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浏览/检索结果: 共7条，第1-7条 帮助 限定条件 专题：长春光学精密机械与物理研究所    第一署名单位    第一作者单位    通讯作者单位     已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 Improved method of target detection on optoelectronic hybrid joint transform correlator in cluttered scences (EI CONFERENCE) 会议论文 2011 3rd International Conference on Mechanical and Electronics Engineering, ICMEE 2011, September 23, 2011 - September 25, 2011, Hefei, China Qian Y.; Yang L.; Cheng X.; Hong X. 收藏  |  浏览/下载：14/0  |  提交时间：2013/03/25 A classical joint transform correlator (JTC) usually yields large correlation sidelobes as well as a large correlation peak width  strong zero-order peak  and low diffraction efficiency  which make the detection ability of JTC lower. To overcome these difficulties  firstly  a joint power spectrum (JPS) subtraction technique in Fourier plane was proposed  where reference image power spectrum and object image power spectrum are subtracted from the JPS before inverse Fourier-transform operation  it is obvious that the modified JPS removes the zero-order term. Secondly  a fringe-adjusted filter (FAF) was presented to suppress sidelobes and noises. The modified JPS is multiplied by a FAF before the inverse Fourier-transform operation to obtain the cross-correlation peak. Computer simulations demonstrated the improved method can obviously remove zero-order diffraction and effectively suppress the sidelobes and noises compared with classic JTC  and then improve the detection ability for JTC. Experimental results presented the sharp correlation peak and also confirmed the method effectiveness. (2012) Trans Tech Publications  Switzerland.   Image mosaic technique based on the information of edge (EI CONFERENCE) 会议论文 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012, July 31, 2012 - August 2, 2012, Guilin, Guangxi, China Wu Z.-G.; Wang M.-J.; Wang Y.-Q. 收藏  |  浏览/下载：27/0  |  提交时间：2013/03/25 Image mosaic is an important branch in the field of image processing. This paper designs and realizes an image mosaic technique based on the information of edge. The technology is suitable for engineering application. First of all  two images of the adjoining frames are processed by convolution operation  get the edge images. And then we cut edge image into pieces and compute their spatial frequency. According to the value of the spatial frequency select reasonable registration model group. We compute correlation strength and the value of movement offset which are the model group and the current frame edge image. We can complete image mosaic by them. We use video sequence which of the resolution is 1024 * 768 do the experiment. The results show that the method has good effect and strong adaptability. Algorithm is high efficiency which running time is 24 ms. It is suitable for real-time processing requirements of the application. This method is an effective mosaic technique which is suitable for engineering application. 2012 IEEE.   Image parallel processing based on GPU (EI CONFERENCE) 会议论文 2010 IEEE International Conference on Advanced Computer Control, ICACC 2010, March 27, 2010 - March 29, 2010, 445 Hoes Lane - P.O.Box 1331, Piscataway, NJ 08855-1331, United States Zhang N.; Wang J.-L.; Chen Y.-S. 收藏  |  浏览/下载：21/0  |  提交时间：2013/03/25 In order to solve the compute-intensive character of image processing  based on advantages of GPU parallel operation  parallel acceleration processing technique is proposed for image. First  efficient architecture of GPU is introduced that improves computational efficiency  comparing with CPU. Then  Sobel edge detector and homomorphic filtering  two representative image processing algorithms  are embedded into GPU to validate the technique. Finally  tested image data of different resolutions are used on CPU and GPU hardware platform to compare computational efficiency of GPU and CPU. Experimental results indicate that if data transfer time  between host memory and device memory  is taken into account  speed of the two algorithms implemented on GPU can be improved approximately 25 times and 49 times as fast as CPU  respectively  and GPU is practical for image processing. 2010 IEEE.   808nm high-power high-efficiency GaAsP/GaInP laser bars (EI CONFERENCE) 会议论文 Optoelectronic Materials and Devices III, October 27, 2008 - October 30, 2008, Hangzhou, China Wang Y.; Yang Y.; Qin L.; Wang C.; Yao D.; Liu Y.; Wang L. 收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25 808nm high power diode lasers  which is rapidly maturing technology technically and commercially since the introduction in 1999 of complete kilowatt-scale diode laser systems  have important applications in the fields of industry and pumping solid-state lasers (DPSSL). High power and high power conversion efficiency are extremely important in diode lasers  and they could lead to new applications where space  weight and electrical power are critical. High efficiency devices generate less waste heat  which means less strain on the cooling system and more tolerance to thermal conductivity variation  a lower junction temperature and longer lifetimes. Diode lasers with Al-free materials have superior power conversion efficiency compared with conventional AlGaAs/GaAs devices because of their lower differential series resistance and higher thermal conductivity. 