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https://www.readbyqxmd.com/read/28437983/generation-of-patterned-phase-only-holograms-ppohs
#1
P W M Tsang, Y T Chow, T-C Poon
A fast and non-iterative method for generating a phase-only hologram, hereafter referred to as the patterned-phase-only hologram (PPOH), is reported in this paper. Briefly, a phase mask with a periodic phase pattern is added to the source image, and converted into a hologram. Subsequently, only the phase component is retained as a phase-only hologram. Experimental evaluation reveals that the visual quality of the reconstructed images of the PPOH generated with our proposed method is favorable, and superior to that obtained with existing methods...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437967/design-of-see-through-near-eye-display-for-presbyopia
#2
Yishi Wu, Chao Ping Chen, Lei Zhou, Yang Li, Bing Yu, Huayi Jin
We propose a compact design of see-through near-eye display that is dedicated to presbyopia. Our solution is characterized by a plano-convex waveguide, which is essentially an integration of a corrective lens and two volume holograms. Its design rules are set forth in detail, followed by the results and discussion regarding the diffraction efficiency, field of view, modulation transfer function, distortion, and simulated imaging.
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28430252/measuring-spatiotemporal-ultrafast-field-structures-of-pulses-from-multimode-optical-fibers
#3
Zhe Guang, Michelle Rhodes, Rick Trebino
Ultrashort pulses emerging from multimode optical fibers are spatiotemporally complex, because inside these fibers the modes have different spatial intensity patterns and experience different propagation velocities and dispersions. To determine the spatiotemporal field from multimode fibers, we applied a technique for the complete measurement of the output pulses called a spatially and temporally resolved intensity and phase evaluation device: full information from a single hologram. It yields the complete electric field over space and time from multiple digital holograms, simultaneously recorded at different frequencies on a single camera frame...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28430234/dimensional-properties-of-laguerre-gaussian-vortex-beams
#4
Jie Zhang, Su-Juan Huang, Fu-Quan Zhu, Wei Shao, Mu-Sheng Chen
We derive and analyze the dimensional properties of Laguerre-Gaussian vortex beams theoretically and numerically. The analytical expressions of inner and outer radii are given out and proved to be proportional to the transverse beam size, when the topological charge remains. The ratio of the outer and inner radius only depends on the topological charge, having nothing to do with the waist radius and the propagation distance, and the ratio decreases as the topological charge increases. Using a spatial light modulator loaded with computer-generated holograms, we generate vortex beams...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28381036/programmable-cgh-on-photochromic-plates-coded-with-dmd-generated-masks
#5
R Alata, G Pariani, F Zamkotsian, P Lanzoni, A Bianco, C Bertarelli
Computer Generated Holograms (CGHs) are used for wavefront shaping and complex optics testing. Present technology allows for recording binary CGHs. We propose a Digital Micro-mirror Device (DMD) as a reconfigurable mask, to record rewritable binary and grayscale CGHs on a photochromic plate. Opaque at rest, this plate becomes transparent when it is illuminated with visible light of suitable wavelength. We have successfully recorded the very first amplitude grayscale CGH, with a contrast greater than 50, which was reconstructed with a high fidelity in shape, intensity, size and location...
March 20, 2017: Optics Express
https://www.readbyqxmd.com/read/28381004/speckle-reduced-lensless-holographic-projection-from-phase-only-computer-generated-hologram
#6
Chenliang Chang, Yijun Qi, Jun Wu, Jun Xia, Shouping Nie
This paper presents a method for the implementation of speckle reduced lensless holographic projection based on phase-only computer-generated hologram (CGH). The CGH is calculated from the image by double-step Fresnel diffraction. A virtual convergence light is imposed to the image to ensure the focusing of its wavefront to the virtual plane, which is established between the image and the hologram plane. The speckle noise is reduced due to the reconstruction of the complex amplitude of the image via a lensless optical filtering system...
March 20, 2017: Optics Express
https://www.readbyqxmd.com/read/28380970/single-shot-digital-holographic-microscopy-with-a-modified-lateral-shearing-interferometer-based-on-computational-telecentricity
#7
Byung-Mok Kim, Seong-Jin Park, Eun-Soo Kim
Single-shot digital holographic microscopy (SS-DHM) with a modified lateral-shearing interferometer (MLSI) based on computational telecentricity is proposed. The proposed system is composed of three-step processes such as optical recording, digital compensation and numerical reconstruction processes. In the 1st step, the object beam is optically recorded with the MLSI, where a tube lens is set to be located at the slightly shorter distance than its focal length from the objective lens. Then, another phase factor due to the deviated locating of the tube lens from its focal length is additionally generated, which is called an additional quadratic phase factor (AQPF)...
