Matthew L. Hall, K. Gleave, Angela Hughes, P. McCall, C. Towers, D. Towers
Understanding mosquito interaction with long-lasting insecticidal bednets is crucial in the development of more effective intervention methods to protect humans from malaria transmission. As such, a 240 × 240 × 1000 mm laboratory setup for the in-line recording of digital holograms and subsequent in-focus reconstruction and 3D localisation of mosquitoes is presented. Simple bednet background removal methods are used to accurately localise a mosquito obscured by a bednet in 3D coordinates. Simulations and physical data demonstrate that this method is suitable for mosquitoes positioned 3-1000 mm behind a bednet. A novel post-processing technique, involving a cascade-correlation of a Tamura of Intensity focus metric extracted from digitally reconstructed scenes, accurately localises mosquitoes positioned 35-100 mm behind a bednet from a single digital hologram. The result of this study is a scalable digital holographic methodology to examine mosquito-bednet interaction in 3D at a level of accuracy previously only seen in 2D imaging of mosquitoes in a much smaller volume.
{"title":"The application of digital holography for accurate three-dimensional localisation of mosquito-bednet interaction","authors":"Matthew L. Hall, K. Gleave, Angela Hughes, P. McCall, C. Towers, D. Towers","doi":"10.37188/lam.2022.020","DOIUrl":"https://doi.org/10.37188/lam.2022.020","url":null,"abstract":"Understanding mosquito interaction with long-lasting insecticidal bednets is crucial in the development of more effective intervention methods to protect humans from malaria transmission. As such, a 240 × 240 × 1000 mm laboratory setup for the in-line recording of digital holograms and subsequent in-focus reconstruction and 3D localisation of mosquitoes is presented. Simple bednet background removal methods are used to accurately localise a mosquito obscured by a bednet in 3D coordinates. Simulations and physical data demonstrate that this method is suitable for mosquitoes positioned 3-1000 mm behind a bednet. A novel post-processing technique, involving a cascade-correlation of a Tamura of Intensity focus metric extracted from digitally reconstructed scenes, accurately localises mosquitoes positioned 35-100 mm behind a bednet from a single digital hologram. The result of this study is a scalable digital holographic methodology to examine mosquito-bednet interaction in 3D at a level of accuracy previously only seen in 2D imaging of mosquitoes in a much smaller volume.","PeriodicalId":56519,"journal":{"name":"光:先进制造(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69983751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Petrov, B. Sokolenko, M. Kulya, Andrei Gorodetsky, A. Chernykh
Design of broadband terahertz vector and vortex beams: I. Review of materials and Components. Light: Abstract In this paper, we review the existing approaches for vortex and vector beam shaping and generation in the terahertz frequency range. The particular focus of this review is on the possibility of homogeneous topological charge formation in the ultra-wide spectral interval inherent to ultrashort terahertz pulses. We review the available materials and components, analyse proposed and potentially possible solutions for broadband terahertz vortex and vector beam shaping, compare all developed approaches, and put forward a unified concept for constructing passive shapers of such beams from the existing component base.
