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	A novel bottom-emitting vcsel's one-dimension array (EI CONFERENCE) 会议论文 OAI收割 Optoelectronic Materials and Devices III, October 27, 2008 - October 30, 2008, Hangzhou, China 作者: Wang L.; Wang L.; Wang L.; Liu Y.; Liu Y. 收藏 \| 浏览/下载：25/0 \| 提交时间：2013/03/25 A novel 980nm bottom-emitting VCSELs array with high power density and good beam property of Gaussian far-field distribution is reported. This array is composed of 5 symmetrically-arranged elements of 200m 150m and 100m-diameter with the center spacings of 300m and 250m respectively. The maximum power is 880mW at a current of 4A corresponding to lKW/cm2 average optical power density. The differential resistance is 0.09 with a threshold of 0.56A. The novel array is compared with a 300m-aperture-size single device and a 44 2-D array with 50m element aperture size and 250m centre spacing. The three devices have the same lasing area. The conclusion is that the novel array is better in the property of output power threshold current lasing spectra far-field distribution etc. 2008 SPIE.
	controllable ring search for anonymous routing protocols in manets 会议论文 OAI收割 Third International Conference on Wireless and Mobile Communications 2007, ICWMC 07, Guadeloupe, Guadaloupe, 37319 Zhang Yang; Fan Zhihua \| 收藏 \| 浏览/下载：9/0 \| 提交时间：2011/06/29 Algorithms Mobile telecommunication systems Problem solving Routing protocols Threshold elements Verification
	Application and comparison of resolving methods in SAR image ortho-rectification based on G.Konecny model - art. no. 67871P 会议论文 OAI收割 Mippr 2007: Multispectral Image Processing, Bellingham Yang, Bo; Wang, Chao; Zhang, Hong; Zhang, Bo 收藏 \| 浏览/下载：22/0 \| 提交时间：2014/12/07 SAR image ortho-rectification collinearity equation G.Konecny model exterior orientation elements solution method iteration threshold convergence precision
	Study of removing striping noise in CCD image (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China 作者: Liu H.; Liu H.; Liu H. 收藏 \| 浏览/下载：17/0 \| 提交时间：2013/03/25 Striping noise is the common system noise during formation of image using linear array CCD and has the character of periodicity directivity and banding distributing. It can be caused by errors in internal calibration devices or by slight gain/offset differences among the elements that conform the array of detectors. Striping noise covers up useful information in CCD image and brings adverse effect to image interpretation. On the basis of analyzing wavelet decomposed coefficient the regularities of distribution about striping noise in wavelet coefficient is found thereby the method of wavelet threshold selection which is suitable to striping noise distribution is put forward. According to Donoho's method about denoising using wavelet the image including striping noise is processed. Comparing the power spectrum of processed image with the one of original image polluted by striping noise in frequency field we find pulse brought by striping noise is removed and the goal which reserves image details and reduces stripes is achieved.
	High-power InGaAs/GaAs VCSEL's two-dimension arrays (EI CONFERENCE) 会议论文 OAI收割 ICO20: Lasers and Laser Technologies, August 21, 2005 - August 26, 2005, Changchun, China 作者: Liu Y.; Wang L.-J. 收藏 \| 浏览/下载：26/0 \| 提交时间：2013/03/25 Selectively oxidized InGaAs/GaAs vertical -cavity surface-emitting lasers (VCSEL) array at an emission wavelength of 980nm was reported. A 16 elements array with 200m aperture size (250m center spacing) of individual elements shows a CW output power of 1.21 W at room temperature resulting in 1 KW/cm2 average optical power density. The device threshold current is 1.32A The lasing peak wavelength is 981.9 nm the full width at half-maximum is 0.7 nm and the far-field divergence angle is about 17.The characteristics of a single device with a active region diameter of 800m is compared with that of a 2-D array with active region diameter of individual clement of 200m. These two kinds of devices have the same total lasing area. At the same current injection the single device has a higher threshold and a higher output power than the array. The red shift of single device is more obvious than that of the array's.
	High-power InGaAs VCSEL's single devices and 2-D arrays (EI CONFERENCE) 会议论文 OAI收割 Optoelectronic Materials and Devices for Optical Communications, November 7, 2005 - November 10, 2005, Shanghai, China 作者: Sun Y.; Wang L.; Wang L.; Wang L.; Liu Y. 收藏 \| 浏览/下载：23/0 \| 提交时间：2013/03/25 We report on bottom-emitting vertical-cavity surface-emitting lasers (VCSEL's) and laser arrays providing high output powers in the 980-nm wavelength regime. Single devices with active diameters of 500 m show high output powers of 1.95 W at room temperature. Its threshold current is 510 mA and the maximum spatially averaged optical power density is 0.93 kW/cm2. A 16 elements array with 200m aperture size (250m center spacing) of individual elements shows a CW output power of 1.21 W at room temperature resulting in a average optical power density of 1KW/cm2. The threshold current of the array is 1.32A and the lasing peak wavelength is 981.9 nm. The distinction of emission spectrums between the single device and the array is discussed.
	Theoretical analysis of 980nm high power Vertical External-cavity Surface-emitting Semiconductor Laser (VECSEL) (EI CONFERENCE) 会议论文 OAI收割 ICO20: Lasers and Laser Technologies, August 21, 2005 - August 26, 2005, Changchun, China 作者: Wang L.-J.; Wang L.-J.; Ning Y.-Q.; Qin L. 收藏 \| 浏览/下载：23/0 \| 提交时间：2013/03/25 By using bottom-emitting structure we will develop laser diode (LD) pumped 980 nm VECSEL with active region of InGaAs/GaAsP/AlGaAs system. Because the thickness of barrier layer and absorption layer exceed that of quantum well single well approximation model (KP method) can be used to calculate the band structure of VECSEL. The Schrodinger equation of finite deep potential well can be adopted to calculate the energy level structures of electron heavy and light holes. According to the transition selection rule we theoretically obtained the emitting wavelength of VECSEL and calculated quasi-Femi energy of valence band and conduction band based on the analysis of energy level structure of electron and holes. By analyzing the gain of strained quantum wells we calculated the gain of VECSEL using transition matrix elements of electron heavy and light holes. We give out the threshold gain output power and other characteristic parameters. We will study the configuration of VECSEL and pumping scheme. We designed external cavity mirror active region and bottom-emitting structure. A LD-pumped vertical external cavity surface-emitting laser whose output power is greater than 1.0 W can be predicted.
	Tandem electroabsorption modulators integrated with DFB laser by ultra-low-pressure selective-area-growth MOCVD for 10 GHz optical short pulse generation 期刊论文 OAI收割 semiconductor science and technology, 2005, 卷号: 20, 期号: 8, 页码: 882-885 Zhao, Q; Pan, JQ; Zhang, J; Zhou, GT; Wu, J; Wang, LF; Wang, W 收藏 \| 浏览/下载：123/47 \| 提交时间：2010/03/17 摘要: A novel device of tandem MQW EAMs monolithically integrated with a DFB laser is fabricated by an ultra-low-pressure (22 mbar) selective area growth MOCVD technique. Experimental results exhibit superior device characteristics with low threshold of 19 mA output light power of 4.5 mW and over 20 dB extinction ratio when coupled to a single mode fibre. Moreover over 10 GHz modulation bandwidth is developed with a driving voltage of 2 V. Using this sinusoidal voltage driven integrated device 10 GHz repetition rate pulse with an actual width of 13.7 ps without any compression elements is obtained.