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Quasi-Continuous Metasurface Beam Splitters Enabled by Vector iterative fourier transform algorithm

MATERIALS 2021年第4期14卷 1022-1022页

作者： Li, Jinzhe Zhang, Fei Pu, Mingbo Guo, Yinghui Li, Xiong Ma, Xiaoliang Wang, Changtao Luo, Xiangang Chinese Acad Sci Inst Opt & Elect State Key Lab Opt Technol Nanofabricat & Microeng POB 350 Chengdu 610209 Peoples R China Univ Chinese Acad Sci Sch Optoelect Beijing 100049 Peoples R China

Quasi-continuous metasurfaces are widely used in various optical systems and their subwavelength structures invalidate traditional design methods based on scalar diffraction theory. Here, a novel vector iterative fourier transform algorithm (IFTA) is proposed to realize the fast design of quasi-continuous metasurface beam splitters with subwavelength structures. Compared with traditional optimization algorithms that either require extensive numerical simulations or lack accuracy, this method has the advantages of accuracy and low computational cost. As proof-of-concept demonstrations, several beam splitters with custom-tailored diffraction patterns and a 7 x 7 beam splitter are numerically demonstrated, among which the maximal diffraction angle reaches 70 degrees and the best uniformity error reaches 0.0195, showing good consistency with the target energy distribution and these results suggest that the proposed vector IFTA may find wide applications in three-dimensional imaging, lidar techniques, machine vision, and so forth.

关键词： quasi-continuous metasurface beam splitter iterative fourier transform algorithm vector diffraction theory

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iterative fourier transform algorithm Based on the Segmentation of Target Image for a High-Speed Binary Spatial Light Modulator

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JOURNAL OF THE OPTICAL SOCIETY OF KOREA 2015年第2期19卷 149-153页

作者： Im, Yeonsu Kim, Hwi Hahn, Joonku Kyungpook Natl Univ Sch Elect Engn Taegu 702701 South Korea Korea Univ Coll Sci & Technol Dept Elect & Informat Engn Sejong 339700 South Korea

A digital micro-mirror device (DMD) has the potential to modulate an incident wave with high speed, and the application for holographic display has been studied by many researchers. However, the quality of reconstructed image isn't good in comparison with that from a gay-scale amplitude-only hologram since it is a binary amplitude-only spatial light modulator (SLM). In this paper, we suggest a method generating a set of binary holograms to improve the quality of the reconstructed image. Here, we are concerned with the case for which the object plane is positioned at the fourier domain of the plane of the SLM. In this case, any point in the fourier plane is related to all points in the hologram. So there is a chance to generate a set of binary holograms illuminated by incident wave with constant optical power. Moreover, we find an interesting fact that the quality of reconstructed image is improved when the spatial frequency bandwidth of the binary hologram is limited. Therefore, we propose an iterative segmentation algorithm generating a set of binary holograms that are designed to be illuminated by the wave with constant optical power. The feasibility of our method is experimentally confirmed with a DMD.

关键词： Digital holography Spatial light modulators iterative fourier transform algorithm

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Generating phase-only diffractive optical elements using adaptive constraints in the fourier domain

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OPTICS COMMUNICATIONS 2023年第1期535卷

作者： Zhou, Xiaoyou Song, Qiang Yang, Xin Cai, Weiwei Shanghai Jiao Tong Univ Sch Mech Engn Key Lab Educ Minist Power Machinery & Engn 800 Dongchuan Rd Shanghai 200240 Peoples R China Lochn Opt Shenzhen Guangdong Peoples R China

In this work, a modified iterative design method of generating pure phase diffractive optical elements is reported. The adaptive constraint on fourier domain was derived as a result of minimizing a criterion -functional. Considering the design for manufacturing, the soft quantization method is introduced into the iteration process. The performance of the proposed algorithm was verified by comparing with the standard iterative design method using a binary as well as gray-scale image. The simulation results demonstrate that the proposed method is superior to the conventional iterative fourier transform algorithm in terms of reconstruction accuracy. The results from proof-of-concept experiments confirmed the conclusions, suggesting that our design method provides a new alternative for the diffractive optics community.