{"title":"Design of broadband terahertz vector and vortex beams: I. Review of materials and components","authors":"N. Petrov, B. Sokolenko, M. Kulya, Andrei Gorodetsky, A. Chernykh","doi":"10.37188/lam.2022.043","DOIUrl":"https://doi.org/10.37188/lam.2022.043","url":null,"abstract":"Design of broadband terahertz vector and vortex beams: I. Review of materials and Components. Light: Abstract In this paper, we review the existing approaches for vortex and vector beam shaping and generation in the terahertz frequency range. The particular focus of this review is on the possibility of homogeneous topological charge formation in the ultra-wide spectral interval inherent to ultrashort terahertz pulses. We review the available materials and components, analyse proposed and potentially possible solutions for broadband terahertz vortex and vector beam shaping, compare all developed approaches, and put forward a unified concept for constructing passive shapers of such beams from the existing component base.","PeriodicalId":56519,"journal":{"name":"光:先进制造(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69983931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface plasmon devices mounted at the end-facets of optical fibers are appealing candidates for rapid and pointof-care sensing applications, by offering a special dip-and-read operation mode. At present, these devices’ noiseequivalent limits-of-detection lag far behind the free-space counterparts, leaving them incapable of most biosensing applications. Here we report a quasi-3D Fano resonance cavity and its fabrication method to fundamentally improve the quality factor and coupling efficiency for fiber-coupled surface plasmon resonance. In this device, the Fano resonance combines the high coupling efficiency of a Fabry-Pérot etalon and the high quality factor resonance of a plasmonic crystal cavity. The quasi-3D device was fabricated on a planar substrate and transferred to a single-mode fiber end-facet, which requires a low-adhesion yet surface-plasmon-tunneling interface between the device and the planar substrate. Such an interface was realized with a nanocap-slit unit structure, of which the plasmonic crystal was consisted. A noise-equivalent limit of detection of ~ 10 RIU was experimentally obtained, allowing bovine serum albumin physical adsorption to be distinguished at ng mL level concentrations. Therefore, breaking through the long-standing signal-to-noise ratio bottleneck, this work makes fiber end-facet surface plasmon devices into one of high sensitivity label-free sensing technologies. At the same time, it provides an enabling top-down fabrication technology for making 3D plasmonic structures on fiber endfacets at the nanometer scale.
{"title":"A quasi-3D fano resonance cavity on optical fiber end-facet for high signal-to-noise ratio dip-and-read surface plasmon sensing","authors":"Xiaqing Sun, Zeyu Lei, Hao Zhong, Chenjia He, Sihang Liu, Qingfeng Meng, Qingwei Liu, Shengfu Chen, Xiangyang Kong, Tian Yang","doi":"10.37188/lam.2022.046","DOIUrl":"https://doi.org/10.37188/lam.2022.046","url":null,"abstract":"Surface plasmon devices mounted at the end-facets of optical fibers are appealing candidates for rapid and pointof-care sensing applications, by offering a special dip-and-read operation mode. At present, these devices’ noiseequivalent limits-of-detection lag far behind the free-space counterparts, leaving them incapable of most biosensing applications. Here we report a quasi-3D Fano resonance cavity and its fabrication method to fundamentally improve the quality factor and coupling efficiency for fiber-coupled surface plasmon resonance. In this device, the Fano resonance combines the high coupling efficiency of a Fabry-Pérot etalon and the high quality factor resonance of a plasmonic crystal cavity. The quasi-3D device was fabricated on a planar substrate and transferred to a single-mode fiber end-facet, which requires a low-adhesion yet surface-plasmon-tunneling interface between the device and the planar substrate. Such an interface was realized with a nanocap-slit unit structure, of which the plasmonic crystal was consisted. A noise-equivalent limit of detection of ~ 10 RIU was experimentally obtained, allowing bovine serum albumin physical adsorption to be distinguished at ng mL level concentrations. Therefore, breaking through the long-standing signal-to-noise ratio bottleneck, this work makes fiber end-facet surface plasmon devices into one of high sensitivity label-free sensing technologies. At the same time, it provides an enabling top-down fabrication technology for making 3D plasmonic structures on fiber endfacets at the nanometer scale.","PeriodicalId":56519,"journal":{"name":"光:先进制造(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69983958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhe Wang, L. Miccio, S. Coppola, V. Bianco, P. Memmolo, V. Tkachenko, V. Ferraro, E. Maio, P. Maffettone, P. Ferraro
The appearance of the first laser approximately 12 years after the invention of holography by Gabor (1948) revolutionized the field of optical metrology. In fact, the invention of holographic interferometry enabled the exploitation of interferometry on non-mirror surfaces and full-scale objects. The holography-based measurement methods has been implemented to several industrial systems or in support of R&D with the aim of improving new products in many fields (automotive, aerospace, electronics, etc.). To date, holography has been considered an important measurement tool for non-destructive inspection (NDI), strain-stress measurement, and vibration analysis at various engineering sites. Recently, the new paradigm of Industry4.0 has seen the introduction of new technologies and methods of processing materials as well as the development of manufacturing approaches for the realization of innovative products. For example, direct printing, additive, and bottom-up manufacturing processes are expected to involve new ways of making products in future, and most innovative fabrication processes will be based on the manipulation of soft matter (e.g., starting from the liquid phase) that will be shaped at the nanoscale. The inherent characteristics of digital holography (DH) make it a powerful and accurate tool for the visualization and testing of final products, as well as for in situ and real-time monitoring and quantitative characterization of the processes involved during the fabrication cycle. This review aims to report on the most useful applications of soft matter, where the capabilities offered by DH, such as three-dimensional (3D) imaging, extended focus, 3D tracking, full-field analysis, high sensitivity, and a wide range of measurements from nanometers to centimeters, permit completely non-invasive characterizations on a full-scale. Several holographic experimental results of typical samples are reported and discussed where DH plays a primary role as a tool gauge for soft matter. ACCEPTED ARTICLE PREVIEW
