University of Shanghai for Science and Technology, China
Professor SongLin Zhuang, was born in 1940. In 1995, he was selected as academician of the Chinese Academy Engineering. Currently, he is the dean and professor of the School of Optical-Electronics and Computer Engineering, University of Shanghai for Science and Technology. He also works as a visiting professor in Tsinghua University, Shanghai Jiaotong University, Fudan University, and Zhejiang University. He is the fellow of International Society of Optical Engineering, Optical Society of America, honor chairman of China Instrument and Control Society, council member of the Chinese Optical Society, specialist of China's Lunar Exploration Project, associate director of Higher Education Instrument Science and Technology teaching Steering Committee (Ministry of Education). His research interests are graded refractive index optical materials, theory of vector mode status for grating diffraction, optical supperresolution imaging metamaterials and high-density optical storage technology. He is the pioneer of CAD for optical system in the country and he is acclaimed as “one of the most contributor for modern white-light optical information processing”. In recent years, he leaded his team in developing the active terahertz body security inspection system and the terahertz time domain spectroscopy system for detection of the organics. His terahertz laboratory recently was approved “Cooperative Innovation Centre of Terahertz Science”by Shanghai government, which is more than 10,000 m2. Furthermore, two doctors instructed by him have been chosen as“the National 100 excellent PhD thesis”and nomination of “the National 100 excellent PhD thesis”in 2009 and 2013.
Speech title: Terahertz Spectroscopy and Imaging Technology: From Source to System
Abstract: The vibration and rotation frequencies of some organic and bio molecules are located in terahertz region. Therefore, by using terahertz spectroscopy technology, the macro-organic material can be detected and identified. Furthermore, because of the good transmission and low photon energy, terahertz wave is also considered as an option for homeland security check. m-i-n diode based on intrinsic GaAs for terahertz emitter is fabricated by University of Shanghai for Science and Technology (USST), whose operation frequency can reach 4.2 THz. Furthermore, some terahertz functional devices are also developed, i.e., broadband high efficiency terahertz absorber, whose absorption can be more than 95% from 0.6-2.6 THz. Based on the above terahertz emitter and functional material, an fast scan and fiber based terahertz spectroscopy system is fabricated. The system can realize 0.1 s/spectrum scan for drug functional group identification and cancel cell detection. Moreover, an active terahertz imaging system for homeland security is also developed. The system is based on multi detectors and fast vibration scan mirror, which can realize a scan ~1.3 s/ person with the resolution about 1.5 cm.
David J. Brady
Duke University, USA
David J. Brady is the Fitzpatrick Family Professor of Photonics at Duke University and Professor of Electrical and Computer Engineering at Duke Kunshan University. Professor Brady is the author of the text “Optical Imaging and Spectroscopy” and is a fellow of IEEE, OSA and SPIE. He won the 2013 SPIE Denis Gabor Award for his work on compressive holography. He has developed numerous computational imaging systems for visible, infrared, x-ray and millimeter wave applications. His work has focused particularly on compressive tomography and on hyperspectral imaging. In 2012, Brady and his team developed the world’s first terrestrial gigapixel camera.
Speech title: Resolution and Camera Size, Weight and Power
Abstract: Parallel optical and electronic processing enables gigapixel-scale cameras. This talk reviews recently developed gigapixel cameras and considers current and future limits on camera pixel capacity as a function of size, weight and power. Using multiscale lens designs, it is possible to build cameras resolving more than 10 gigapixels per liter camera volume. However, the electronic processing volume in current gigapixel cameras exceeds optics volume by more than 10x. We consider novel processing architectures and algorithms to reduce electronical power and volume requirements.
Utrecht University, Netherlands
Allard Mosk (1970) started his physics career in ultra-cold atomic gases with work in Amsterdam (Ph.D. 1994), Heidelberg, and Paris, performing the first observation of a Feshbach resonance in Li, and of photo-association of H. In 2003 he joined the nano-photonics group of Ad Lagendijk and Willem Vos at the University of Twente where he pioneered wave-front shaping methods to focus and image through strongly scattering media. In 2015 he was elected Fellow of the Optical Society (OSA). Since 2015 he leads a group at Utrecht University, The Netherlands, where he studies statistical properties of light in complex scattering media with a view on imaging and metrology.
Speech title: Imaging and Metrology Using Scattered Light
Abstract: Random scattering of light, which causes the opaqueness of paper, paint and biological tissue is an obstacle to imaging and focusing of light. Scattered laser light produces random interference patterns, known as speckle, that contain scrambled information pertaining to the environment of the scatterers, and that make imaging difficult. On the other hand, in some systems scattered light gives access to information that cannot be obtained through ballistic light. For example, scattering can increase the effective numerical aperture of an optical system and thereby improve the resolution. To be able to use this information the scattering should be carefully controlled and characterised. I will show several recent methods to use information to control and focus focus scattered light and to use scattered light to obtain relevant information and images.
National Taiwan University, Taiwan, China
Professor Din Ping Tsai received Ph.D in Physics from University of Cincinnati, USA in 1990. He worked at Microlithography Inc., California, USA; Ontario Laser and Lightwave Research Center, Toronto, Canada; and National Chung Cheng University, Taiwan from 1990 to 1999. He joined Department of Physics, National Taiwan University as an Associate Professor in 1999, and became Professor and Distinguished Professor in 2001 and 2006, respectively. He served as the Director General of the Instrument Technology Research Center (NARL) located in Hsinchu Science Park, Taiwan from 2008 to 2012. He is the Director and Distinguished Research Fellow of Research Center for Applied Sciences, Academia Sinica since 2012. He is a Fellow of AAAS, APS, IEEE, OSA, SPIE, TPS and Electro Magnetics Academy. He is also Academician of Asia Pacific Academy of Materials and Corresponding Member of International Academy of Engineering (IAE). He currently serves as Editor of Progress in Quantum Electronics, Associate Editor of Journal of Lightwave Technology, Member of Editorial boards of Physical Review Applied, Applied Physics Letters Photonics, Optics Communications, Plasmonics, ACS photonics, Small Method and Optoelectronics Letters, respectively. He is now the President of Taiwan Information Storage Association. He was the Director of the Board of SPIE and Member of IEEE/LEOS Nanophotonics Committee; OSA Fellows & Honorary Members Committee; SPIE Fellow Committee; IEEE Joseph F. Keithley Award Committee; OSA and IS&T Edwin H. Land Medal Committee; respectively. He was also President of Taiwan Photonics Society; Chairman of IEEE Instrument and Measurement Society Taipei Chapter; and Chairman of the SPIE Taiwan chapter.
