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Through-focus performance and off-axis effects in aspheric monofocal intraocular lenses

BIOMEDICAL OPTICS EXPRESS 2024年第10期15卷 6073-6082页

作者： Labuz, Grzegorz Yan, Weijia Khoramnia, Ramin Auffarth, Gerd U. Univ Hosp Heidelberg David J Apple Ctr Vis Res Dept Ophthalmol INF 400 D-69120 Heidelberg Germany Zhejiang Univ Affiliated Hosp 2 Eye Ctr Sch Med Hangzhou 310009 Peoples R China

This study aimed to determine the through-focus performance and the effect of misalignment on the optical quality of different aspheric monofocal intraocular lenses (IOLs). To this end, optical quality was assessed in three IOL models with different optic surfaces: standard aberration neutral model and two spherical aberration (SA) correcting, one of which utilizes higher-order aspheric terms. The optical quality was measured by means of the modulation transfer function at 3- and 4.5-mm pupils and under monochromatic and polychromatic light with different corneal SA. The optically derived range of vision and tolerance to misalignment were also tested. The study demonstrated that the type of IOL surface affects the monofocal implant's performance. Although a standard primary-SA correction may improve scotopic image quality, misalignment may diminish this advantage. The higher-order aspheric surface used to correct SA provided an improved performance against decentration and offered a higher optical quality than the aberration-neutral design when tested in a model eye. The latter, however, demonstrated a high tolerance to misalignment, offering a slight extension of the range of vision, potentially resulting from uncorrected optical aberrations. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： Eye models Image quality LED sources modulation transfer function Optical aberration Spherical aberration

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Infrared Optical System for Long-range Forward Imaging on Airborne Platforms

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CURRENT OPTICS AND PHOTONICS 2024年第6期8卷 575-584页

作者： Park, Kwang-Woo Kong, Hyunbae Kim, Junghwan Choi, Siyoun Agcy Def Dev Daejeon 34060 South Korea LIG Nex1 Co Ltd Yongin 16911 South Korea

This study presents the design, assembly, and evaluation of an airborne platform camera with mid-infrared wavelengths for long-range observations in the forward direction. Considering the limited mounting space and two-axis drive range (pitch: -40 degrees to 40 degrees, yaw: -10 degrees to 10 degrees), we designed an optical system with optimized space constraints using mirrors and a structure in which the entire lens system is driven. The resulting focal length was 183 mm, the field-of-view (FOV) was 1.2 degrees x 1.2 degrees, and the modulation transfer function (MTF) value was 36.3%. Consqeuntly, a system with an FOV of 1.2 degrees+0.03 and an MTF value of more than 10% was manufactured. We proposed an optimal assembly method to meet these requirements. The performance of the fabricated optical system with an FOV of 1.200 degrees x 1.200 degrees and an MTF of 12.7% was measured. The validity of the proposed approach was verified by presenting reliable manufacturing results that correspond to the design specifications.

关键词： Airborne camera IR camera Lens design modulation transfer function Two-axis gimbal

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Cooling film's suppressive effects on infrared system's radiation noise in aero-thermal environment

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OPTICS EXPRESS 2024年第22期32卷 38819-38835页

作者： Wang, Shushen Ding, Hao Tian, Lifeng Sun Yat Sen Univ Sch Aeronaut & Astronaut Shenzhen Campus Shenzhen 518107 Peoples R China Sun Yat Sen Univ Shenzhen Key Lab Intelligent Microsatellite Conste Shenzhen Campus Shenzhen 518107 Peoples R China

Infrared imaging systems are crucial for guidance in supersonic vehicles due to all-weather capability, high resolution and high sensitivity. However, the imaging quality can be significantly impaired by aerodynamic thermal radiation noise. This paper incorporates cooling film that effectively eliminates the interference originating from supersonic thermal environments. A radiative transfer calculation framework that utilizes a high resolution line-by-line method for precise computation of radiative transfer from the target to the sensors of the imaging system is proposed. Heat flux across individual pixels indicates that the optical window serves as the primary source of interference within the 3 to 5 mu m range. Additionally, the implementation of a cooling film significantly diminishes radiation noise, reducing interferences originating from both the optical window and the shock layer by an order of magnitude. Spectral analysis of the pixel's heat flux underscores the pivotal roles of CO2 and H2O in the absorption and emission processes within radiative transfer, thereby complicating the observations of remote sensing. Contrasting with the traditional spectral band model, our methodology affords wavelength-specific visualization of radiative intensities for both target and interference signals. This enhanced spectral resolution provides a foundational reference for significant enhancements in both the clarity and accuracy of the imaging system. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： Image sensors Imaging systems Infrared imaging Infrared sensors modulation transfer function Remote sensing