{"title":"Digital holography as metrology tool at micro-nanoscale for soft matter","authors":"Zhe Wang, L. Miccio, S. Coppola, V. Bianco, P. Memmolo, V. Tkachenko, V. Ferraro, E. Maio, P. Maffettone, P. Ferraro","doi":"10.37188/lam.2022.010","DOIUrl":"https://doi.org/10.37188/lam.2022.010","url":null,"abstract":"The appearance of the first laser approximately 12 years after the invention of holography by Gabor (1948) revolutionized the field of optical metrology. In fact, the invention of holographic interferometry enabled the exploitation of interferometry on non-mirror surfaces and full-scale objects. The holography-based measurement methods has been implemented to several industrial systems or in support of R&D with the aim of improving new products in many fields (automotive, aerospace, electronics, etc.). To date, holography has been considered an important measurement tool for non-destructive inspection (NDI), strain-stress measurement, and vibration analysis at various engineering sites. Recently, the new paradigm of Industry4.0 has seen the introduction of new technologies and methods of processing materials as well as the development of manufacturing approaches for the realization of innovative products. For example, direct printing, additive, and bottom-up manufacturing processes are expected to involve new ways of making products in future, and most innovative fabrication processes will be based on the manipulation of soft matter (e.g., starting from the liquid phase) that will be shaped at the nanoscale. The inherent characteristics of digital holography (DH) make it a powerful and accurate tool for the visualization and testing of final products, as well as for in situ and real-time monitoring and quantitative characterization of the processes involved during the fabrication cycle. This review aims to report on the most useful applications of soft matter, where the capabilities offered by DH, such as three-dimensional (3D) imaging, extended focus, 3D tracking, full-field analysis, high sensitivity, and a wide range of measurements from nanometers to centimeters, permit completely non-invasive characterizations on a full-scale. Several holographic experimental results of typical samples are reported and discussed where DH plays a primary role as a tool gauge for soft matter. ACCEPTED ARTICLE PREVIEW","PeriodicalId":56519,"journal":{"name":"光:先进制造(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69983447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coherent metrology has gained great importance as a branch of highly accurate, non-destructive, precise measurement technology for industrial, aeronautic, medical, and other applications. However, the fringe patterns produced seem to be enigmatic in terms of comprehension and analysis. Many laboratories are involved in improving hardware and software to keep unlocking the unique diagnostic capacities offered through the development of coherent metrology techniques. However, these advancements are not equally well suited for solving problems in all fields of application. The structural diagnosis of artwork is a distinctive field to which coherent metrology is applied. Works of art are unique constructions for which there are strict handling and moral rules aimed at their preservation. Fringe pattern evaluation provides much information about the condition of artwork being investigated, and establishing fringe patterns is one of the most efficient structural deformation and defect detection diagnostic tools. Previous collaborative studies have shown the main fringe patterns and their typical classification with regard to defects. Nevertheless, the complexity of the results prevents defect detection automation based on a fringe pattern classification table. The use of fringe patterns for the structural diagnosis of artwork is important for conveying crucial detailed information and dense data sources that are unmatched compared to those obtained using other conventional or modern techniques. Hologram interferometry fringe patterns uniquely reveal existing and potential structural conditions independent of object shape, surface complexity, material inhomogeneity, and multilayered and mixed media structures, without requiring contact and interaction with the precious surface. Thus, introducing a concept that allows fringe patterns to be considered as a powerful standalone physical tool for direct structural condition evaluation with a focus on artwork conservators’ need for structural diagnosis is crucial. The gravity of this aim intensifies when the particularities of ethics and safety in the field of art conservation are considered. There are ways to obtain the advantages of fringe patterns even when specialized software and advanced analysis algorithms fail to convey usable information. Interactively treating the features of fringe patterns through step-wise reasoning formulates the knowledge basis to automate defect isolation and identification procedures for machine learning and artificial intelligence (AI) development. The transfer of understanding of the significance of these fringe patterns to an AI system through logical steps is this work’s ultimate technical aim. Research on this topic is ongoing.