Speech title: Metasurface for Photonics Application in Demand
Abstract: The functionalities of traditional optical component are mainly based on the phase accumulation through the propagation length, leading to a bulky optical component like lens and waveplate. Metasurfaces composed of two-dimensional (2D) artificial structures have attracted a huge number of interests due to their ability on controlling the optical properties including electromagnetic phase as well as amplitude at a subwavelength scale. They therefore pave a promising way for the development of flat optical devices and integrated optoelectronic systems. In this talk, important research topics for photonics applications based on metasurfaces will be performed and discussed. Examples of Beam deflection, muti-dimensional holographic imaging, versatile polarization generation and analysis, multi-functional and tunable metadevices, engineering non-radiating anapole mode in free space and achromatic metasurface devices will be shown.
Utsunomiya University, Japan
Yukitoshi Otani is a professor of Department of Optical Engineering, Utsunomiya University, JAPAN. He received his doctor's degree from the University of Tokyo in 1995. After working for a brief period at HOYA Corp., he worked at Tokyo University of Agriculture and Technology as a research associate and an associate professor until 2010. He was a visiting professor at College of Optical Sciences, the University of Arizona from 2004 to 2005. He joined the Center for Optical Research and Education(CORE), Utsunomiya University as a professor from April 2010. His current interests include polarimetry, interferometry, optical measurement and optomechatoronics. He is a SPIE fellow from 2010. He was a board member of the Japan Society for Precision Engineering from 2013 to 2016, the general chair of the International Symposium on Optomechatronic Technology, ISOT 2016 and the general char of the Optics and Photonics Japan, OPJ2016. He is working the head of Polarization Science and Engineering Group in OSJ from 2015.
Speech title: Real-Time Phase Analysis of A Bio Sample by Differential Interference Contrast Microscope Using Pixelated Polarization Camera
Abstract: A polarization technology has become important in the field of optical science and engineering. We have proposed a new technology by a differential interference contrast (DIC) microscope with a polarization camera which has a linear micro-pixel polarizer array in adjacent 4 pixels aligned to 0, 45, 90 and 135° of azimuthal direction. It shows a real-time analysis for phase and amplitude of a transparent material. Tyo’s algorithm is employed to increase a spatial resolution of the polarization camera. We demonstrated to measure real-time phase distribution inside of an alive fish and its egg as bio-samples and succeeded to show a 3D reconstruction of a blood vessel, a beating heart and a backbone of a Medaka fish as same as a confocal microscope without staining method.
Utsunomiya University, Japan
Okihiro Sugihara received the D.E. degrees in electrical engineering from Keio University, Yokohama, Kanagawa, Japan, in 1991. He was a Research Assistant and an Associate Professor at Shizuoka University, Hamamatsu, Japan, where he worked on organic nonlinear optical devices. In 2003, he joined Tohoku University, Sendai, Japan, where he was engaged in polymeric lightwave devices. In 2014, he joined Utsunomiya University. He is currently a professor at the Center for Optical Research and Education, Utsunomiya University. Dr. Sugihara is a project leader of “Optical Interconnect Devices Using Photonic Polymers”, JST, Japan.
Speech title: Gigabit and Multigigabit Optical Transmission System Using Multimode Optical Fibers for Next Generation In-Vehicle Communication
Abstract: With a demand of high bandwidth in-vehicle network, optical fiber is a potential candidate to realize gigabit and multigigabit data transmission for the purpose of future advance driver assistance system and autonomous driving. We are now engaging in an international standardization and dissemination project for high-speed communication network performance over multimode optical fibers. Recent research and standardization progress of components and system for such ultrahigh bit-rate optical transmission will be presented.
University of Shanghai for Science and Technology, Shanghai
Sen Han obtained his Ph.D.in Optical Engineering from University of Stuttgart, Germany. Dr. Han is a Professor of University of Shanghai for Science and Technology and one of Co-Founder of H&L Instruments. He is both a SPIE Fellow and an Adjunct Professor of University of Arizona, USA. Dr. Han won R&D 100 Awards twice in USA.
Speech title: Transmitted Wavefront of Multiple-Wavelength Expressed by Related Zernike Coefficients
Abstract: Wavefront aberration can reflect the performance of optical systems, the test of wavefront aberration is convenient to express in Zernike polynomials form. Transmission optical system wavefront changes with wavelength, testing at design wavelength is critical for the optical system, from now on only a few wavelength wavefront can be tested by laser interferometer. A new idea is put forward in this paper, transmission optical system wavefront can be calculated at any wavelength utilizing the relationship between transmitted wavefront Zernike coefficients and wavelength. The optical system was modeled and Zernike coefficients at different wavelength were collected by Zemax, then the coefficients were fitted by Matlab curve fitting tool, finally we found Conrady-Zernike formula. The maximum error of the calculated Zernike coefficients is within 1%. The results show that the Zernike coefficients and the wavelength are basically consistent with Conrady-Zernike formula.
University of Liverpool, UK
Dr. Shen received his PhD degree from Nanjing University in 1992. After that he held various positions at Southeast University, Heidelberg University and Cambridge University. Currently he is a full professor at the University of Liverpool. Dr. Shen has been working on terahertz-related technology for many years, first as a Research Associate (2001-2004) at the Cavendish Laboratory, University of Cambridge, and then as a Senior Scientist (2004-2007) at TeraView Limited, Cambridge. He served as the TPC Chair of the 10th UK/Europe-China Workshop on Millimetre-Waves and Terahertz Technologies in 2017. Dr. Shen has been awarded 7 patents and published 5 book chapters and over 180 conference & journal publications with over 4700 combined citations and an h-index of 37. His current research interests include the development of novel THz and infrared imaging technologies with a focus on the exploitation of their applications in industry and science.
Speech title: Online monitoring and off-line inspection of pharmaceutical pellet coatings using optical coherence tomography and THz imaging
Abstract: The terahertz (THz) region of the electromagnetic spectrum spans the frequency range between the mid-infrared and the microwave. Over the last decade or so, THz technology has advanced considerably with THz imaging instruments now commercially available. One of the distinct features of THz imaging is its 3D imaging capability, seeing not only the surface features but also the internal structures of a sample. On the other hand, in the near-infrared region optical coherence tomography (OCT) has also proven to be a non-invasive and cross-sectional imaging technique that permits, for example, 3D images with micrometre resolution to be obtained. In this talk, I will present our recent work on the development of an integrated THz and OCT online sensor for intelligent monitoring of high-value manufacturing and a novel OCT sensor for healthcare applications.
