Imaging|4 Article(s)
Detection and upconversion of three-dimensional MMW/THz images to the visible
Avihai Aharon (Akram), Daniel Rozban, Avi Klein, Amir Abramovich, Yitzhak Yitzhaky, and Natan S. Kopeika
We present an inexpensive technique to obtain a three-dimensional (3D) millimeter wave (MMW) and terahertz (THz) image using upconversion. In this work we describe and demonstrate a method for upconversion of MMW/THz radiation to the visual band using a very inexpensive miniature glow discharge detector (GDD) and a silicon photodetector. We present MMW/THz upconversion images based on measuring the visual light emitting from the GDD rather than its electrical current. The results show better response time and better sensitivity compared to the electronic detection performed previously. Furthermore, in this work we perform frequency modulation continuous wave (FMCW) radar detection based on this method using a GDD lamp, with a photodetector to measure GDD light emission. By using FMCW detection, the range in addition to the intensity at each pixel can be obtained, thus yielding the 3D image. The GDD acts as a heterodyne mixer not only electronically but also optically. Thesuggested 3D upconversion technique using the GDD is simple and inexpensive and has better performance compared to other MMW/THz imaging systems suggested in the literature. This method provides minimum detectable signal power that is about 6 orders of magnitude better than similar plasma systems due to the very largeinternal signal gain deriving from the much smaller electrode separation and resulting in much higher plasma electric field. We present an inexpensive technique to obtain a three-dimensional (3D) millimeter wave (MMW) and terahertz (THz) image using upconversion. In this work we describe and demonstrate a method for upconversion of MMW/THz radiation to the visual band using a very inexpensive miniature glow discharge detector (GDD) and a silicon photodetector. We present MMW/THz upconversion images based on measuring the visual light emitting from the GDD rather than its electrical current. The results show better response time and better sensitivity compared to the electronic detection performed previously. Furthermore, in this work we perform frequency modulation continuous wave (FMCW) radar detection based on this method using a GDD lamp, with a photodetector to measure GDD light emission. By using FMCW detection, the range in addition to the intensity at each pixel can be obtained, thus yielding the 3D image. The GDD acts as a heterodyne mixer not only electronically but also optically. Thesuggested 3D upconversion technique using the GDD is simple and inexpensive and has better performance compared to other MMW/THz imaging systems suggested in the literature. This method provides minimum detectable signal power that is about 6 orders of magnitude better than similar plasma systems due to the very largeinternal signal gain deriving from the much smaller electrode separation and resulting in much higher plasma electric field.
Photonics Research
- Publication Date: Dec. 23, 2016
- Vol. 4, Issue 6, 06000306 (2016)
Scalar-matrix-structured ghost imaging
Chao Yang, Chenglong Wang, Jian Guan, Chi Zhang, Shuxu Guo, Wenlin Gong, and Fengli Gao
The features of the characteristic matrix used in linear intensity correlation reconstruction methods are directly related to the quality of ghost imaging. In order to suppress the noise caused by the off-diagonal elements in the characteristic matrix, we propose a reconstruction method for ghost imaging called scalar-matrix-structured ghost imaging (SMGI). The characteristic matrix is made to approximate a scalar matrix by modifying the measurement matrix. Experimental results show that SMGI improves the peak signal-to-noise ratio of the object reconstruction significantly compared with differential ghost imaging, even in the case of a nonzero two-arm longitudinal difference, which is a promising result for practical applications.of China (2013AA122901); National Natural Science Foundation of China (NSFC) (61571427); Youth Innovation Promotion Association of the Chinese Academy of Sciences (2013162). The features of the characteristic matrix used in linear intensity correlation reconstruction methods are directly related to the quality of ghost imaging. In order to suppress the noise caused by the off-diagonal elements in the characteristic matrix, we propose a reconstruction method for ghost imaging called scalar-matrix-structured ghost imaging (SMGI). The characteristic matrix is made to approximate a scalar matrix by modifying the measurement matrix. Experimental results show that SMGI improves the peak signal-to-noise ratio of the object reconstruction significantly compared with differential ghost imaging, even in the case of a nonzero two-arm longitudinal difference, which is a promising result for practical applications.of China (2013AA122901); National Natural Science Foundation of China (NSFC) (61571427); Youth Innovation Promotion Association of the Chinese Academy of Sciences (2013162).
Photonics Research
- Publication Date: Dec. 23, 2016
- Vol. 4, Issue 6, 06000281 (2016)
Cross-talk-free integral imaging three-dimensional display based on a pyramid pinhole array
Huan Deng, Qiong-Hua Wang, Fei Wu, Cheng-Gao Luo, and Yao Liu
We propose a cross-talk-free integral imaging 3D display based on a pyramid pinhole array. The pyramid pinhole array is used to provide a point light source array. Since the generated point light source array is behind a transmission-type display panel that displays an elemental image array, the pseudoscopic problem can be resolved. By setting the appropriate parameters for the pyramid pinhole array, the cross talk can be eliminated. We experimentally verify the reconstruction of the orthoscopic and cross-talk-free 3D images using the proposed 3D display. We propose a cross-talk-free integral imaging 3D display based on a pyramid pinhole array. The pyramid pinhole array is used to provide a point light source array. Since the generated point light source array is behind a transmission-type display panel that displays an elemental image array, the pseudoscopic problem can be resolved. By setting the appropriate parameters for the pyramid pinhole array, the cross talk can be eliminated. We experimentally verify the reconstruction of the orthoscopic and cross-talk-free 3D images using the proposed 3D display.
Photonics Research
- Publication Date: Jun. 18, 2015
- Vol. 3, Issue 4, 04000173 (2015)
Ghost imaging for an axially moving target with an unknown constant speed
Xiaohui Li, Chenjin Deng, Mingliang Chen, Wenlin Gong, and Shensheng Han
The influence of the axial relative motion between the target and the source on ghost imaging (GI) is investigated. Both the analytical and experimental results show that the transverse resolution of GI is reduced as the deviation of the target’s center position from the optical axis or the axial motion range increases. To overcome the motion blur, we propose a deblurring method based on speckle-resizing and speed retrieval, and we experimentally validate its effectiveness for an axially moving target with an unknown constant speed. The results demonstrated here will be very useful to forward-looking GI remote sensing.imaging;Image analysis The influence of the axial relative motion between the target and the source on ghost imaging (GI) is investigated. Both the analytical and experimental results show that the transverse resolution of GI is reduced as the deviation of the target’s center position from the optical axis or the axial motion range increases. To overcome the motion blur, we propose a deblurring method based on speckle-resizing and speed retrieval, and we experimentally validate its effectiveness for an axially moving target with an unknown constant speed. The results demonstrated here will be very useful to forward-looking GI remote sensing.imaging;Image analysis
Photonics Research
- Publication Date: Jun. 12, 2015
- Vol. 3, Issue 4, 04000153 (2015)
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