{"title":"A symmetry concept and significance of fringe patterns as a direct diagnostic tool in artwork conservation","authors":"V. Tornari","doi":"10.37188/lam.2022.018","DOIUrl":"https://doi.org/10.37188/lam.2022.018","url":null,"abstract":"Coherent metrology has gained great importance as a branch of highly accurate, non-destructive, precise measurement technology for industrial, aeronautic, medical, and other applications. However, the fringe patterns produced seem to be enigmatic in terms of comprehension and analysis. Many laboratories are involved in improving hardware and software to keep unlocking the unique diagnostic capacities offered through the development of coherent metrology techniques. However, these advancements are not equally well suited for solving problems in all fields of application. The structural diagnosis of artwork is a distinctive field to which coherent metrology is applied. Works of art are unique constructions for which there are strict handling and moral rules aimed at their preservation. Fringe pattern evaluation provides much information about the condition of artwork being investigated, and establishing fringe patterns is one of the most efficient structural deformation and defect detection diagnostic tools. Previous collaborative studies have shown the main fringe patterns and their typical classification with regard to defects. Nevertheless, the complexity of the results prevents defect detection automation based on a fringe pattern classification table. The use of fringe patterns for the structural diagnosis of artwork is important for conveying crucial detailed information and dense data sources that are unmatched compared to those obtained using other conventional or modern techniques. Hologram interferometry fringe patterns uniquely reveal existing and potential structural conditions independent of object shape, surface complexity, material inhomogeneity, and multilayered and mixed media structures, without requiring contact and interaction with the precious surface. Thus, introducing a concept that allows fringe patterns to be considered as a powerful standalone physical tool for direct structural condition evaluation with a focus on artwork conservators’ need for structural diagnosis is crucial. The gravity of this aim intensifies when the particularities of ethics and safety in the field of art conservation are considered. There are ways to obtain the advantages of fringe patterns even when specialized software and advanced analysis algorithms fail to convey usable information. Interactively treating the features of fringe patterns through step-wise reasoning formulates the knowledge basis to automate defect isolation and identification procedures for machine learning and artificial intelligence (AI) development. The transfer of understanding of the significance of these fringe patterns to an AI system through logical steps is this work’s ultimate technical aim. Research on this topic is ongoing.","PeriodicalId":56519,"journal":{"name":"光:先进制造(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69983685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kai Cui, Yang Li, W. Wei, Qianqian Teng, Tianyu Zhang, Jinzhu Wu, Hongjun Kang, W. Qin, Xiaohong Wu
{"title":"Crystal plane engineering of MAPbI3 in epoxy-based materials for superior gamma-ray shielding performance","authors":"Kai Cui, Yang Li, W. Wei, Qianqian Teng, Tianyu Zhang, Jinzhu Wu, Hongjun Kang, W. Qin, Xiaohong Wu","doi":"10.37188/lam.2022.051","DOIUrl":"https://doi.org/10.37188/lam.2022.051","url":null,"abstract":"","PeriodicalId":56519,"journal":{"name":"光:先进制造(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69984107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haimi Tang, P. Psota, J. Rosowski, C. Furlong, J. Cheng