University of Fukui, Japan
Prof. Motoharu Fujigaki received his BE and ME degrees in mechanical engineering from Osaka University in 1990 and 1992, respectively. He received his doctoral degree from Osaka University in 2001. He was working in NABCO Ltd. from 1992 to 1995. He moved to Department of Opto-Mechatronics, Faculty of Systems Engineering, Wakayama University in 1995 as a research associate. He became an associate professor in 2003. He moved to Human and Artificial Intelligent Systems, Graduate School of Engineering, University of Fukui as a full professor in 2015. He is interested in optical metrology using image processing, especially 3D shape measurement using gating projection method, deformation measurement using phase analysis method used for structural health monitoring and small displacement and strain distribution measurement using laser interferometry.
Speech title: Camera Calibration-free 3D Shape Measurement Using Grating Projection Method
Abstract: Authors proposed a feature quantity type whole-space tabulation method (F-WSTM) as a camera calibration-free 3D shape measurement. 3D shape measurement using grating projection method is useful method for many fields. However, the method is not robust for vibrating of the measurement device. Especially, the optical positions of an imaging sensor and lenses are deformed easily owing to vibration. The F-WSTM overcomes these weak points. In this paper, the principle and the experimental result are shown.
University of Connecticut, USA
Dr. Guoan Zheng received his Ph.D. degree from Caltech in 2013. He is currently an assistant professor at the University of Connecticut. He is the recipient of Lemelson-MIT Caltech Student Prize for his development of chip-scale microscopy platforms in 2011. He also received the Caltech Demetriades Thesis Prize for his development of Fourier ptychography technology in 2013. His current research focuses on the development of novel imaging and sensing techniques for biomedical applications. Dr. Zheng has been awarded 10 patents, published 1 book and over 70 conference & journal publications. The Fourier ptychography developed by him and his colleagues has been written into the famous textbook, Introduction to Fourier Optics (4th edition) by Goodman.
Speech title: Fourier ptychographic imaging
Abstract: Fourier ptychography (FP) is a recently developed phase retrieval technique for wide-field, high-resolution imaging. This technique stitches together many variably illuminated, low-resolution measurements in the Fourier space to expand the frequency passband and recover the high-resolution complex sample image. Without involving any mechanical scanning, it facilitates gigapixel imaging in a simple and robust manner. In this talk, I will discuss the principle of the FP approach and its applications in microscopy, quantitative phase imaging, 3D holographic imaging, and macroscopic imaging. I will discuss how to extend the FP approach for other imaging settings. The FP innovation may provide new insights for the development of high-resolution, high-throughput imaging platforms using photon, X-ray, and electron.
The Hong Kong Polytechnic University, Hong Kong, China
Dr. Wen CHEN received PhD degree from the National University of Singapore in 2010. Dr. Chen conducted extensive research as Research Associate (2010) and Research Fellow (2011-2015) in the Department of Electrical and Computer Engineering of the National University of Singapore. He was a visiting scholar in Rowland Institute, Harvard University, U.S.A. from March 2013 to June 2013. Dr. Chen is currently an Assistant Professor in the Department of Electronic and Information Engineering, The Hong Kong Polytechnic University. Dr. Chen has published more than 80 international journal and conference papers, and some publications have been highlighted or reported, such as AIP press release. He currently fulfils some professional services, such as an Editorial Board Member for “Scientific Reports” Journal, an Associate Editor for “IEEE Access” Journal and an active reviewer for many important journals in his research field. He was recognized as an outstanding reviewer for OSA publishing (Optical Society of America) in Aug. 2016. He actively attended academic activities, and was awarded to attend Global Young Scientists Summit @ Singapore One-North 2014. Dr. Chen's current research interests focus on imaging systems, single-pixel imaging, coherent diffractive imaging, optoelectronic systems, phase retrieval, digital holography, computer-generated hologram, microscopy, information optics, signal/image processing, big data, machine/deep learning, and compressed sensing.
Speech title: Novel applications using ghost imaging principles
Abstract: Single-pixel ghost imaging principles have attracted much current attention in various applications, e.g., optical encoding, imaging through scattering media, and remote sensing. In this invited talk, the novel applications using single-pixel ghost imaging principles are presented and discussed, e.g., optical encoding and decoding, optical authentication and high-quality object reconstruction. It is hoped that this invited talk could shed some light on the further developments of single-pixel ghost imaging principles for more applications.
Iowa State University, USA
Dr. Beiwen Li is an Assistant Professor of Mechanical Engineering at Iowa State University. He received his Ph.D. from Purdue University in August, 2017. His research interests include experimental mechanics, 3D optical sensing, multi-scale optical metrology, machine vision, and bio-photonic imaging. He has published 18 journal papers and co-authored two book chapters. Two of his journal papers were highlighted on the cover page of Applied Optics and Optics Express. Dr. Li received different awards including Dean’s Fellowship from Iowa State University and the Lambert Fellowship from Purdue University. Dr. Li was also the recipient of the Optics and Photonics Educational Scholarship of SPIE.
Speech title: Superfast Photomechanics Testing of Robotic Flapping Wings
Abstract: The flapping flight study is important to a variety of fields including biology, aerospace engineering and robotics. Over the years, the flapping flight study has been enhanced with experimental tools such as high-speed 3D imaging with photogrammetry. However, dense full-field mechanics testing of flapping wings is not well-documented so far mainly because of the limited spatial resolutions of photogrammetry based methods. Conversely, the structured light method with defocused binary stripe illumination can perform superfast (e.g. several kHz) high-resolution 3D imaging, and thus has the potential for dense mechanics analysis. In this talk, I will present our preliminary testing with a robotic bird. Specifically, I will talk about: (1) our superfast 3D imaging method for the robotic bird; (2) our point tracking method with geodesic computation; and (3) our strain computational method based on Kirchhoff-Love shell theory.
Linkoping University, Sweden
Dr. Valyukh received his PhD degree from Taras Shevchenko National University of Kyiv, Ukraine, in 2003. After that he conducted research at Dalarna University and Swedish LCD Center (Borlange, Sweden). Several times from 2005 up to 2014, he was a visiting researcher at the Hong Kong University of Science and Technology. Since 2010 Dr. Valyukh has been an assistant professor at Linkoping University (Sweden), and since 2012 he is a docent (associated professor) at this University. Dr. Valyukh is an author of 11 patents, 1 book and over 80 scientific works. The area of his interests is optical simulations (interaction of light with complex structured media, design and optimization of optical devices) and measurements (spectroscopic ellipsometry and polarimetry).
