2015
2015
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Record 205 of
Title:Exposure time control of large aperture static imaging spectrometer
Author(s):Yang, Yang(1,2); Liu, Xue-Bin(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 44 Issue: 11 DOI: 10.3788/gzxb20154411.1123004 Published: November 1, 2015Abstract:The method of CCD exposure time control based on driver timing was proposed for the situation of the high performance CCD imaging detector without electronic shutter. The charge will be drained quickly in the excess period by increasing the charge excretion state after the horizental readout under the certain frame frequency. It can control the CCD exposure time effectively, and overcome the problem the CCD minimum exposure time is equal to the readout time. Results show that the booming resistance of the large aperture static imaging spectrometer is well improved and the non-linearity of the method is 4.61%. ? 2015, Chinese Optical Society. All right reserved.Accession Number: 20155101686148 -
Record 206 of
Title:Analysis of vertical axis error of vehicular theodolite
Author(s):Jiang, Bo(1,2); Zhou, Sizhong(1); Jiang, Kai(1); Fu, Huaiyang(1,2); Mei, Chao(1,2)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 44 Issue: 5 DOI: Published: May 25, 2015Abstract:The theodolite which works on a vehicle has measurement error caused by the deformation of vehicle platform. Two methods that the single error accumulation method and the comprehensive coordinate transformation method to compensate the error were deduced. First, the basic principle of the two methods was analyzed, taking into account the limitations of the different correction methods. Then a practical example with a vehicle platform containing large deformation derivation was built. The measurement error were summarized in two correction methods were compared. The results show that the correct error of the single error accumulation method has several points within large error in whole work scope of the theodolite, caused the error about 5″ larger than the comprehensive coordinate transform method. Therefore the comprehensive coordinate transformation method must be used to obtain high- precision measurements. ?, 2015, Chinese Society of Astronautics. All right reserved.Accession Number: 20153501209550 -
Record 207 of
Title:A new designed impedance matching circuit used for gated framing camera
Author(s):Zhu, Bingli(1); Bai, Xiaohong(1); Bai, Yonglin(1); Gou, Yongsheng(1); Liu, Baiyu(1); Wang, Bo(1); Qin, Junjun(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9449 Issue: DOI: 10.1117/12.2077094 Published: 2015Abstract:Framing camera based on gated Micro-channel plate (MCP) was widely used in inertial confinement fusion (ICF) and Z-pinch because of its ultrafast time-resolve. Electrons with imaging information are multiplied when the HV pulse propagating through the MCP strip line. Obviously, the HV pulse was used as a shutter here, then the exposure time of the imagine will be determined by the width of the pulse. Theoretical analysis indicates that thegating pulse(200ps) has a bandwidth of 5GHz, thus, impedance match in the propagating path of the pulse will be very important. Impedance mismatch will cause reflecting of the pulse and decrease the transmission efficiency. This will cause un-uniformity of the dynamic gain of the MCP, and finally resulting in imagedistortion. A new designed impedance matching circuit is developed in this paper. Simulated results showedthatthe newdesignedimpedance matching circuit couldreduce the reflection of thegating pulse significantly, and dynamicgain uniformity of the MCP was increased simultaneously. ? 2015 SPIE.Accession Number: 20151100635557 -
Record 208 of
Title:Design of multi-spectral images real-time segmentation system
Author(s):Zhai, Bo(1); Qu, Youshan(1); Han, Yameng(1); Zhou, Jiang(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9449 Issue: DOI: 10.1117/12.2075966 Published: 2015Abstract:In order to realize the real-time segmentation processing of multi spectral images in practice, a real-time multi-spectral images segmentation system composed of four TMS320C6455 DSPs, two Virtex-41/4V4 XC4VLX801/4FPGAs and one Virtex-2 Pro1/4V2 Pro201/4FPGA is designed. Through the optimization of the cooperation processing of the multi DSP and multi FPGA, the parallel multitask processing ability of the DSPs and the effective interface coordination ability of the FPGAs in the built system are used fully. In order to display the processing ability, the segmentation test experiments of 10 spectra visible images, with 1024×1024, segmented by the Multi-scale Image Segmentation Method, was done in the built multi spectral images segment system. The experiment results prove that the multi DSP and multi FPGA multi spectral images processing system designed in this paper satisfies the real-time processing requirement in engineering practice. ? 2015 SPIE.Accession Number: 20151100635577 -
Record 209 of
Title:Graded index porous optical fibers - dispersion management in terahertz range
