an integrated analytical approach was proposed to quantitatively evaluate the inhomogeneity of the refractive index and to reveal its effect on the imaging performance of the optical system. It was found that the inhomogeneity reached 3.44 x 10-3, which was three orders of magnitude higher than that of the glass blank (2.80 x 10-6). Both the magnitude and distribution of refractive index variation significantly degraded the quality and homogeneity of the modulation transfer function (MTF) and spot diagram, from calculated imaging performance considering the inhomogeneity. The maximum MTF was reduced by 60 % compared with the design value. Comparative investigation also demonstrated that refractive index inhomogeneity had an equivalent effect on the imaging performance in comparison with the micron order surface deviation. Reducing the degradation of refractive index inhomogeneity provides an efficient way to improve the imaging performance of advanced optical systems.

关键词： Refractive index inhomogeneity Injection molded lens Imaging performance modulation transfer function

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