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浏览/检索结果: 共4条，第1-4条 帮助 限定条件 内容类型：会议论文    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 Emission characteristics of surface second-order metal grating distributed feedback semiconductor lasers 会议论文 lasers and their applications, 长春, 2011-07-31 作者:  Qin L(秦莉) 收藏  |  浏览/下载：12/0  |  提交时间：2012/05/12 Theoretical analysis of emission characteristics of second-order distributed feedback semiconductor lasers (EI CONFERENCE) 会议论文 Semiconductor Lasers and Applications IV, October 18, 2010 - October 19, 2010, Beijing, China Qin L.; Ye S.; Hu Y.; Zhang N.; Ning Y.; Liu Y.; Wang L. 收藏  |  浏览/下载：14/0  |  提交时间：2013/03/25 Based on the modified coupled-wave theory  the emission characteristics  including threshold gain  photon density distribution in the cavity  and external differential quantum efficiency for second-order DFB lasers are investigated. Numerical simulation results show that for given device structure with wavelength of 1.55 m  the feedback coupling coefficient and the surface radiation coupling coefficient of the second-order grating have great influence on the emission characteristics of the device. By choosing different duty cycles of the grating  we can change the two coupling coefficients  which affect the emission characteristics. For an overall consideration  an optimal duty cycle of 0.43 is chosen. The optimized results show that the device works without degeneracy modes and spatial burning hole. Besides  the side-mode suppress ratio (SMSR) and external differential quantum efficiency reach as high as 42 dB and 47%  respectively. 2010 SPIE.   Theoretical Analysis of Emission Characteristics of Second-order Distributed Feedback Semiconductor Lasers 会议论文 2010 Qin L.; Ye S. J.; Hu Y. S.; Zhang N.; Ning Y. Q.; Liu Y.; Wang L. J. 收藏  |  浏览/下载：11/0  |  提交时间：2013/03/28 Analysis of spectrum narrowing of diode laser bar (EI CONFERENCE) 会议论文 Semiconductor Lasers and Applications III, November 12, 2007 - November 13, 2007, Beijing, China Deng X.; Liu Y.; Yin H.; Feng G.; Gu Y.; Wang L. 收藏  |  浏览/下载：7/0  |  提交时间：2013/03/25 Laser diode bar (LDB) are used increasingly often for many applications  but spectral bandwidth of LDB are generally approximately 2-4nm  far too wide for many demanding applications  e.g. spin-exchange optical pumping  terahertz generation  and lidar. External-cavity feedback can improve the spectral properties of LD or LDB. However  spectrum narrowing of LDB is more difficult than that of LD. Bar curvature (i.e. "smile") produced in the manufacturing process affects the spectrum narrowing greatly. By geometrical optics approach and ORIGIN software  smile which can be corrected by plano-convex cylindrical lens is simulated and the result is in good agreement with experiment. The selection of grating which is also a critical factor of spectrum narrowing will be stated. Finally  an external cavity consisting of fast axis collimator  two plano-convex cylindrical lens and a diffraction grating is used. The scheme is implemented on a 19-element LDB and yields 3-fold reduction in spectral linewidth under the situation that all optical elements in the system which are not optimized. Further  we use a slit in the experiment and analyze the spectrum narrowing of each element in LDB.