Author(s):Ma, Tian(1,2); Markov, Andrey(1); Wang, Lili(2); Skorobogatiy, Maksim(1)Source: CLEO: Applications and Technology, CLEO-AT 2015 Volume: Issue: DOI: 10.1364/CLEO_AT.2015.JW2A.56 Published: May 4, 2015Abstract:Graded index porous fiber incorporating an air-hole array featuring variable air-hole diameters and inter-hole separations is proposed. We experimentally demonstrate smaller pulse distortion, larger bandwidth and higher excitation efficiency compared to fibers with uniform porosity. ? 2015 OSA.Accession Number: 20152701008434 -
Record 210 of
Title:Vibrational phase imaging in wide-field CARS for nonresonant background suppression
Author(s):Zheng, Juanjuan(1,3); Akimov, Denis(1); Heuke, Sandro(1); Schmitt, Michael(1,2); Yao, Baoli(3); Ye, Tong(4); Lei, Ming(3); Gao, Peng(3); Popp, Jürgen(1,2)Source: Optics Express Volume: 23 Issue: 8 DOI: 10.1364/OE.23.010756 Published: 2015Abstract:Coherent Anti-Stokes Raman Scattering (CARS) microscopy is a valuable tool for label-free imaging of biological samples. As a major drawback quantification based on CARS images is compromised by the appearance of a nonresonant background. In this paper we propose and demonstrate a wide-field CARS vibrational phase imaging scheme that allows for nonresonant background suppression. Several CARS images at a few consecutive planes perpendicular to the propagation direction were recorded to reconstruct a phase map utilizing the iteration phase retrieval method. Experimental results verify that the CARS background is efficiently suppressed by the phase imaging approach, as compared to traditional CARS imaging without background correction. The proposed background correction method is robust against environmental disturbance, since the experimental implementation of the suggested detection scheme requires no reference beam. ? 2015 Optical Society of America.Accession Number: 20154901641205 -
Record 211 of
Title:High-power Ho:YAG laser wing-pumped by a Tm:fiber laser at 1933 nm
Author(s):Zhao, T.(1); Wang, F.(2,3); Shen, D.Y.(1)Source: Applied Optics Volume: 54 Issue: 7 DOI: 10.1364/AO.54.001594 Published: March 1, 2015Abstract:We report on the high-power and efficient operation of a Ho:YAG laser wing-band-pumped by a Tm:fiber laser at 1933 nm. Using an output coupler of 10% transmission, maximum continuous-wave (CW) output power of 24.2 W at 2124 nm was generated under 42.6 W of absorbed pump power, corresponding to slope efficiency with respect to absorbed pump power of 57.6%. The operating wavelength of the Ho:YAG laser centered at 2092 or 2124 nm depending on different resonator designs. Prospects for further improvement in laser performance with this wing-pump configuration are discussed. ? 2015 Optical Society of America.Accession Number: 20153801287490 -
Record 212 of
Title:A design of camera simulator for photoelectric image acquisition system
Author(s):Cai, Guanghui(1,2); Liu, Wen(1); Zhang, Xin(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9449 Issue: DOI: 10.1117/12.2075572 Published: 2015Abstract:In the process of developing the photoelectric image acquisition equipment, it needs to verify the function and performance. In order to make the photoelectric device recall the image data formerly in the process of debugging and testing, a design scheme of the camera simulator is presented. In this system, with FPGA as the control core, the image data is saved in NAND flash trough USB2.0 bus. Due to the access rate of the NAND, flash is too slow to meet the requirement of the sytsem, to fix the problem, the pipeline technique and the High-Band-Buses technique are applied in the design to improve the storage rate. It reads image data out from flash in the control logic of FPGA and output separately from three different interface of Camera Link, LVDS and PAL, which can provide image data for photoelectric image acquisition equipment?s debugging and algorithm validation. However, because the standard of PAL image resolution is 720?576, the resolution is different between PAL image and input image, so the image can be output after the resolution conversion. The experimental results demonstrate that the camera simulator outputs three format image sequence correctly, which can be captured and displayed by frame gather. And the three-format image data can meet test requirements of the most equipment, shorten debugging time and improve the test efficiency.. ? 2015 SPIE.Accession Number: 20151100635506 -
Record 213 of
Title:Medical image registration based on salient texture
