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Comparative Study of wavefront coding Imaging with Rotational and Non-Rotational Symmetric Phase Masks

Comparative Study of Wavefront Coding Imaging with Rotationa...

5th International Symposium on Photoelectronic Detection and Imaging (ISPDI) - Micro/Nano Optical Imaging Technologies and Applications

作者： Hu, Jiangfei Xu, Feng Zhao, Xiaonan Wang, Chinhua Soochow Univ Educ Minist China Inst Modern Opt Technol Key Lab Adv Opt Mfg Technol Jiangsu Prov Suzhou 215006 Jiangsu Peoples R China Soochow Univ Educ Minist China Key Lab Modern Opt Technol Suzhou 215006 Jiangsu Peoples R China

ISBN: (纸本)9780819497802

wavefront coding enables conventional optical imaging systems to operate over an extended depth of field/focus by modifying the light field using a specially designed phase mask. Different phase masks can be used to alter the transmitted wavefront of the optical system which may result in different performances in terms of the capability of the depth-of-focus extension, aberration suppression and the process of imaging acquirement. In this paper, we present a comparative study on the performances of two major different categories of the phase mask, i.e., rotational symmetric and asymmetric type phase masks. Three different types of phase masks that are of cubic, quartic, and logarithmic phase profile are investigated. Fabrication and metrology of a cubic mask is conducted and a full cycle of imaging process including the image coding and decoding is performed.

关键词： wavefront coding depth of focus rotational symmetric and asymmetric phase mask

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Phase transfer function based method to alleviate image artifacts in wavefront coding imaging system

Phase transfer function based method to alleviate image arti...

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5th International Symposium on Photoelectronic Detection and Imaging (ISPDI) - Infrared Imaging and Applications

作者： Mo Xutao Wang Jinjiang Anhui Univ Technol Inst Image Engn Sch Math & Phys Maanshan 243002 Peoples R China

ISBN: (纸本)9780819497765

wavefront coding technique can extend the depth of filed (DOF) of the incoherent imaging system. Several rectangular separable phase masks (such as cubic type, exponential type, logarithmic type, sinusoidal type, rational type, et al) have been proposed and discussed, because they can extend the DOF up to ten times of the DOF of ordinary imaging system. But according to the research on them, researchers have pointed out that the images are damaged by the artifacts, which usually come from the non-linear phase transfer function (PTF) differences between the PTF used in the image restoration filter and the PTF related to real imaging condition. In order to alleviate the image artifacts in imaging systems with wavefront coding, an optimization model based on the PTF was proposed to make the PTF invariance with the defocus. Thereafter, an image restoration filter based on the average PTF in the designed depth of field was introduced along with the PTF-based optimization. The combination of the optimization and the image restoration proposed can alleviate the artifacts, which was confirmed by the imaging simulation of spoke target. The cubic phase mask (CPM) and exponential phase mask (EPM) were discussed as example.

关键词： wavefront coding phase transfer function phase mask image restoration optimization

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The influence of phase mask position upon wavefront coded system: doublet imaging system 22

The influence of phase mask position upon wavefront coded sy...

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22nd Annual Conference on Novel Optical Systems, Methods, and Applications XXII

作者： Chiu, Po-Sheng Vonmetz, Kurt Canini, Federico Urbach, H. Paul Delft Univ Technol Dept Imaging Phys Lorentzweg 1 NL-2628 CJ Delft Netherlands Datal IP Tech Srl Via San Vitalino 13 I-40012 Calderara Di Reno BO Italy

ISBN: (数字)9781510629042

ISBN: (纸本)9781510629042

Cubic phase wavefront coding technique is applied to an imaging system with the aim of extending the depth of field (DOF). The design is based on the wavefront coding method proposed by Dowski and Cathey(1). The method employs a cubic phase mask (CPM) to modify the point spread function (PSF) of the imaging system under incoherent illumination such that the PSF of the system is formed as an isosceles right triangle, which makes the PSF insensitive to defocus. Researchers have found the optimized values of cubic phase coefficient and the exit pupil distance for the given specifications for solving wavefront coded task-based imaging problem(2). The extended DOF design is usually based on placing a phase mask exactly in the pupil plane of the imaging system. However, this is not always practical because the complex design of the imaging system leads to a limited practical advantage of this kind of arrangement. In this work, the influence of phase mask position upon wavefront coding technique in the doublet imaging system is studied. The main goal is to find the position where to place the CPM in the imaging system, which type of arrangement can effectively improve the modulation transfer function. Finally, we compare two system configurations, front aperture stop and rear aperture stop in designing the doublet wavefront coded system.