March 20, 2017: Optics Express
https://www.readbyqxmd.com/read/28380953/compact-see-through-3d-head-mounted-display-based-on-wavefront-modulation-with-holographic-grating-filter
#8
Qiankun Gao, Juan Liu, Xinhui Duan, Tao Zhao, Xin Li, Peilin Liu
A compact see-through three-dimensional head-mounted display (3D-HMD) is proposed and investigated in this paper. Two phase holograms are analytically extracted from the object wavefront and uploaded on different zones of the spatial light modulator (SLM). A holographic grating is further used as the frequency filter to couple the separated holograms together for wavefront modulation. The developed preliminary prototype has a simple optical facility and a compact structure (133.8mm × 40.4mm × 35.4mm with a 47...
April 3, 2017: Optics Express
https://www.readbyqxmd.com/read/28380937/digital-adaptive-optics-confocal-microscopy-based-on-iterative-retrieval-of-optical-aberration-from-a-guidestar-hologram
#9
Changgeng Liu, Damber Thapa, Xincheng Yao
Guidestar hologram based digital adaptive optics (DAO) is one recently emerging active imaging modality. It records each complex distorted line field reflected or scattered from the sample by an off-axis digital hologram, measures the optical aberration from a separate off-axis digital guidestar hologram, and removes the optical aberration from the distorted line fields by numerical processing. In previously demonstrated DAO systems, the optical aberration was directly retrieved from the guidestar hologram by taking its Fourier transform and extracting the phase term...
April 3, 2017: Optics Express
https://www.readbyqxmd.com/read/28380936/experimental-study-on-optical-image-encryption-with-asymmetric-double-random-phase-and-computer-generated-hologram
#10
Sixing Xi, Xiaolei Wang, Lipei Song, Zhuqing Zhu, Bowen Zhu, Shuai Huang, Nana Yu, Huaying Wang
Optical image encryption, especially double-random-phase-based, is of great interest in information security. In this work, we experimentally demonstrate the security and feasibility of optical image encryption with asymmetric double random phase and computer-generated hologram (CGH) by using spatial light modulator. First of all, the encrypted image modulated by asymmetric double random phase is numerically encoded into real-value CGH. Then, the encoded real-value CGH is loaded on the spatial light modulator and optically decrypted in self-designed experimental system...
April 3, 2017: Optics Express
https://www.readbyqxmd.com/read/28380853/fiber-based-lensless-polarization-holography-for-measuring-jones-matrix-parameters-of-polarization-sensitive-materials
#11
Xuan Liu, Yang Yang, Lu Han, Cheng-Shan Guo
We report a fiber-based lensless holographic imaging system to realize a single-shot measurement of two dimensional (2-D) Jones matrix parameters of polarization-sensitive materials. In this system, a multi-source lensless off-axis Fresnel holographic recording geometry is adopted, and two optical fiber splitters are used to generate the multiple reference and illumination beams required for recording a four-channel angular-multiplexing polarization hologram (AMPH). Using this system and the method described in this paper, spatially resolved Jones matrix parameters of a polarization-sensitive material can be retrieved from one single-shot AMPH...
April 3, 2017: Optics Express
https://www.readbyqxmd.com/read/28377343/-three-dimensional-morphology-of-c6-36-cells-infected-by-dengue-virus-a-study-based-on-digital-holographic-microscopy
#12
Jian-Hai Yu, Xu-Ling Liu, Yu-Jing Liu, Xiao-En He, Yuan Hui, Bao Zhang, Li Zhu, Wei Zhao
OBJECTIVE: To monitor the 3-dimensional (3D) morphological changes of C6/36 cells during dengue virus (DENV) infection using a live-cell imaging technique based on digital holographic microscopy and provide clues for better understanding the mechanisms of DENV infection. METHODS: C6/36 cells were seeded in 6-well plates to determine the optimal imaging density under a holographic cell imager, and the morphological changes of the cells were recorded in response to a culture temperature change from 28 degrees celsius; to 37 degrees celsius; C6/36 cells were infected with 4 DENV strains with different serotypes at 28 degrees celsius; and incubated at 37 degrees celsius; for 24 h, and the 3D holograms and relevant morphological parameters were recorded at different time points using HoloMonitor M4 holographic cell imaging and analysis system...
March 20, 2017: Nan Fang Yi Ke da Xue Xue Bao, Journal of Southern Medical University
https://www.readbyqxmd.com/read/28375388/asic-chipset-design-to-generate-block-based-complex-holographic-video
#13
Young-Ho Seo, Yoon-Hyuk Lee, Dong-Wook Kim
In this paper, we propose a new hardware architecture implemented as a very large scaled integrated circuit by using an application-specific integrated circuit technology, where block-based calculations are used to generate holograms. The proposed hardware is structured to produce a part of a hologram in the block units in parallel. A block of a hologram is calculated using an object point, and then the calculation is repeated for all object points to obtain intermediate results that are accumulated to produce the final block of a hologram...