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Influence of grid guard diodes with floating n-region potential on the spatial resolution of n-on-p linear HgCdTe photodetectors

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JOURNAL OF OPTICAL TECHNOLOGY 2024年第2期91卷 100-104页

作者： Vasiliev, Vladimir V. Vishnyakov, Aleksey V. Sabinina, Irina B. Sidorov, Georgiy Yu. Stuchinsky, Victor A. Russian Acad Sci Rzhanov Inst Semicond Phys Siberian Branch Novosibirsk Russia

Subject of study. The focus of this study is the spatial resolution of n-on- p linear focal-plane-array detectors based on mercury-cadmium-telluride material and modified by introducing into their structure a grid guard diode with floating n-region potential. The aims of the study are to perform an analysis of the influence of a grid guard diode with floating n-region potential on the line spread and modulation transfer functions of the linear n-on-p p photodetectors. Moreover, the possibility of using structural defects in the examined photodetectors is investigated for implementing a continuous action of the guard diode as a sink for photogenerated charge carriers. Method. . The diffusion of photogenerated charge carriers in the absorber layer of focal-plane-array detectors is modeled using the Monte Carlo method. Furthermore, the spatial resolution of such photodetectors is experimentally investigated by performing spot-scan measurements and calculating the modulation transfer function of photodetector structures. Main results. . The presence of the grid diode with floating n-region potential in the structure of n-on- p photodetectors broadens the base and decreases the width of the upper part of the line-spread-function peak of linear focal plane arrays with the corresponding modification of the modulation transfer function. However, overall, no significant improvement is observed in the resolution of the modified photodetector structure. Practical significance. . The results of this study indicate that the guard diodes in the photodetectors must be grounded. These results can also be used in the development of methods for optimizing and enhancing the spatial resolution of focal-plane-array detectors. (c) 2024 Optica Publishing Group

关键词： Detectors modulation transfer function Photodetectors Physical vapor deposition Resolution Spatial resolution

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Quantifying natural higher order aberration(s) in emmetropic human eyes and objectively evaluating retinal image quality

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OPHTHALMIC AND PHYSIOLOGICAL OPTICS 2025年第3期45卷 769-778页

作者： Gupta, Vinay Bari, Aafreen Anjum, Shahnaz Yadav, Ankit Saxena, Rohit Sinha, Rajesh All India Inst Med Sci Dr RP Ctr Ophthalm Sci New Delhi India

AimThis study aimed to quantify the internal, corneal and total higher order aberrations (HOAs) in the healthy human eye using ray tracing technology in bright and dim light conditions. The study also aimed to evaluate the retinal image quality and contrast modulation at different spatial frequencies, objectively using image-quality metrics derived from wavefront *** cross-sectional prospective observational study was conducted on 521 emmetropic young adults. HOAs including coma, trefoil, spherical aberration and secondary astigmatism were measured separately for the cornea, internal and total eye using a ray-tracing wavefront aberrometer at mesopic and photopic pupil sizes. The Strehl ratio, derived from the point spread function (PSF), was used to evaluate the retinal image quality of the eye. Contrast modulation at spatial frequencies of 5, 10 and 15 cycles per degree was assessed through the modulation transfer function (MTF).ResultsMean age of participants was 25.4 +/- 4.8 years (54.5% male). The total HOAs of internal, corneal and total eye were 0.186 +/- 0.075, 0.191 +/- 0.112 and 0.222 +/- 0.075 mu, respectively for a 5-mm pupil (dim light condition), and 0.069 +/- 0.031, 0.061 +/- 0.094 and 0.076 +/- 0.031 mu, respectively, for a 3-mm pupil (bright light condition). The Strehl ratio was 0.16 +/- 0.124 (5 mm pupil) and 0.601 +/- 0.19 (3 mm pupil). A normative database was created and correlations drawn for the HOAs, PSF and MTF (using image quality metrics) for the cornea, internal and total eye at mesopic and photopic pupil *** findings provide normal population (young healthy adults) reference ranges for HOAs, retinal image quality and contrast modulation at higher spatial frequencies using ray tracing technology. The presence of these natural wavefront aberrations enhances the visual performance and may not need to be corrected. The separate assessment of aberrations and derived image quality metrics for the cornea,

关键词： higher order aberrations i-Tracey modulation transfer function ocular aberrations point spread function wavefront aberrometry.