关键词： wavefront coding cubic phase mask task-based imaging

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Microscope with extension of the depth of field by employing a cubic phase plate on the surface of lens

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RESULTS IN OPTICS 2021年 4卷

作者： Lee, Chi-Feng Lee, Cheng-Chung Natl Cent Univ Dept Opt & Photon 300 ChungDa Rd Chungli Taoyuan 32001 Taiwan

An incoherent optical system with wavefront coding extends the depth of field (DOF) by employing a cubic phase plate (CPP). We designed a digital microscope with a CPP in the aperture stop and on the surface of the lens, which extended the DOF. In addition, we proposed a method in which the CPP can be shifted and assigned to the surface of the lens by adjusting the third-order coefficient of the xy polynomial surface, so that the CPP on the surface of the lens can replace a single CPP in the aperture stop, which collided with the optical elements and mechanism in some cases, to reduce the difficulty in assembling. The microscope with flexibility and without loss of the illumination level can considerably improve the efficiency of microscopic applications.

关键词： Extended depth of field Cubic phase plate Optical design wavefront coding

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wavefront coded light-field imaging system to achieve substantial retroreflection reduction and anti-laser blinding property

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OPTIK 2019年 192卷 162947-000页

作者： Wang, Lei Dou, Xianan Ye, Qing Nie, Jinsong Sun, Xiaoquan State Key Lab Pulsed Power Laser Technol China 460 Huangshan Rd Hefei 230037 Anhui Peoples R China

To achieve a substantial retroreflection reduction accompanied with a superior anti-laser blinding property without suffering significant degradations in imaging quality, we design a novel imaging system based on the wavefront coded light-field rendering. Relevant studies have been carried out around its mechanism in both anti-laser reconnaissance and blinding. According to the Fresnel-Kirchhoff diffraction theory, the laser propagation through the composite imaging system is theoretically modeled. By comparison among the conventional, the wavefront coding, the light-field, and the composite imaging systems with different defocus parameters and phase modulation coefficients, the spot profiles and intensity distributions on both the imaging and observation planes are further studied, according to which the optimization principle is proposed. The results show that compared with the conventional one, the composite imaging system could not only increase the interference and blinding thresholds by nearly one order of magnitude but also attenuate the retroreflection peak intensity and the echo-detector receiving power by even more than one order of magnitude, achieving the superior properties of anti-laser reconnaissance and blinding.

关键词： Imaging system Retroreflection reduction wavefront coding Light-field imaging Laser interference and blinding

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Optical transfer function analysis of circular-pupil wavefront coding systems with separable phase masks

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Chinese Physics B 2012年第6期21卷 200-206页

作者：赵廷玉刘钦晓余飞鸿 Department of Physics Zhejiang Sci-Tech University Optical Engineering Department Zhejiang University

This paper proposes a simple method to achieve the optical transfer function of a circular pupil wavefront coding system with a separable phase mask in Cartesian coordinates. Based on the stationary phase method, the optical transfer function of the circular pupil system can be easily obtained from the optical transfer function of the rectangular pupil system by modifying the cut-off frequency and the on-axial modulation transfer function. Finally, a system with a cubic phase mask is used as an example to illustrate the way to achieve the optical transfer function of the circular pupil system from the rectangular pupil system.

关键词： wavefront coding circular pupil separable phase mask stationary phase method

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Implementation of a wavefront coded microscope by the use of a spatial light modulator 19

Implementation of a Wavefront coded microscope by the use of...

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19th Conference on Current Developments in Lens Design and Optical Engineering

作者： Ortega-Sanchez, K. Toxqui-Quitl, C. Padilla-Vivanco, A. Univ Politecn Tulancingo Ingn 100 Tulancingo 43629 Hidalgo Mexico

ISBN: (数字)9781510620629

ISBN: (纸本)9781510620629

wavefront coding (WFC) technique is typically used to compensate for optical aberrations related to defocus. An advantage of WFC are that the depth of field (DOF) will be increased and the weight and size of an optical system are reduced. In this work a WFC system is analyzed to extend the DOF of the microscope objective. The Point Spread Function (PSF) is used to modify in such a way that it is invariant to defocus in a range of axial distances. A liquid crystal display light modulator (LC SLM) in a 4f imaging system is used for the implementation of the phase masks (PM). LC SLM screens modulate both the amplitude and the phase of the input beam. This display allows a flexible implementation of different profiles of phase masks that are generated from different families of functions, this is because the parameters can be dynamically modified. In this document, we propose an experimental setup for extended DOF in optical microscopy. Experimental results are presented using a LC - SLM.