Speech title: Advanced Tunable Diffractive Optical Elements
Abstract: Diffractive optical elements based on liquid crystals will be reported. We investigated formation of a desired liquid crystal director distribution by the use of inhomogeneous alignment. Such an approach enables one to control the optical element by a uniform electric field when only two continues electrodes are needed. Physical limitations and potential abilities of liquid crystal diffractive optical elements will be discussed. As examples of practical applications, a reflective lens utilizing cholesteric liquid crystal and a projection optical system for an augmented reality display built into a contact lens or glasses will be demonstrated.
Jinan University, China
Professor Jingang Zhong is currently with the Department of Optoelectronic Engineering and the Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Educational Institutes, Jinan University, Guangzhou, China. He mainly investigates in the fields of single-pixel imaging, three-dimensional profilometry, digital holography, optical microscopy, surface plasmon resonance biosensors, etc.
Speech title: Fourier Single-pixel Imaging: Recent Progress
Abstract: Fourier single-pixel imaging (FSI) is a recently proposed computational imaging technique which allows for producing high-quality images by using a detector without spatial resolution. FSI is a breakthrough for the field, as it well tackles the problems of low quality and low efficiency of single-pixel imaging. More recently, FSI has been extended to three-dimensional imaging, multi-modality imaging, dynamic imaging, and encrypted imaging. What’s more, FSI has been demonstrated that it outperforms Hadamard single-pixel imaging in terms of efficiency. The recent progress of FSI adds the value of practical application of FSI. And FSI may find important applications where the pixelated detectors are unavailable.
The Institute of Electronic Structure and Laser of the Foundation for Research and Technology-Hellas, Greece
Principal project coordinator and laboratory head at IESL. Employed as research scientist at FORTH/IESL laser applications division since May 1996. Since then she has established and leads the Display Holography and Holographic Metrology laboratory. Obtained a BSc in Optical Physics - TEIA Univ. Athens Gr, Post-Graduate Diploma in Optical Holography - RCA Univ London UK, MSc in Material Science EMP Athens Polytechnic, MPhil in Art Conservation RCA-ICSTM-V&A London UK, and PhD in Applied Science - Univ. Sunderland. Research activities range from the development of optical holographic techniques for display holography and for ND material testing and artwork structural defect analysis, detection and identification of structural defects on artworks, antifraud technologies, physicomechanical deterioration mechanisms, environmental effects and transportation impact, photomechanical effects of laser ablation, optical instrumentation, optical prototype system design and experimental verification, optical prototype system development, structural assessment, on-field campaigns methodology planning, innovation and research development, philosophy of science and physical philosophy.
Speech title: Develoment Of Portable Interferometry System For Displacement Measurement In Cultural Heritage Applications
Abstract: Cultural Heritage is concerned with objects and materials that witness the historical evolution and human civilisation and are due to be inheritent to next generations. As such prevention of damage and failure is an ultimate neverending aim in art conservation science. Interferometry techniques offer the spatial sensitivity to assess minor changes prior to damage while important ethic principles of non destructivity and non invasivity are satisfied as basic requirements for artobject examnation. Scientific laboratories explore the trends in modern instrumentation to adjust it to the needs of Cultural heritage fields. In this context the development of a portable interferometry system based on the fundamentals of holographic and speckle interferometry satisfying the limitations and overpassing the state of the art in on-field measurements for structural diagnosis is presented with examples from represantative application fields.
Shanghai Synchrotron Radiation Facility, China
Education Experiences: 1991.9-1995-7, Bachelor degree of science at the Northwest Polytechnic University and my major was metal material and heat treatment. 2001.9-2005.7 PhD degree of science at Shanghai institute of optics and fine mechanics, Chinese Academy of Science. Now is in charge of optical metrology in SSRF(Shanghai Synchrotron Radiation Facility); Shanghai institute of applied physics, Chinese Academy of Science.
Speech title: Long Trace Profiler at SSRF
Abstract: LTP-1200 is the first long trace profiler (LTP) developed by Shanghai Synchrotron Radiation Facility (SSRF). Upgrade of the LTP-1200 started from 2015 to improve the slope error range of measurement and system accuracy. A new optical system has been designed, and the entire optical elements, such as pi-phase plate, laser and detector have also been replaced. In particular, slope error of ±4mrad measurement range, slope resolution of 2nrad and the lateral resolution of 0.2mm are obtained after the upgrade process.
Sichuan University, China
Dr. Lei Li is an associate professor at the department of School of Electronics and Information Engineering, Sichuan University. He received his Ph.D. and B.S. from Sichuan University in 2013 and 2008. He was a research assistant at Institute of Optics and Electronics, Chinese Academy of Sciences, from 2013 to 2014. In 2015, he was exceptionally promoted to associate professor in Sichuan University. His research interest focuses on liquid optical device, optical system design, and 3D display. He is the author or coauthor of more than 30 papers in peer-reviewed journals and conferences and one book chapter in his research career. He is the member for several professional organizations, also reviewer for many prestigious peer-review journals in optical sciences related fields.
Speech title: Optofluidic Devices for Imaging System
Abstract: Optofluidic devices such as liquid lenses, liquid irises are important elements of next generations of imaging system. In this talk, we report several adaptive imaging systems based on optofluidic devices. The proposed system can realize continuous zoom change and correct aberrations during the tuning range. voltages and pneumatic actuation are used to control the system. And, the proposed system is very compact without any mechanical movement part.
National University of Defense Technology, China
Dr. Lin Zhou is an associate professor at the National University of Defense Technology (NUDT) in China. He received his Ph.D. and B.S. from NUDT in 2008 and 2003. He had worked with Optics & Metrology Group in Brookhaven National Laboratory (BNL) as a visiting scientist for one year. His research field is optical fabrication and test. He is in charge of ion beam figuring group in NUDT. He won the 2nd prize of National Award for Technological Invention once, and was supported by the Program for New Century Excellent Talents in University.
Speech title: Slope-based Figuring Method to Fabricate Grazing-Incidence Reflective Optics
Abstract: The raw measurement output data of grazing-incidence reflective optics are commonly slope profiles, not height profiles. However, the traditional figuring processes are based on surface height profiles, not on surface slope profiles. Therefore, the raw slope profiles should be converted to height profiles in figuring processes, and this conversion will result in cumulative errors. As for this problem, we propose a slope-based figuring (SF) method which uses the raw slope data instead of the converted height data to fabricate grazing-incidence reflective optics. Both 1D SF model and 2D SF model are established in this study. The slope removal functions and algorithms used to calculate dwell times are discussed as well. Finally, some figuring results are presented.