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An improved blind/referenceless image spatial quality evaluator algorithm for image quality assessment

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INTERNATIONAL JOURNAL OF COMPUTATIONAL SCIENCE AND ENGINEERING 2024年第1期27卷 48-56页

作者： Li, Xuesong Pan, Jinfeng Shang, Jianrun Souri, Alireza Gao, Mingliang Shandong Univ Technol Sch Elect & Elect Engn Zibo Shandong Peoples R China Halic Univ Dept Comp Engn Istanbul Turkiye

Image quality assessment (IQA) methods are generally studied in the spatial or transform domain. Due to the BRISQUE algorithm evaluating the quality of an image only based on its natural scene statistics of the spatial domain, the frequency features that are extracted from the modulation transfer function (MTF) are applied to improve its performance. MTF is estimated based on the slanted-edge method. The two-dimensional grey fitting algorithm is utilised to estimate the edge slope more accurately. Then the three-order Fermi function is utilised to match the preliminary estimated edge spread function to reduce the aliasing influence on MTF estimation. The features such as crucial frequency and the MTF value at Nyquist frequency are calculated and adopted to the BRISQUE method to assess the image quality. Experimental results on the image quality assessment databases illustrated that the proposed method outperforms the BRISQUE method and some other common methods, based on the linear and nonlinear correlation between the image quality assessed by the methods and their subjective value.

关键词： image quality assessment IQA modulation transfer function MTF Fermi function feature extraction

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Differential phase contrast intensity diffraction tomography

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OPTICS LETTERS 2024年第23期49卷 6861-6864页

作者： Bai, Zhidong Zhou, Shun Ullah, Habib Lu, Linpeng Chen, Qian Zuo, Chao Nanjing Univ Sci & Technol Sch Elect & Opt Engn Smart Computat Imaging Lab SCILab Nanjing 210094 Jiangsu Peoples R China Nanjing Univ Sci & Technol Smart Computat Imaging Res Inst SCIRI Nanjing 210019 Jiangsu Peoples R China Jiangsu Key Lab Spectral Imaging & Intelligent Sen Nanjing 210094 Jiangsu Peoples R China

Intensity diffraction tomography (IDT) is a label-free computational microscopy technique that infers 3D refractive index (RI) and absorption distributions of objects from intensity-only measurements. Nevertheless, the inherent coherent image formation model requires sequential intensity measurements under various plane wave illuminations, resulting in time-consuming data acquisition and low imaging speed. In this Letter, we propose differential phase contrast intensity diffraction tomography (DPC-IDT), which leverages partially coherent illumination to extend the accessible spectrum range, thereby achieving highspeed, motion-free 3D tomographic microscopy. DPC-IDT integrates DPC illumination within the IDT framework, allowing 3D RI tomogram reconstruction from only four intensity images under matched asymmetric annular illumination. The effectiveness of DPC-IDT is experimentally validated by RI measurements of standard microspheres. We also demonstrate dynamic 3D imaging results of living PLC cells at a 25 Hz volume rate, highlighting its potential for high-speed biological imaging of unstained samples. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

关键词： Biomedical imaging Imaging systems modulation transfer function Optical transfer functions Phase contrast Three dimensional microscopy

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Psychophysics of neon color spreading: Chromatic and temporal factors are not limiting

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VISION RESEARCH 2024年 223卷 108460页

作者： He, Jingyi Mingolla, Ennio Eskew Jr, Rhea T. Northeastern Univ Coll Sci Dept Psychol Boston MA 02115 USA Northeastern Univ Bouve Coll Hlth Sci Commun Sci & Disorders Boston MA USA