808nm GaAsP/GalnP broad-waveguide emitting diode laser bars with 1mm cavity length have been fabricated. The peak power can reach to 100.9W at 106.5A at quasicontinuous wave operation (200s  1000Hz). The maximum power conversion efficiency is 57.38%. Based on these high power laser bars  we fabricate a 1 3 arrays  the maximum power is 64.3 W in continuous wave mode when the current is 25.0A. And the threshold current is 5.9A  the slope efficiency is 3.37 W/A. 2008 SPIE.   The spectral feature analysis of semiconductor thin disk laser (EI CONFERENCE) 会议论文 Optoelectronic Materials and Devices II, November 2, 2007 - November 5, 2007, Wuhan, China He C.-F.; Qin L.; Li J.; Cheng L.-W.; Liang X.-M.; Ning Y.-Q.; Wang L.-J. 收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25 The semiconductor thin disk laser is a new type of semiconductor laser. This work gives the basic operation function of semiconductor disk laser  and analyses the heat effect by the experimentally measured photoluminescence spectrum of the laser chip at different pump power and different temperature. We can see that: with increasing pump power  the thermal effects of the gain material becomes seriously and causes the saturation of carrier lifetime  so the electron-hole pair created in the absorbtion layer have no enough time to rate to one of the wells  and the non-radiative recombination happens in the barrier. When the thermal effects becomes stronger  the chip will not lasing. This phenomenon is from the smaller energy offset between barrier and quantum well. We optimize the original structure design and experimental technology. A non-absorbing AlGaAs layer who is transparent to the pumping and laser wavelength is added to confine the carriers in the quantum wells. At the same time a DBR with double reflecting band is induced to improve the absorbing efficiency of the pumping light. The single QW is replaced by the three narrow QWs  This three QWs structure can add the quantum state of QW  increase the recombination probability of carriers in the QWs and reduce the heat effect. The chemical etch equipment is also improved to control the surface unevenness to be within 50 nm.   High power VCSEL device with periodic gain active region (EI CONFERENCE) 会议论文 Optoelectronic Materials and Devices II, November 2, 2007 - November 5, 2007, Wuhan, China Ning Y. Q.; Qin L.; Sun Y. F.; Li T.; Cui J. J.; Peng B.; Liu G. Y.; Zhang Y.; Liu Y.; Wang L. J.; Cui D. F.; Xu Z. Y. 收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25 High power vertical cavity surface emitting lasers with large aperture have been fabricated through improving passivation  lateral oxidation and heat dissipation techniques. Different from conventional three quantum well structure  a periodic gain active region with nine quantum wells was incorporated into the VCSEL structure  with which high efficiency and high power operation were expected. The nine quantum wells were divided into three groups with each of them located at the antinodes of the cavity to enhance the coupling between the optical field and the gain region. Large aperture and bottom-emitting configuration was used to improve the beam quality and the heat dissipation. A maximum output power of 1.4W was demonstrated at CW operation for a 400m-diameter device. The lasing wavelength shifted to 995.5nm with a FWHM of 2nm at a current of 4.8A due to the internal heating and the absence of active water cooling. A ring-shape farfield pattern was induced by the non-homogeneous lateral current distribution in large diameter device. The light intensity at the center of the ring increased with increasing current. A symmetric round light spot at the center and single transverse mode operation with a divergence angle of 16 were observed with current beyond 4.8A.   Design and DSP implementation of star image acquisition and Star point fast acquiring tracking (EI CONFERENCE) 会议论文 2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, November 2, 2005 - November 5, 2005, Zian, China Zhou G.; Wang X.; Hao Z. 收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25 Star sensor is a special high accuracy photoelectric sensor. Attitude acquisition time is an important function index of star sensor. In this paper  the design target is to acquire 10 samples per second dynamic performance. On the basis of analyzing CCD signals timing and star image processing  a new design and a special parallel architecture for improving star image processing are presented in this paper. In the design  the operation moving the data in expanded windows including the star to the on-chip memory of DSP is arranged in the invalid period of CCD frame signal. During the CCD saving the star image to memory  DSP processes the data in the on-chip memory. This parallelism greatly improves the efficiency of processing. The scheme proposed here results in enormous savings of memory normally required. In the scheme  DSP HOLD mode and CPLD technology are used to make a shared memory between CCD and DSP. The efficiency of processing is discussed in numerical tests. Only in 3.5ms is acquired the five lightest stars in the star acquisition stage. In 43us  the data in five expanded windows including stars are moved into the internal memory of DSP  and in 1.6ms  five star coordinates are achieved in the star tracking stage.