University of Wollongong, Australia
Jiangtao Xi received BE from Beijing Institute of Technology, China in 1982, ME from TsingHua University, China in 1985 and Ph.D from the University of Wollongong, Australia in 1996, all in electrical engineering. He was a Postdoctoral Fellow at the Communications Research Laboratory, McMaster University, Ontario, Canada from 1995 to 1996, a Member of Technical Staff at Bell Laboratories, Lucent Technologies Inc., NJ, USA from 1996 to 1998. He worked as the Chief Technical Officer at TCL IT Group Co, China from 2000 to 2002. In 2003 he rejoined the University of Wollongong as a Senior Lecturer and he is currently a full Professor and the Head of School of Electrical, Computer and Telecommunications Engineering. His research interests include signal processing and its applications in various such areas as instrumentation and measurement, as well as communications.
Speech title: Fringe Pattern Analysis using Message Passing Based Expectation Maximization for Fringe Projection Profilometry
Abstract: Fringe projection profilometry (FPP) is a popular optical 3-D imaging approach, in which the images of deformed fringe patterns are analyzed to extract object surfaces (i.e., height maps of object surfaces). As an object surface normally exhibits smooth areas, height correlations of an object surface can be used to denoise and improve the measurement performance of the FPP. In this talk, we use autoregressive (AR) models with unknown parameters to describe the unknown height correlations and formulate the FPP analysis problem under the framework of expectation maximization (EM). With EM, the unknown AR model parameters are determined based on observations, and the estimates of the heights with their correlations exploited can also be extracted. To deal with the large-scale problem, a message passing based implementation of the formulated EM problem is studied and the relevant message updating rules are developed. The presented approach has a linear complexity and it allows parallel processing due to the nature of message passing. Simulation and experimental results demonstrate a significant performance improvement by the proposed approach.
Southeast University, China
Dr. Wang Chenxing received her Ph.D. degree from Southeast University in 2013, and was a research fellow at Nanyang Technological University in Singapore from 2014 to 2016. She is now an associate professor in Southeast University. Her research interests include optical measurement, advanced signal processing, precision engineering and automation.
Speech title: SEMD Profilometry
Abstract: Surface profiling in dynamic states is widely needed, which can be implemented using single-frame projection (SP) of structural illumination. The classic Fourier Transform Profilometry is disturbed by the possible complex background, which limits the ability for complicated surface or the measurement in harsh environment. Empirical mode decomposition (EMD) combined with Hilbert Transform (HT) has strong capability to process complex nonlinear signals, which has been successfully developed and applied to process fringe patterns. The recently developed Sinusoidal-assisted EMD (SEMD) profilometry will be introduced in this talk, including the solutions to the challenging issues of SP system. The newly proposed SEMD methods in different spatial dimensions will be described and investigated in various applications of optical fields.
Beihang University, China
Dr. Bing Pan is a full professor in School of Aerospace Science & Engineering at Beihang University (BUAA), China. He received his Ph.D degree in Mechanical Engineering from Tsinghua University in 2008. After working with Professor Anand Asundi in Nanyang Technological University (Singapore) as a postdoctor, he joined Institute of Solid Mechanics, BUAA in 2009. His current research interests mainly focus on advanced optical techniques and their applications in experimental mechanics, especially the digital image correlation, digital volume correlation techniques for surface or internal deformation measurement of solid materials and structures, as well as new experimental techniques for characterizing thermo-mechanical behavior of hypersonic materials and structures. He has published 93 peer-reviewed articles in international journals, and six of these papers were selected as ESI highly cited papers. All his publications have been cited more than 3500 times according to Web of Science with a h-index of 27. Dr. Pan was selected for Youth Changjiang Scholars (MOE) in 2016, and won the National Natural Science Funds for Excellent Young Scholar in 2013.
Speech title: Recent Progresses in Digital Volume Correlation
Abstract: In this talk, we report the following important progresses recently made in the basic theory and practical implementation of digital volume correlation (DVC) for full-field internal deformation measurement. First, we present an accurate and efficient 3D inverse compositional Gauss-Newton (IC-GN) algorithm for subvoxel registration, which outperforms existing algorithms in terms of computational efficiency and noise robustness. Second, we propose a flexible and accurate DVC method scale to high-resolution volume images with up to billions of voxels. This advanced DVC technique combines a novel layer-wise reliability-guided displacement tracking strategy with the 3D IC-GN algorithm, and addresses the challenge of processing high-resolution volumetric images in personal computers with limited random-access memory. Third, we establish a self-adaptive DVC method for full-automatic and accurate internal deformation, which can determine optimal subvolume sizes and shape functions at each measurement point according to image noise level, image gradients and local deformation feature. Final, we investigate the displacement and strain errors in DVC due to the self-heating effect of a commercially available X-ray scanner. To realize high-accuracy internal deformation measurement with DVC, we develop an effective and easily implemented reference sample compensation (RSC) method for in-situ systematic error correction.
University of Huddersfield, UK
Dr Feng Gao is a Reader in Metrology and Instrumentation at the School of Computing and Engineering, University of Huddersfield. His main research interests are in the field of surface metrology and advanced optics. He studied precision measurement and instrumentation as an undergraduate and postgraduate student in Tianjin University. After his postgraduate study he worked as an Assistant Engineer and Engineer in the National Institute of Metrology of China and as a visiting scholar at the PTB, Germany. Then he became a Ph.D. student in Coventry University. Following his Ph.D. study, he worked as a Research Associate in Loughborough University. Subsequently he joined the Centre of Precision Technologies of University of Huddersfield as a senior research fellow.
Speech title: Embedded Metrology for Surface Measurement and Inspection
Abstract: Surface quality becomes increasingly important due to the widely use of nanoscale and ultra-precision structured and freeform surfaces in many applications such as optics, MEMS, micro fluidics and the micro moulding industries. These industries all critically rely on ultra-precision surfaces. Embedded metrology providing metrology on the manufacturing platform, enabling measurement without the removal of the work piece. By integration of metrology sensor or system upon the manufacturing platform can lead to a better control of the quality of the surface of the product and increase throughput. In this paper, we present several optical sensors developed in our Center which can be used for embedded surface metrology. We focus on the discussions of optical interferometry at a shop floor environment, which is normally subjected to environmental disturbances and vibrations. We will discuss the methods to reduce the influence of these noises and present the applications through case studies
Harbin Institute of Technology, China
Jinsong Leng is Cheung Kong Chair Professor, NSFC Outstanding Young Investigator and Founding Director of the Center for Smart Materials and Structures (CSMS) at Harbin Institute of Technology (HIT), China. He was also recognized as Research Giant of University of Southern Queensland (Australia) and Honorary Professor of Kingston University London (UK), and elected as a World Fellow of ICCM, and Fellow of the SPIE, Fellow of Institute of Physics (IOP), Fellow of Royal Aeronautical Society (RAeS), Fellow of Institute of Materials, Minerals, and Mining (IMMM) and Associate Fellow of AIAA. The research areas of Prof. Leng cover sensors and actuators, shape memory and electroactive polymers and their composites, multifunctional nanocomposites, active vibration control, structural health monitoring, and active deployable or morphing structures.