关键词： iterative fourier transform algorithm Diffractive optical element Phase retrieval

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HoloGen: An open-source toolbox for high-speed hologram generation

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COMPUTER PHYSICS COMMUNICATIONS 2022年 270卷 108139-108139页

作者： Christopher, Peter J. Kadis, Andrew Gordon, George S. D. Wilkinson, Timothy D. Univ Cambridge Ctr Mol Mat Photon & Elect Cambridge England Univ Nottingham Dept Elect & Elect Engn Univ Pk Nottingham NG7 2RD England

The rise of virtual and augmented reality systems has prompted an increase in interest in the fields of 2D and 3D computer-generated holography (CGH). The numerical processing required to generate a hologram is high and requires significant domain expertise. This has historically slowed the adoption of CGH in emerging fields. In this paper we introduce HoloGen, an open-source Cuda C and C++ framework for computer-generated holography. HoloGen unites, for the first time, a wide array of existing hologram generation algorithms with state of the art performance while attempting to remain intuitive and easy to use. This is enabled by a C# and Windows Presentation Framework (WPF) graphical user interface (GUI). A novel reflection based parameter hierarchy is used to ensure ease of modification. Extensive use of C++ templates based on the Standard Template Library (STL), compile time flexibility is preserved while maintaining runtime performance. The current release of HoloGen unites implementations of well known generation algorithms including Gerchberg-Saxton (GS), Liu-Taghizadeh (LT), direct search (DS), simulated annealing (SA) and onestep phase-retrieval (OSPR) with less known specialist variants including weighted GS and Adaptive OSPR. Benchmarking results are presented for several key algorithms. The software is freely available under an MIT license. Program summary Program title: HoloGen v2.2.1.17177 CPC Library link to program files: https://doi .org /10 .17632 /nzk4swwsrg .1 Developer's repository link: https://gitlab .com /CMMPEOpenAccess /HoloGen Licensing provisions: MIT Programming language: Cuda, C/C++, C# External packages: Cuda, ManagedCuda, MathNet, ***, NUnit, AForge, Accord, ClosedXML, CefSharp, PdfiumViewer, Xceed, NHotkey, SharpDX, MaterialSkin, ***, HelixToolkit, Dragablz, LiveCharts, MahApps Nature of problem: Hologram generation for two-dimensional fourier and Fresnel holograms displayed on amplitude or phase modulating spati

关键词： Computer-generated holography Optics iterative fourier transform algorithm Gerchberg-Saxton Liu-Taghizadeh Direct search Simulated annealing One-step phase-retrieval

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Three-dimensional beam shaping by means of a spatial phase modulator for two-photon-polymerization

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Procedia CIRP 2022年 111卷 261-265页

作者： Alexander Peter Volkher Onuseit Thomas Graf Institut für Strahlwerkzeuge (IFSW) University of Stuttgart Pfaffenwaldring 43 70569 Stuttgart Germany

Two-photon-polymerization is an additive manufacturing method to produce parts with high resolution. With reachable voxel sizes below the optical diffraction limit, it is of particular interest for biomedical or micro-optical applications. Despite its high resolution, the spreading of this method is hindered by its low productivity in the µm³/s range. Scaling up productivity is in principle possible with already available laser sources with high pulse energy and beam shaping such as multi-spot approaches. This beam shaping is limited in the processable volume and has to be expanded to arbitrary beam shapes in three dimensions to make use of the next generation laser sources with higher pulse energy and higher average laser power. In this work, a three-dimensional iterative fourier transform algorithm for optimizing arbitrary three-dimensional intensity distributions using a spatial phase modulator was investigated for suitability for 2PP.

关键词： three-dimensional beam shaping iterative fourier transform algorithm 2-photon-polymerization spatial light modulator

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Design of Diffractive Optical Elements by Direct and Indirect Construction of Diffraction Pattern: A Comparative Study

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JOURNAL OF ELECTRONIC PACKAGING 2020年第4期142卷 041101页

作者： Xiong, Hui Sun, Liaoxin Hubei Univ Sch Phys & Elect Technol Wuhan 430062 Hubei Peoples R China Chinese Acad Sci Shanghai Inst Tech Phys Shanghai 200083 Peoples R China

In this work, we present the design method of diffractive beam splitters via two comparative technical routes, the first referred as the direct scheme and the second referred as the indirect scheme. Comparative study is carried on the design procedures and results. The advantages of the direct design scheme include overcoming the limit on the number of phase pixels and being capable of realizing beam shaping and splitting simultaneously. Numerical simulation shows that the uniformity of spots array pattern in the direct design is close to that of the indirect design. These results are helpful for the design and application of diffractive optical elements (DOEs) in modern optical devices.

关键词： diffractive optical element beam splitter binary structure iterative fourier transform algorithm integration optics

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Machine learning aided phase retrieval algorithm for beam splitting with an LCoS-SLM 21

Machine learning aided phase retrieval algorithm for beam sp...