Author(s):Wang, Hong-Yu(1); Feng, Jun(1); Cui, Lei(1); He, Xiao-Wei(1); Qiu, Shi(2)Source: Guangxue Jingmi Gongcheng/Optics and Precision Engineering Volume: 23 Issue: 9 DOI: 10.3788/OPE.20152309.2656 Published: September 1, 2015Abstract:Traditional registration methods based on geometric measurement can not match the medical image with local deformation. To solve the problem, an improved Iterative Closest Points (ICP) algorithm about human visual cognitive process is proposed base on the salient texture. Firstly, the method establishes the model for the salient texture feature of a medical image based on Active Appearance Model (AAM) algorithm, and it gives the feature point with more salient for a larger weight to complete the image match in the first step. Then, it introduces the salient texture distance to the traditional space distance. By simulating the human visual cognitive process proposed by Gestalt, the linear decreasing weight is used to balance the two kinds of distance measuring methods. With the algorithm, a whole registration is obtained by the geometric distance in the early stage. On the other hand, the feature points of local deformation are accurately registrated with the texture features in the later stage. At last, a series of experiments are performed on real live images. The experiment results show that the algorithm can get a good matching result, and the registration accuracy is 78.82%, increasing by 22.22% as compared with those of other popular algorithms. The experimental results also show that it is not sensitive to the rotation of the images. It concludes that the algorithm solves the registration problems of local deformation in medical organs and achieves higher precision and stronger robustness. ?, 2015, Chinese Academy of Sciences. All right reserved.Accession Number: 20154401475341 -
Record 214 of
Title:Design and testing of infrared diffractive telescope imaging optical systems
Author(s):Zhang, Zhoufeng(1,2,3); Xie, Yongjun(1); Yin, Qinye(2); Kang, Fuzeng(1)Source: Optik Volume: 126 Issue: 24 DOI: 10.1016/j.ijleo.2015.09.079 Published: December 2015Abstract:Diffractive telescope is an updated imaging technology, it differs from conventional refractive and reflective imaging system, which is based on the principle of diffraction image. However, one of the great challenges of design this optical system is that the diffractive optical element focuses on different wavelengths of light at different points in space, thereby distorting the color characteristics of image. In this paper, we designs a long-wavelength infrared diffractive telescope imaging system with flat surface Fresnel lens and cancels the infrared optical system chromatic aberration by another flat surface Fresnel lens, achieving broadband light (from 8 μm to 12 μm) to a common focus. At last, the diffuse spot size and MTF function provide diffractive-limited performance. ? 2015 Elsevier GmbH. All rights reserved.Accession Number: 20154601551446 -
Record 215 of
Title:Stray light suppression of different ground-based photoelectric detection systems
Author(s):Yan, Peipei(1); Li, Gang(1); Liu, Kai(1); Jiang, Kai(1); Duan, Jing(1); Shan, Qiusha(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 44 Issue: 3 DOI: Published: March 25, 2015Abstract:The stray light characteristics of different catadioptric ground-based photoelectric detection system were analyzed. The relevant stray light suppression ways were discussed. Based on structure with middle image surface and the other one without middle image surface, two different suppression schemes for the stray light were provided respectively. Besides, the thermal radiation for the long wave infrared system was analyzed. The results show that adding out baffle to the catadioptric system without middle image surface can do well obviously in reducing stray light with large off-axis angles. However, adding stops and the inner baffle of primary mirror to the catadioptric system with middle image surface can reduce the outer stray light obviously. This can reduce the length and weight greatly. If the thermal radiation demand can be satisfied, the miniaturization and lightweight design had been realized. ?, 2015, Chinese Society of Astronautics. All right reserved.Accession Number: 20151800813119 -
Record 216 of
Title:Videometrics technology of flyers' pose
Author(s):Hu, Xiaoli(1,2,3); Su, Xiuqin(1); Zhang, Sanxi(3); Liu, Biao(3); Zhou, Zhiqiang(3)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9677 Issue: DOI: 10.1117/12.2199225 Published: 2015Abstract:In this paper pose measurement refers to flying pose measurement of rigid body including the pitch angle, yaw angel and roll angle. Pose measurement is of vital importance for such items as weapons settings, fault analysis and optimation design. Pose measurement based on optical images has many merits such as intuitive and non-contacted, which is a main method to measure pose currently. According to the parameters used and principle of the algorithms, the existing methods of pose measurement based on optical images are classified systematically and comprehensively for the first time as following: the methods of one station un-using camera's inner parameters are divided into the feature length ratio method and the direct linear transformation(DLT)method, otherwise they are divided into the perspective n points(PNP)problem and the optical and radar integration method, the axes from planes intersection using two stations extensible to multistation, and model matching applied to one or more stations, and then they are comparatively analyzed.At last combined with practical applications such as one or more stations, have or no model and inner parameters used or unused, some selection and improvement of key points are given practically. ? 2015 SPIE.Accession Number: 20155201714936