{"title":"Ultra-high speed holographic shape and displacement measurements in the hearing sciences","authors":"Haimi Tang, P. Psota, J. Rosowski, C. Furlong, J. Cheng","doi":"10.37188/lam.2022.015","DOIUrl":"https://doi.org/10.37188/lam.2022.015","url":null,"abstract":"","PeriodicalId":56519,"journal":{"name":"光:先进制造(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69983568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The invention of Holography by Dennis Gabor goes back to the year 1948. Gabor could show that the complete original wavefront of the object both with its amplitude and phase can be reconstructed by adding a coherent background to a wave coming from an object while recording in a storage medium. However, because no adequate source of coherent light was available at this time, the small coherence length of the mercury lamp forced him to arrange everything along one axis. This setup, known as in-line holography, has the disadvantage that the desired reconstruction is in line with disturbing diffraction orders, and can be separated from these disturbances only by focusing. Gabor finally gave up his investigations and mentioned in 1955 to his collaborator Michael W. Haine, “ It was a very ill wind which I let out now almost eight years ago which blew nobody any good, least of all to myself.” The holographic principle, on which Gabor had set his high hopes, especially with respect to the enhancement of the resolution of the electronic microscope, seemed to retain only the status of a scientific curiosity. But the breakthrough would be achieved a couple of years later. In the early 1960s, Emmett Leith and Juris Upatnieks, two physicists at the University of Michigan, implemented their off-axis scheme as a smart combination of Gabor’s holographic principle with the carrier frequency technique known from side-looking radar. Their famous publication came out 61 years ago in 1961. In this way the twin image problem could be effectively eliminated. However, it resulted in the requirement of increased temporal coherence which could be satisfied using a powerful coherent light source only. Such a source was soon available. In 1958, Charles Townes at the Columbia University, and a Russian research group led by Nicolay Basov and Aleksandr Prokhorov at the Lebedev Institute for Physics, Moscow, simultaneously and independently analyzed the possibilities of applying the principle of the Microwave Amplification by Stimulated Emission of Radiation (MASER) for the optical region of the electromagnetic spectrum. The first operating optical MASER, now known as the laser, was constructed by Maiman and was demonstrated at the Hughes Research Laboratories in Malibu, California, in 1960. The symbiosis of the holographic and laser principle opened the door for a large variety of new technologies and applications in optical imaging, information processing, and metrology. The 1960s were filled with a variety of successful practical applications and innovations such as display or volume holography, computer generated holography, holographic interferometry, holographic nondestructive testing, holographic pattern recognition, and holographic storage technology. Gabor took an active part in this development. 50 years ago, on the occasion of his Nobel lecture at the Imperial Colleges in 1971, he also tried to take a look into the future of holography. Gabor mentioned “However, the
Dennis Gabor发明的全息术可以追溯到1948年。Gabor可以证明，在存储介质中记录时，通过向来自物体的波添加相干背景，可以重建物体的完整原始波前，包括其振幅和相位。然而，由于当时没有足够的相干光源，水银灯的小相干长度迫使他把所有东西都安排在一个轴上。这种设置，被称为在线全息，有缺点，所需的重建是符合干扰的衍射顺序，并且可以从这些干扰中分离只有通过聚焦。Gabor最终放弃了他的调查，并在1955年向他的合作者Michael W. Haine提到，“这是我大约八年前释放的一股非常不好的风，对任何人都没有好处，尤其是对我自己。”加博尔曾寄予厚望的全息原理，特别是关于提高电子显微镜分辨率的全息原理，似乎只保留了一种科学珍品的地位。但这一突破将在几年后实现。在20世纪60年代早期，密歇根大学的两位物理学家Emmett Leith和Juris Upatnieks实现了他们的离轴方案，将Gabor的全息原理与侧视雷达的载频技术巧妙地结合起来。他们著名的出版物出版于61年前的1961年。这样可以有效地消除双象问题。然而，这导致了对时间相干性的要求增加，只有使用强大的相干光源才能满足这一要求。这样的消息来源很快就得到了。1958年，哥伦比亚大学的查尔斯·汤斯(Charles Townes)和莫斯科列别捷夫物理研究所的尼古拉·巴索夫(Nicolay Basov)和亚历山大·普罗霍罗夫(Aleksandr Prokhorov)领导的俄罗斯研究小组同时独立地分析了将微波受激辐射放大(MASER)原理应用于电磁波谱光学区域的可能性。第一台可操作的光学微波激射器，现在被称为激光器，是由梅曼建造的，并于1960年在加利福尼亚州马里布的休斯研究实验室进行了演示。全息和激光原理的共生为光学成像、信息处理和计量学中的各种新技术和应用打开了大门。20世纪60年代充满了各种成功的实际应用和创新，如显示或体全息、计算机生成全息、全息干涉测量、全息无损检测、全息模式识别和全息存储技术。Gabor积极参与了这一发展。50年前，1971年他在帝国理工学院发表诺贝尔奖演讲时，他也试图展望全息术的未来。Gabor说:“然而，在一些重要的领域我们可以做得更多，在这些领域我们急需改进。这是用于存储和显示微全息图的区域。一个更雄心勃勃的计划，可能在更远的未来，是三维电影摄影，不需要像宝丽来这样的观看辅助工具。”基本的