Speech title: Smart Composite Structures and Their Structural Health Monitoring: Recent Progress and Future Perspective
Abstract: Smart composites and structures have excellent performances, including self-monitoring, self-assembly, and adaptability, and show great potential in various fields. This talk will present some progress in structural health monitoring that utilizing Fiber Bragg Grating (FBG) and Mechanoluminescent (ML) sensors to monitor the temperature and strain during curing and service process of composites, as well as the large deformation of smart composites structures. Moreover, novel actuation methods and potential applications in deployable structures and 4D printing of shape memory polymers and their composites will be introduced. Finally, some challenges and perspective of smart composites and structures will be summarized.
Shanghai Institute of Optics and Fine Mechanics, China
Guohai Situ is a professor with the Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, holding a “1000 Talents Plan” professorship. Before he joined this institute in late 2012, he spent about 6 years working in University College Dublin in Ireland, Universität Stuttgart in Germany, and Princeton University in the United States, after he obtained his Ph. D degree from the Chinese Academy of Sciences in 2006. Dr. Situ's research interests span a wide field of computational optical imaging, ranging from developing novel techniques and algorithms for phase retrieval, to actively engineering the phase for computational optical imaging and optical signal processing. He has published 44 papers in leading journals including Nature Photonics. His papers have been cited over 2200 times according to Google Scholar. Dr. Situ is in the editorial boards of Scientific Reports, Advanced Optical Technologies, and Applied Optics.
Speech title: Computational Imaging: When Optics Meets Deep Learning
Abstract: In this presentation, I will talk about the applications of deep learning technique in the field of optical imaging. I will first introduce the basic concept of deep learning, and then talk about three use cases: i.e., how deep learning can be used for image reconstruction in computational ghost imaging, imaging through opaque wall, and digital holography.
Tianjin University, China
Dr. Chen Tang is currently a professor of the School of Electrical and Information Engineering, Tianjin University, China. She is the leader of five of research grant projects, including the National Natural Science Foundation of China, the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry, and so on. These papers have been published in Optics Letters, Optics Express, Applied Optics, Optics and Lasers in Engineering, IEEE Transactions on image processing and so on. Her research fields include: (1) Modern optical metrology technique; (2) Image processing and pattern recognition (multi-scale image feature extraction, image processing and recovery, object detection and recognition); (3) Research on optical image encryption; (4) Machine Learning and its application on data and image.
Speech title: An Advanced Method for Electronic Speckle Pattern Interferometry Fringes Images Based on Variational Image Decomposition
Abstract: Recently, the variational image decomposition (VID) methods have become an active research topic in image processing. In this report, we will introduce some applications of VID in electronic speckle pattern interferometry (ESPI) fringes images, mainly including: (1) a general filtering method for ESPI fringes images with various densities; (2) the estimation of fringe orientation and density for ESPI fringes images with greatly variable density; (3) the skeletonization of ESPI fringes images with greatly variable density. In our filtering method, a variable density ESPI fringes image was decomposed into low-density fringes, high-density fringes and noise. A low-density fringes image was decomposed into low-density fringes and noise. A high-density fringes image into high-density fringe and noise. We gave some suitable function spaces to describe low-density fringes, high-density fringes and noise, respectively. Then we constructed several models and numerical algorithms for ESPI fringe images with various densities. The estimation of fringe orientation and density from ESPI fringe images with greatly variable density is a challenging problem. We successfully decomposed an ESPI fringes image with greatly variable density into two images based on VID: one only included low-density fringes and the other high-density fringes. The density of the two decomposed images was uniform. The whole fringe orientation and density could be obtained by combining the corresponding results of the two decomposed images. The skeletonization of ESPI fringe images with greatly variable density is another challenging problem. The skeletonization methods based on gradient vector fields (GVFs) have been a powerful tool for ESPI fringes images. In the proposed method, the GVFs of low-density regions and the high-density regions were calculated respectively. The GVFs of a whole image were the sum of the decomposed GVFs of low-density regions and high-density regions. The skeletons of ESPI fringes images with variable density could be obtained based on the topological analysis of the GVFs of a whole image.
Tsinghua University, China
Dr. Xide Li is a professor in the Department of Engineering Mechanics at Tsinghua University. He received his B.Sc degree from the Department of Physics of Northwest University at Xi’an in 1986 and his M. Sc and Ph.D degrees in Engineering Mechanics in 1989 and in Mechanical Engineering in 1992, respectively, from Xi’an Jiaotong University. He was a guest researcher at Luleå University of Technology in Sweden in 1997 and Hong Kong University in 2000, and 2002 respectively. From 1993 to 1998, he was a postdoctoral research fellow and an associate professor at University of Science and Technology of China. He joined Tsinghua University as an associate professor in 1999 and then promoted to a full professor. He is a member of a council of Chinese Society of Theoretical and Applied Mechanics (CSTAM), the member of OSA (Optical Society of America) and American Nano Society, Vice-president of Experimental Mechanics Committee of CSTAM, and the Secretary-General of Beijing Society of Theoretical and Applied Mechanics (BSTAM). Professor Li’s current research fields are Micro/Nanomechanics, Experimental mechanics, and Mechanics of structures and materials in aerospace. He has edited several special issues in the international Journals, and authored and co-authored more than 160 scientific and technical papers.
Speech title: Scanning Imaging and Restoration of Moving and Deformed Surfaces
Abstract: Optical imaging is a parallel imaging, which can instantaneously make the image of an object at the image plane. People can record images from static to millions of frames per second with a proper medium. Recently, for example, New Scientist has reported that a super-fast camera was capable of capturing a laser beam on its flight at a speed of 20 billion frames per second. Therefore, for optical imaging, even transient or ultrafast events can be imaged and recorded by a suitable optical system and mediums. However, as it is known, the spatial resolution of optical imaging is limited by the diffraction effect of light waves, which is about 0.2 microns for visible light. Obviously, such spatial resolution is not acceptable for imaging and measuring materials, structures or devices at micro/nano scale. With the development of scanning microscopy technology such as SEM, TEM and AFM, high spatial resolution imaging technology enables one to distinguish a static object or its displacement at subatomic scale. However, for several decades, an important issue around scanning imaging is how to achieve accurate and precise image of a moving and deformed object. Although one can realize dynamic imaging of moving or deformed objects with high-speed frame scanning, the sequential imaging characteristic of scanning imaging mode leads to the imaging of every point in an image at different time, that is, non-parallel imaging. Obviously, first, scanning imaging mode can only form a blurry image for a moving or deformed object. Second, direct use of these scanning images measuring the displacement of the moving or deformed object will lead to delay and distortion of the displacement at time scale, which in turn causes inaccurate characterization of the object's displacement and deformation. Here, we establish a new scanning imaging and restoration theory of moving and deformed objects. The scanning equation of electron beam of an SEM, the kinetic and deformed equation of the tested object, and the hypothesis of imaging intensity invariant before and after movement or deformation of the object are combined, and a convolutional restoration equation of original image and scanned image is established. The restoration images scanning from harmonic vibration and nonlinear deformation of tested object are completed and a time series algorithm is proposed to extract its motion and deformation parameters. We anticipate that this imaging and restoration theory will make the scanning imaging to use in in-situ dynamic measurement.