关键词： wavefront coding Phase Mask Microscope system LC-SLM

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Experimental validation of hybrid optical-digital imaging system for extended depth-of-field based on co-optimized binary phase masks

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OPTICAL ENGINEERING 2019年第11期58卷 113107-113107页

作者： Fontbonne, Alice Sauer, Herve Kulcsar, Caroline Coutrot, Anne-Lise Goudail, Francois Univ Paris Saclay CNRS Inst Opt Grad SchLab Charles Fabry Palaiseau France

We experimentally investigate the performance of co-optimized hybrid optical-digital imaging systems based on binary phase masks and digital deconvolution for extended depth-of-field (DoF) under narrowband illumination hypothesis. These systems are numerically optimized by assuming a simple generic imaging model. Using images of DoF targets and real scenes, we experimentally demonstrate that in practice, they actually reach the DoF range for which they have been optimized. Moreover, they are shown to be robust against small mask manufacturing errors and residual spherical aberration in the optical system. These results demonstrate that the optical/digital optimization protocol based on generic imaging model can be safely used to design DoF-enhanced imaging systems aimed at real-world applications. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： image processing binary phase masks deconvolution optical system codesign wavefront coding experimental validation

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Optimized Asymmetrical Arcsine Phase Mask for Extending the Depth of Field

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IEEE PHOTONICS TECHNOLOGY LETTERS 2018年第14期30卷 1309-1312页

作者： Wang, Lei Ye, Qing Nie, Jinsong Sun, Xiaoquan Natl Univ Def Technol State Key Lab Pulsed Power Laser Technol Hefei 230037 Anhui Peoples R China

With the development of wavefront coding technique, various x-y separable phase masks have been proposed for the purpose of extending the depth of field. In this letter, a new asymmetrical arcsine phase mask combing the power and arcsine function was proposed to enrich the separable odd symmetrical family of wavefront coding phase masks. Using the simulated annealing algorithm based on Fisher information for optimization, we evaluated the performance of arcsine phase mask with four typical phase masks: the tangent, sinusoidal, improved-2 logarithmic, and cubic phase masks. The comparison results of Fisher information, defocused modulation transfer function, Hilbert space angle, and digital restoration demonstrated that the arcsine phase mask could restore clear and homogeneous images with both high fidelity and high signal to noise ratio along with a wide range of defocus, proving its superiority in extending the depth of field.

关键词： Image restoration optical imaging phase modulation wavefront coding

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Design and implementation of a scene-dependent dynamically selfadaptable wavefront coding imaging system

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COMPUTER PHYSICS COMMUNICATIONS 2012年第1期183卷 147-154页

作者： Carles, Guillem Ferran, Carme Carnicer, Artur Bosch, Salvador Univ Barcelona Dept Fis Aplicada & Opt E-08028 Barcelona Spain

A computational imaging system based on wavefront coding is presented. wavefront coding provides an extension of the depth-of-field at the expense of a slight reduction of image quality. This trade-off results from the amount of coding used. By using spatial light modulators, a flexible coding is achieved which permits it to be increased or decreased as needed. In this paper a computational method is proposed for evaluating the output of a wavefront coding imaging system equipped with a spatial light modulator, with the aim of thus making it possible to implement the most suitable coding strength for a given scene. This is achieved in an unsupervised manner, thus the whole system acts as a dynamically selfadaptable imaging system. The program presented here controls the spatial light modulator and the camera, and also processes the images in a synchronised way in order to implement the dynamic system in real time. A prototype of the system was implemented in the laboratory and illustrative examples of the performance are reported in this paper. Program summary Program title: DynWFC (Dynamic wavefront coding) Catalogue identifier: AEKC_v1_0 Program summary URL: http://***/summaries/AEKC_v1_*** Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://***/licence/*** No. of lines in distributed program, including test data, etc.: 10 483 No. of bytes in distributed program, including test data, etc.: 2 437 713 Distribution format: *** Programming language: Labview 8.5 and NI Vision and MinGW C Compiler Computer: Tested on PC Intel (R) Pentium (R) Operating system: Tested on Windows XP Classification: 18 Nature of problem: The program implements an enhanced wavefront coding imaging system able to adapt the degree of coding to the requirements of a specific scene. The program controls the acquisition by a camera, the display of a spatial light modulator

关键词： Imaging systems Image processing wavefront coding Selfadaptable coding strength

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