{"title":"Celebrating Holography after 60 years of successful application","authors":"W. Osten, R. Kowarschik, Yuhong Bai","doi":"10.37188/lam.2022.038","DOIUrl":"https://doi.org/10.37188/lam.2022.038","url":null,"abstract":"The invention of Holography by Dennis Gabor goes back to the year 1948. Gabor could show that the complete original wavefront of the object both with its amplitude and phase can be reconstructed by adding a coherent background to a wave coming from an object while recording in a storage medium. However, because no adequate source of coherent light was available at this time, the small coherence length of the mercury lamp forced him to arrange everything along one axis. This setup, known as in-line holography, has the disadvantage that the desired reconstruction is in line with disturbing diffraction orders, and can be separated from these disturbances only by focusing. Gabor finally gave up his investigations and mentioned in 1955 to his collaborator Michael W. Haine, “ It was a very ill wind which I let out now almost eight years ago which blew nobody any good, least of all to myself.” The holographic principle, on which Gabor had set his high hopes, especially with respect to the enhancement of the resolution of the electronic microscope, seemed to retain only the status of a scientific curiosity. But the breakthrough would be achieved a couple of years later. In the early 1960s, Emmett Leith and Juris Upatnieks, two physicists at the University of Michigan, implemented their off-axis scheme as a smart combination of Gabor’s holographic principle with the carrier frequency technique known from side-looking radar. Their famous publication came out 61 years ago in 1961. In this way the twin image problem could be effectively eliminated. However, it resulted in the requirement of increased temporal coherence which could be satisfied using a powerful coherent light source only. Such a source was soon available. In 1958, Charles Townes at the Columbia University, and a Russian research group led by Nicolay Basov and Aleksandr Prokhorov at the Lebedev Institute for Physics, Moscow, simultaneously and independently analyzed the possibilities of applying the principle of the Microwave Amplification by Stimulated Emission of Radiation (MASER) for the optical region of the electromagnetic spectrum. The first operating optical MASER, now known as the laser, was constructed by Maiman and was demonstrated at the Hughes Research Laboratories in Malibu, California, in 1960. The symbiosis of the holographic and laser principle opened the door for a large variety of new technologies and applications in optical imaging, information processing, and metrology. The 1960s were filled with a variety of successful practical applications and innovations such as display or volume holography, computer generated holography, holographic interferometry, holographic nondestructive testing, holographic pattern recognition, and holographic storage technology. Gabor took an active part in this development. 50 years ago, on the occasion of his Nobel lecture at the Imperial Colleges in 1971, he also tried to take a look into the future of holography. Gabor mentioned “However, the","PeriodicalId":56519,"journal":{"name":"光:先进制造(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69983642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quantitative phase microscopy by digital holography is a good candidate for high-speed, high precision profilometry. Multi-wavelength optical phase unwrapping avoids difficulties of numerical unwrapping methods, and can generate surface topographic images with large axial range and high axial resolution. But the large axial range is accompanied by proportionately large noise. An iterative process utilizing holograms acquired with a series of wavelengths is shown to be effective in reducing the noise to a few micrometers even over the axial range of several millimeters. An alternate approach with shifting of illumination angle, instead of using multiple laser sources, provides multiple effective wavelengths from a single laser, greatly simplifying the system complexity and providing great flexibility in the wavelength selection. Experiments are performed demonstrating the basic processes of multi-wavelength digital holography (MWDH) and multi-angle digital holography (MADH). Example images are presented for surface profiles of various types of surface structures. The methods have potential for versatile, high performance surface profilometry, with compact optical system and straightforward processing algorithms.