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Conference on Laser Resonators, Microresonators, and Beam Control XXI

作者： Mikhaylov, Dmitriy Zhou, Baifan Kiedrowski, Thomas Mikut, Ralf Lasagni, Andres F. Robert Bosch Mfg Solut GmbH Postbox 30 02 20 D-70442 Stuttgart Germany Robert Bosch GmbH Robert Bosch Campus 1 D-71272 Renningen Germany Tech Univ Dresden Inst Mfg Technol George Bahr Str 3c D-01069 Dresden Germany Fraunhofer Inst Werkstoff & Strahlentech IWS Winterbergstr 28 D-01277 Dresden Germany Karlsruhe Inst Technol Inst Automat & Appl Informat IAI Hermann von Helmholtz Pl 1 D-76344 Eggenstein Leopoldshafen Germany

ISBN: (数字)9781510624511

ISBN: (纸本)9781510624511

Liquid crystal on silicon phase-only spatial light modulators are widely used for the generation of multi-spot patterns. The phase distribution in the modulator plane, corresponding to the target multi-spot intensity distribution in the focal plane, is calculated by means of the so-called phase retrieval algorithms. Due to deviations of the real optical setup from the ideal model, these algorithms often do not achieve the desired power distribution accuracy within the multi-spot patterns. In this study, we present a novel method for generating high quality multi-spot patterns even in the presence of optical system disturbances. The standard iterative fourier transform algorithm is extended by means of machine learning methods combined with an open camera feedback loop. The machine learning algorithm is used to predict the mapping function between the desired and the measured multi-spot beam profiles. The problem of generation of mult-ispot patterns is divided into three complexity levels. Due to distinct parameter structures, each of the complexity levels requires differing solution approaches, particularly differing machine learning algorithms. This relation is discussed in detail eventually providing a solution for the simplest case of beam splitter pattern generation. Solutions for more complex problems are also suggested. The approach is validated, whereby one machine learning method is successfully implemented and tested experimentally.

关键词： spatial light modulator iterative fourier transform algorithm beam splitting multi-spot pattern

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Adaptive Laser Beam Shaping for Laser Marking using Spatial light Modulator and Modified iterative fourier transform algorithm

Adaptive Laser Beam Shaping for Laser Marking using Spatial ...

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6th International WLT Conference on Lasers in Manufacturing (LiM)

作者： Beck, Rainer J. Waddie, Andrew J. Parry, Jonathan P. Shephard, Jonathan D. Taghizadeh, Mohammad R. Hand, Duncan P. Heriot Watt Univ Sch Engn & Phys Sci Appl Opt & Photon Grp Edinburgh EH14 4AS Midlothian Scotland Heriot Watt Univ Sch Engn & Phys Sci Diffract Opt Grp Edinburgh EH14 4AS Midlothian Scotland

In this paper we present the application of a modified iterative fourier transform algorithm in combination with a closed loop feedback control using a CCD camera in order to improve the diffraction efficiency and uniformity of two-dimensional intensity distributions generated using a spatial light modulator (SLM). The impact of these improvements is demonstrated for nanosecond laser marking of a two-dimensional data matrix on a thin metal film utilising the dynamic nature of the SLM.

关键词： Spatial light modulator laser micromachining iterative fourier transform algorithm

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Adaptive Laser Beam Shaping for Laser Marking using Spatial light Modulator and Modified iterative fourier transform algorithm

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Physics Procedia 2011年 12卷 465-469页

作者： Rainer J Beck Andrew J Waddie Jonathan P Parry Jonathan D Shephard Mohammad R Taghizadeh Duncan P Hand Applied Optics and Photonics Group School of Engineering and Physical Sciences Heriot-Watt University Edinburgh EH14 4AS UK Diffractive Optics Group School of Engineering and Physical Sciences Heriot-Watt University Edinburgh EH14 4AS UK

关键词： Spatial light modulator laser micromachining iterative fourier transform algorithm

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Engineering an achromatic Bessel beam using a phase-only spatial light modulator and an iterative fourier transformation algorithm

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OPTICS COMMUNICATIONS 2017年 383卷 64-68页

作者： Walde, Marie Jost, Aurelie Wicker, Kai Heintzmann, Rainer Friedrich Schiller Univ Abbe Ctr Photon IPC Jena Germany Corp Res & Technol Carl Zeiss AG Jena Germany Leibniz Inst Photon Technol IPHT Jena Germany

Bessel illumination is an established method in optical imaging and manipulation to achieve an extended depth of field without compromising the lateral resolution. When broadband or multicolour imaging is required, wavelength-dependent changes in the radial profile of the Bessel illumination can complicate further image processing and analysis. We present a solution for engineering a multicolour Bessel beam that is easy to implement and promises to be particularly useful for broadband imaging applications. A phase-only spatial light modulator (SLM) in the image plane and an iterative fourier transformation algorithm (IFTA) are used to create an annular light distribution in the back focal plane of a lens. The 2D fourier transformation of such a light ring yields a Bessel beam with a constant radial profile for different wavelength. (C) 2016 The Authors. Published by Elsevier B.V.

关键词： Bessel beam Spatial light modulator Non-diffracting beams iterative fourier transform algorithm Frequency filtering

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