March 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28375380/compact-and-field-portable-3d-printed-shearing-digital-holographic-microscope-for-automated-cell-identification
#14
Siddharth Rawat, Satoru Komatsu, Adam Markman, Arun Anand, Bahram Javidi
We propose a low-cost, compact, and field-portable 3D printed holographic microscope for automated cell identification based on a common path shearing interferometer setup. Once a hologram is captured from the portable setup, a 3D reconstructed height profile of the cell is created. We extract several morphological cell features from the reconstructed 3D height profiles, including mean physical cell thickness, coefficient of variation, optical volume (OV) of the cell, projected area of the cell (PA), ratio of PA to OV, cell thickness kurtosis, cell thickness skewness, and the dry mass of the cell for identification using the random forest (RF) classifier...
March 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28375313/comparison-of-diffraction-patterns-exposed-by-pulsed-and-cw-lasers-on-positive-tone-photoresist
#15
Ramūnas Bakanas, Virginija Jankauskaitė, Andrejs Bulanovs, Stanislovas Zacharovas, Andrius Vilkauskas
Two different grating formation geometries for recording onto the positive-tone photoresist with pulsed laser and continuous-wave sources are analyzed and compared. Diffraction efficiency measurements and atomic force microscopy (AFM) examination have been performed in order to investigate the optical and topographical properties of the recorded structures. Gratings patterned by a continuous-wave laser and by a pulsed laser working in the single pulse and multipulse regimes showed different surface roughness and optical properties...
March 10, 2017: Applied Optics
https://www.readbyqxmd.com/read/28368630/metasurface-polarization-optics-independent-phase-control-of-arbitrary-orthogonal-states-of-polarization
#16
J P Balthasar Mueller, Noah A Rubin, Robert C Devlin, Benedikt Groever, Federico Capasso
We present a method allowing for the imposition of two independent and arbitrary phase profiles on any pair of orthogonal states of polarization-linear, circular, or elliptical-relying only on simple, linearly birefringent wave plate elements arranged into metasurfaces. This stands in contrast to previous designs which could only address orthogonal linear, and to a limited extent, circular polarizations. Using this approach, we demonstrate chiral holograms characterized by fully independent far fields for each circular polarization and elliptical polarization beam splitters, both in the visible...
March 17, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28362773/dual-channel-recording-based-on-the-null-reconstruction-effect-of-orthogonal-linear-polarization-holography
#17
Jinliang Zang, Guoguo Kang, Peng Li, Ying Liu, Fenglan Fan, Yifan Hong, Yong Huang, Xiaodi Tan, An'an Wu, Tsutomu Shimura, Kazuo Kuroda
We report on dual-channel recording within polarization holography written by orthogonal linear polarization waves. The null reconstruction effect (NRE) of linear polarization holography was experimentally achieved at a large cross-angle of π/2 inside the polarization-sensitive media. Based on the NRE, two polarization encoded holograms were recorded in a dual-channel recording system with negligible inter-channel crosstalk. The two polarization multiplexed holograms could then be sequentially or simultaneously readout by shifting the polarization state of reference wave with the best signal-to-noise of 18:1 obtained within the experiment...
April 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28362758/electro-holographic-display-using-a-zblan-glass-as-the-image-space
#18
Jung-Young Son, Hyoung Lee, Jina Byeon, Jiangbo Zhao, Heike Ebendorff-Heidepriem
An Er<sup>3+</sup>-doped ZBLAN glass is used to display a 360° viewable reconstructed image from a hologram on a DMD. The reconstructed image, when the hologram is illuminated by a 852 nm wavelength laser beam, is situated at the inside of the glass, and then a 1530 nm wavelength laser beam is crossed through the image to light it with an upconversion green light, which is viewable at all surrounding directions. This enables us to eliminate the limitation of the viewing zone angle imposed by the finite size of pixels in electro-holographic displays based on digital display chips/panels...
April 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28295088/reduction-of-speckle-noise-in-holographic-images-using-spatial-jittering-in-numerical-reconstructions
#19
Mohamed Haouat, Jorge Garcia-Sucerquia, Abdelhamid Kellou, Pascal Picart
This Letter presents an easy, fast, and efficient single-shot method to reduce speckle noise in digital Fresnel holography. In this method, several images from a single hologram are reconstructed by introducing spatial displacements in the Fresnel kernel. Spatial jitters produce images with different speckle positions. Averaging the set of numerically produced images leads to a strong reduction of speckle noise in both amplitude and phase difference images. The experimental results show the suitability of the proposed approach and confirm its applicability to digital holographic interferometry...
March 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28269466/heart-activity-monitoring-using-3d-hologram-based-on-smartphone
#20
Tharoeun Thap, Heewon Chung, Jinseok Lee
In this paper, we used smartphone to obtained pulsatile signal from a fingertip by illuminating the skin tissue using flashlight and with an on-board camera to record the change of the light intensity reflected from the tissue. The pulsatile signal is produced by analyzing average green component values of the frames taken by the camera and the heart rate is estimated in real time by detecting the pulse peaks. Based on each instant obtained heartbeat, we design a heart animation that beats according to each interval of the heartbeat...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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