Neon color spreading (NCS) is an illusory color phenomenon that provides a dramatic example of surface completion and filling-in. Numerous studies have varied both spatial and temporal aspects of the neongenerating stimulus to explore variations in the strength of the effect. Here, we take a novel, parametric, lowlevel psychophysical approach to studying NCS in two experiments. In Experiment 1, we test the ability of both cone-isolating and equiluminant stimuli to generate neon color spreading for both increments and decrements in cone modulations. As expected, sensitivity was low to S(hort-wavelength) cone stimuli due to their poor spatial resolution, but sensitivity was similar for the other color directions. We show that when these differences in detection sensitivity are accounted for, the particular cone type, and the polarity (increment or decrement), make little difference in generating neon color spreading, with NCS visible at about twice detection threshold level in all cases. In Experiment 2, we use L-cone flicker modulations (reddish and greenish excursions around grey) to study sensitivity to NCS as a function of temporal frequency from 0.5 to 8 Hz. After accounting for detectability, the temporal contrast sensitivity functions for NCS are approximately constant or even increase over the studied frequency range. Therefore there is no evidence in this study that the processes underlying NCS are slower than the low-level processes of simple flicker detection. These results point to relatively fast mechanisms, not slow diffusion processes, as the substrate for NCS.

关键词： Neon color spreading Color filling-in modulation transfer function Contrast sensitivity function

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Vibration disturbance compensation in in situ confocal microscopy

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OPTICS LETTERS 2024年第19期49卷 5567-5570页

作者： Liu, Jian Xu, Zhenlong Wang, Ziyi Liu, Chenguang Harbin Inst Technol Sch Instrumentat Sci & Engn Harbin 150001 Peoples R China

In situ microscopic measurement, conducted within the natural environment of a material or device, offers precise observations directly at the sample location, mitigating potential damage or deformation during transport. However, the inherent vibration of microscopic measurement equipment can introduce blurring and distortion to images, compromising measurement accuracy. This study proposes employing an acceleration sensor to detect microprobe vibrations and subsequently calculates three-dimensional coordinate displacements to compensate for measurement discrepancies. This approach can diminish the adverse effects of vibration on measurement outcomes within the order of hundreds of nanometers. Experimental results demonstrated the efficacy of this method in mitigating vibration artifact stripes or irregularities with a displacement amplitude I = sinc2[a(z - b)] ranging from similar to 0.2 to 5.2 mu m and a frequency spanning similar to 7.9-18.8 Hz. Moreover, the lateral resolution of the probe attained 212 nm. Notably, the measurement error associated with the standard step height was decreased from 2.32 to 0.03 mu m. (c) 2024 Optica Publishing Intelligence (AI) training, and similar technologies, are reserved.

关键词： Bandpass filters Charge-coupled devices Image metrics modulation transfer function Optical components Speckle patterns

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Analysis of the optical performance of intraocular lenses using profilometric measurements

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GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY 2025年第2期263卷 451-465页

作者： Miret, Juan J. Camps, Vicente J. Garcia, Celia Caballero, Maria T. Gonzalez-Leal, Juan M. Univ Alicante Dept Opt Pharmacol & Anat Grp Opt & Visual Percept San Vicente Del Raspeig Alicante Spain Univ Cadiz Fac Sci Dept Condensed Matter Phys Cadiz Spain

Purpose The aim of this study was to develop a methodology, based on profilometer measurements to assess the optical behaviour of Intraocular Lenses (IOls). The "modulation transfer function through-object" (MTF through-object) based on vergence object displacement was calculated for different pupil sizes and pseudophakic eyes. Tilt and decentration were also analysed in a realistic cornea eye model. Methods For comparison between the different IOLs, an optical quality criterion based on a minimum value the MTF through-object and the recognition of simulated vision optotypes was introduced. Five IOLs were used in this study: Tecnis Eyhance, Mini Well, Tecnis Symfony, Tecnis Synergy and RayOne EMV. Results The technique was validated with previous methodologies. A general narrowing of the through-object MTF curve compared to the through-focus MTF curve was shown, resulting in greater distances between near and intermediate points and less depth of field around the far peak. The comparison between the IOLs showed that variations in corneal aberrations, pupil size and decentration caused relevant changes in IOL performance. A decrease of the SA produced a hypermetropic shift of the far focus between + 0.3 D and + 0.4 D. Most of IOLs worsen the optical quality as pupil size increased, even the MTF through-object shape changed. Decentration was an important factor in IOL implantation, causing a significant change in MTF through-object shape in most of IOLs. Conclusions This study highlights the need to evaluate pre-operative patients for corneal aberrations and pupillary size to have the best optical success after cataract surgery in multifocal or extended depth of focus IOLs.

关键词： Optical quality Multifocal Intraocular lenses Extended Depth of Focus Pupil size modulation transfer function Decentration Tilt

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