Harbin Institute of Technology, China
Zhengjun Liu is a professor in Department of Automatic Test and Control, Harbin Institute of Technology (HIT), China. He received his BS degree in 2002 from HIT, Harbin, China. He received his PhD degree there in 2007 from the Department of Physics, HIT. He was honored by the Program for New Century Excellent Talents in University (2012). He published 96 peer reviewed journal articles in the field of optics, 2 books, and 1 book chapter. The publications have been cited by others for over 1300 times and H-index of 27. He is a senior member of OSA and a member of IEEE. His current research interests include optical image processing, super resolution imaging, and diffraction imaging.
Speech title: The Application of Multi-Image Phase Retrieval in Diffraction Imaging
Abstract: Coherent diffraction imaging is a useful tool for lens-free and less system, in the X-ray regime or visible spectrum. It is proved that lens imaging is a general kind of diffraction, which can be depicted by the general fractional Fourier transform mathematically. The multi-image phase retrieval is presented for obtaining more accurate reconstruction pattern of light field. Here more intensity patterns are applied for wavefront retrieval. The performance of these algorithm is demonstrated by numerical simulation and experiment. Noise reduction technique is also considered for the algorithms. The coherence of light source is also checked in these imaging system. The measurement error analysis of these axial methods, such as axial position error and wavelength bias, is displayed for obtaining the high quality of result image. The impact of sampling condition on phase retrieval is also analyzed here.
Purdue University, USA
Dr. Song Zhang is an associate professor of mechanical engineering at Purdue University. He received his Ph.D. degree in mechanical engineering from Stony Brook University in 2005; spent three years at Harvard as a postdoctoral research fellow; and then worked at Iowa State University before joining Purdue in Jan 2015. Dr. Zhang has published over 100 journal articles; authored one book; edited one book; co-authored 7 book chapters; and owns 3 U.S. patents. 13 of his journal articles were selected as cover page highlights. Besides being extensively utilized in academia, the technologies he developed have been used by rock band Radiohead to create a music video House of Cards; and by the Zaftig Films to produce a movie Focus (II). He has won AIAA Best Paper Award, IEEE ROBIO Best Conference Paper Award, Best of SIGGRAPH Disney Emerging Technologies Award, the NSF CAREER award, Stony Brook University’s “40 under 40 Alumni Award”, Discovery in Mechanical Engineering Award, and College of Engineering Early Career Faculty Research Excellence Awards from Iowa State University and Purdue University. Due to his contributions to high-speed, high-resolution 3D imaging and optical information processing, he was elected as the fellow of SPIE-International Society for Optics and Photonics, and the senior status of Optical Society of America (OSA).
Speech title: High-Speed 3D Shape Measurement Techniques and Applications
Abstract: Advances in optical imaging and machine/computer vision have provided integrated smart sensing systems for the manufacturing industry; and advanced 3D imaging could have profound impact on numerous fields, with broader applications including manufacturing, biomedical engineering, homeland security, and entertainment. Our research addresses the challenges in high-speed, high-resolution 3D imaging. The digital binary defocusing methods coincide with the inherent operation mechanism of the digital-light-processing (DLP) technology, permitting tens of kHz 3D imaging speed at camera pixel spatial resolution. In this paper, I will discuss the superfast 3D optical sensing using binary focusing method and cover some of the applications that we have been exploring including cardiac mechanics, forensic science.
Wuhan University, China
Dr. Yajun Wang received his PhD degree from Iowa State University in 2013.12. After that he conducted research about high-accuracy optical surface measurement in the Institution of Machinery Manufacturing Technology, CAEP. Since 2017 he has been an associate professor in the State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University. Dr. Yajun Wang has published over 20 journal papers and co-authored two book chapters. He has received the Excellence Research Award from Iowa State University, and the major areas of his interests include 3D optical sensing, machine vision and related applications.
Speech title: Multi-Level Pattern Design And Optimization for High-Accuracy 3D Shape Measurement
Abstract: For 3D shape measurement, the speed and accuracy are the two most concerned features for lots of applications. Recently developed binary defocusing technique has demonstrated its capability for high-speed 3D measurement using 1-bit fringe patterns. Meanwhile, numerous research has also been conducted to improve its accuracy by modulating the binary patterns in spatial domain. However, these techniques still have limitations for the current achieved accuracy. Considering the scenarios that extremely high accuracy is required, a possible solution is to adopt multi-level patterns with modulation in both time and spatial domain. In this presentation, I will introduce our recent work about multi-level pattern design and optimization, including multi-level triangular pulse width modulation (TPWM) method, multi-level optimal pulse width modulation (OPWM) method and single-pattern realization strategy.
Jiangsu University, China
Dr. Houxiao Wang received his PhD degree from Nanyang Technological University (NTU) in 2013. He conducted the collaboration work attached with the Institute of High Performance Computing (IHPC) in Singapore from 2009 to 2011. He is currently an associate professor at the School of Mechanical Engineering, Jiangsu University. His current research interests mainly focus on the ultrasonic vibration-assisted laser processing/manufacturing, the advanced integrated magnetic-ultrasonic assisted laser processing/manufacturing, and the focused ion beam (FIB) nanofabrication and nanometrology for optical applications. Dr. Wang is currently the member of several professional organizations such as The Optical Society (OSA), the Optics and Photonics Society of Singapore (OPSS), and the Materials Research Society of Singapore (MRSS). He served as a session chair for Advanced Lasers and Applications of the 12th Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR 2017), the 22nd OptoElectronics and Communications Conference (OECC 2017), and the 5th Photonics Global Conference 2017 (PGC 2017), Singapore. He got the NTU Research Scholarship (Singapore) in 2008, and he is currently a core member of Innovation/Enterpreneurship Team supported by the Innovation & Enterpreneurship Project of Jiangsu Province.