{"title":"Phase microscopy and surface profilometry by digital holography","authors":"Myung K. Kim","doi":"10.37188/lam.2022.019","DOIUrl":"https://doi.org/10.37188/lam.2022.019","url":null,"abstract":"Quantitative phase microscopy by digital holography is a good candidate for high-speed, high precision profilometry. Multi-wavelength optical phase unwrapping avoids difficulties of numerical unwrapping methods, and can generate surface topographic images with large axial range and high axial resolution. But the large axial range is accompanied by proportionately large noise. An iterative process utilizing holograms acquired with a series of wavelengths is shown to be effective in reducing the noise to a few micrometers even over the axial range of several millimeters. An alternate approach with shifting of illumination angle, instead of using multiple laser sources, provides multiple effective wavelengths from a single laser, greatly simplifying the system complexity and providing great flexibility in the wavelength selection. Experiments are performed demonstrating the basic processes of multi-wavelength digital holography (MWDH) and multi-angle digital holography (MADH). Example images are presented for surface profiles of various types of surface structures. The methods have potential for versatile, high performance surface profilometry, with compact optical system and straightforward processing algorithms.","PeriodicalId":56519,"journal":{"name":"光:先进制造(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69983700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Zvagelsky, Frederik Mayer, D. Beutel, C. Rockstuhl, G. Gomard, M. Wegener
In recent years, multi-photon 3D laser printing has become a widely used tool for the fabrication of micro- and nanostructures for a large variety of applications. Typically, thorough sample characterisation is key for an efficient optimisation of the printing process. To date, three-dimensional microscopic inspection has usually been carried out on finished 3D printed microstructures, that is, using ex-situ approaches. In contrast, in-situ 3D characterization tools are desirable for quickly assessing the quality and properties of 3D printed microstructures. Along these lines, we present and characterise a Fourier-domain optical coherence tomography (FD-OCT) system that can be readily integrated into an existing 3D laser lithography setup. We demonstrate its capabilities by examining different 3D printed polymer microstructures immersed in a liquid photoresist. In such samples, local reflectivity arises from the (refractive-index) contrasts between the polymerised and non-polymerised regions. Thus, the refractive index of the printed material can be extracted. Furthermore, we demonstrate that the reflectivity of polymer-monomer transitions exhibits time-dependent behaviour after printing. Supported by transfer-matrix calculations, we explain this effect in terms of the time-dependent graded-index transition originating from monomer diffusion into the polymer matrix. Finally, we show exemplary 3D reconstructions of printed structures that can be readily compared with 3D computer designs.
{"title":"Towards in-situ diagnostics of multi-photon 3D laser printing using optical coherence tomography","authors":"R. Zvagelsky, Frederik Mayer, D. Beutel, C. Rockstuhl, G. Gomard, M. Wegener","doi":"10.37188/lam.2022.039","DOIUrl":"https://doi.org/10.37188/lam.2022.039","url":null,"abstract":"In recent years, multi-photon 3D laser printing has become a widely used tool for the fabrication of micro- and nanostructures for a large variety of applications. Typically, thorough sample characterisation is key for an efficient optimisation of the printing process. To date, three-dimensional microscopic inspection has usually been carried out on finished 3D printed microstructures, that is, using ex-situ approaches. In contrast, in-situ 3D characterization tools are desirable for quickly assessing the quality and properties of 3D printed microstructures. Along these lines, we present and characterise a Fourier-domain optical coherence tomography (FD-OCT) system that can be readily integrated into an existing 3D laser lithography setup. We demonstrate its capabilities by examining different 3D printed polymer microstructures immersed in a liquid photoresist. In such samples, local reflectivity arises from the (refractive-index) contrasts between the polymerised and non-polymerised regions. Thus, the refractive index of the printed material can be extracted. Furthermore, we demonstrate that the reflectivity of polymer-monomer transitions exhibits time-dependent behaviour after printing. Supported by transfer-matrix calculations, we explain this effect in terms of the time-dependent graded-index transition originating from monomer diffusion into the polymer matrix. Finally, we show exemplary 3D reconstructions of printed structures that can be readily compared with 3D computer designs.","PeriodicalId":56519,"journal":{"name":"光:先进制造(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69983710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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