Speech title: Magnetic-Ultrasonic Assisted Laser Drilling and Trepanning
Abstract: Electro-discharge machining (EDM) and pulsed laser drilling/trepanning are commonly used for fabricating cooling holes in nickel super-alloy aero-engine components. Although the EDM technique produces high quality holes, it is very slow, without mentioning the high tooling cost. The millisecond pulsed laser drilling/trepanning is much faster. However, the laser (especially a laser with millisecond pulses) alone usually cannot drill/trepan high quality microholes, mainly resulting from the normally encountered recast layer formation with metallurgical/morphological defects. In this talk, a magnetic-ultrasonic assisted laser drilling/trepanning technique is accordingly reported for machining microholes in GH4037 nickel super-alloy. The mechanism of this advanced technique will be introduced. Moreover, the effects of the ultrasonic-magnetic-laser parameters on the millisecond pulsed Nd:YAG laser drilling/trepanning performance and quality will be also reported through comparing with holes drilled/trepanned without ultrasonic-magnetic assistance.
University of Nottingham, UK
Richard is currently a professor in metrology at the University of Nottingham and prior to this spent 25 years at the National Physical Laboratory. Richard's research is dominated by what he calls "information-rich metrology": the enhancement of manufacturing metrology through the use of a priori information, often utilising concepts from artificial intelligence. His current interests are the dimensional measurement of precision and additive manufactured structures. Richard is on the Council of the European Society of Precision Engineering and Nanotechnology, the International Committee on Measurements and Instrumentation and several international standards committees. He is the European Editor-in-Chief for Precision Engineering. He has over 350 publications including five textbooks. He is a Fellow of the Institute of Physics, the Institution of Engineering & Technology, the International Society of Nanomanufacturing and a Sustaining Member of the American Society of Precision Engineering. He is a visiting professor at Loughborough University and the Harbin Institute of Technology.
Speech title: Enhancing Freeform Shape Measurement Using Artificial Intelligence
Abstract: There is increasing demand for quality assurance of highly-complex objects, for example, those produced using additive manufacturing. A priori information about the nominal geometry of the measured object and the operating principles of measurement techniques can used along with multi-sensor data fusion to improve system performance in terms of object coverage. More specifically, we present a surface form measurement system which uses artificial intelligence and machine vision to enable the efficient combination of fringe projection, photogrammetry and deflectometry, can identify the regions of an object that are optimally measured by each individual process, and employs a measurement strategy in which the measurement systems are combined in concert to achieve a complete three-dimensional measurement of the object. Three-dimensional data is acquired on multiple scales at high speeds whilst the system minimises the size of the dataset required to perform the measurement. The system has a target maximum permissible error of 50 μm and the prototype demonstrates the ability to measure complex geometries of additively manufactured objects, with a maximum size of (10 × 10 × 10) cm, with minimal user input.
Beijing University of Posts and Telecommunications, China
Xinzhu Sang is a professor of the State Key Laboratory of Information Photonics and Optical Communications at Beijing University of Posts and Telecommunications. His current research interests include three-dimensional display, holography and novel photonic devices. He has published more than 160 pre-reviewed research papers in scientific journals, and holds 25 patents. He received dual bachelor's degrees in instrument science and management engineering from Tianjin University in 1999, and the Ph.D. degree at Beijing University of Posts and Telecommunications in 2005.From December 2003 to March 2005, he was with Optoelectronics Research Centre, Department of Electronic Engineering, City University of Hong Kong as a research assistant. From July 2007 to July 2008, he worked in University of California at Irvine as a postdoctoral research scholar. He has been a full professor in Beijing University of Posts and Telecommunications since September 2012. He is the deputy director and the secretary-general of the committee of Holography and Optical information, Chinese Optical Society Processing, a vice director of VR/AR division of Chinese Institute of Electronics. In 2011, he was selected for the Program for New Century Excellent Talents in University, Beijing Nova Program of Science and Technology. He was awarded as "Beijing Outstanding Teacher" prize in 2017.
Speech title: Interactive 3D Light-Field Displays with Real Captured 3D Data
Abstract: From Human visual characteristics, required performances and parameters of the 3D light-field display are discussed. A review of three-dimensional (3D) light filed displays is presented, and large size 3D light-field displays in BUPT are specially discussed. With the holographic functional screen and the compound lens array, an interactive floating full-parallax 3D light-field display is demonstrated based on a 27 inch 5120×2880 liquid-crystal panel. To suppress the aberration and increase the viewing angle, a compound-lens-array with two pieces of lens in each lens unit is designed and fabricated. The optimally designed holographic functional screen is used to re-modulate the light distribution from the lens-array, and only the clear 3D light field image is perceived without seeing the lens array. The floating full-parallax 3D light-field image with clear displayed depth of 30 cm can be perceived with the right geometric occlusion and smooth parallax in the viewing angle of 45°, where 96 ×96 views are used to generate the coded light-field image. The real-time interactive full-parallax 3D light-field display with the frame rate of 30 fps is realized. The functions of the holographic functional screen and the complex lens array are resolved and integrated in a thin optical devices, the full-parallax 3D light field display with the view angel above 80°and acceptable resolution is demonstrated. Based on the backward ray tracing coding, the real-time rendering for the light field display is realized. Touchable floating 3D image light-field displays in the air all also demonstrated. Interactive scientific 3D displays with the data of little creatures acquired by the full-color structured illumination optical sectioning microscopy are provided.
Tsinghua University, China
Liangcai Cao received his BS/MS and PhD degree from Harbin Institute of Technology and Tsinghua University, in 1999/2001 and 2005, respectively. Then he became an assistant professor at Department of Precision Instruments, Tsinghua University. He is now a tenured associate professor and serving as the director of Institute of Opto-Electronic Engineering at Tsinghua University. He was a visiting scholar at UC Santa Cruz and MIT in 2009 and 2014, respectively. His current research interests are information storage, processing and display based on holography. He is a senior member of OSA and SPIE.
Speech title: A Fast Algorithm for Compressive Digital Holography
Abstract: In-line lensless holography could maintain high space-bandwidth product (SBP) without an imaging lens, compared with off-axis holography. Compressive holography (CH) which combines compressive sensing and in-line lensless holography is considered as a promising solution for high SBP three-dimensional imaging. We developed a high SBP three-dimensional imaging algorithm based on the total-variation sparsity constraint. An efficient block-wise CH algorithm is used to reduce the digital holographic reconstruction time. The block-wise algorithm could locate accurate reconstruction searching spaces, resulting in high convergence speed and improved image contrast..