大功率垂直腔面发射激光器的偏振控制

项目名称： 大功率垂直腔面发射激光器的偏振控制

项目编号： No.60876036

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 宁永强

作者单位： 中国科学院长春光学精密机械与物理研究所

项目金额： 35万元

中文摘要： 以垂直腔面发射激光器（VCSELs）结构为基础，通过外腔输出镜构成的扩展腔可以实现高效腔内激光倍频。但是垂直腔面发射激光器一般生长在（100）衬底上，其偏振方向的不稳定性给其应用带来了不良的影响，在进行腔内倍频实现蓝、绿光输出时，必须解决的关键问题是对VCSELs输出光束的偏振特性进行控制。针对高功率激光输出，本项目提出在P面制备非对称台面结构和电极结构的方案，使注入到有源区的电流密度分布具有一定的方向选择性，从而使有源区的光增益也具有一定的方向选择性。 首先，对大口径圆形和矩形垂直腔面发射激光器分别建立偏振理论模型，分析了VCSELs的偏振特性，同时也测试分析了大口径圆形器件的偏振特性，并且表征了温度的稳定性对偏振特性的影响。 其次，对垂直腔面发射激光器工艺制备的关键技术进行研究。引入矩形柱结构，在器件工艺上制备了980nm底发射和顶发射矩形垂直腔面发射激光器。最后，实验结果发现，水平偏振光和竖直偏振光在工作电流内共同存在，而且水平偏振光一直占据主导地位；水平偏振光的激射光谱相对于竖直偏振光发生蓝移现象。矩形VCSELs器件获得了一定高功率的偏振激光。

中文关键词： 垂直腔面发射激光器；大口径；偏振；矩形柱；高功率。

英文摘要： Based on the structure of Vertical-Cavity Surface-Emitting Lasers (VCSELs), high efficient inter-cavity frequency coupling for laser can be achieved by external-cavity shaping through output mirror in the outer cavity. But VCSELs is generally grown on the (100) substrate, whose instable polarization brings the bad effect in its applications. When emitting blue or green laser after inter-cavity frequency coupling, the key problem of controlling polarization for VCSELs must be solved. Aiming to the high-power output, it can be proposed that fabricating non-symmetrical mesa structure and electrode structure on P surface can be good to solve the problem of the project. Then the distribution of the current density injecting into the active region will be able to have the direction choosen, so the light gain of the active region will have the polarization election. Firstly, according to the structures of the circular and rectangular-shaped VCSELs, each polairzation theory models can be founded, and their polarization properties have been analyzed. At the same time, the polarization characteristics of the large-aperture circular-shaped devices have been measured and analyzed, and the dependence of the temperature stability on the polarization properties have been characterized. Secondly, the crucial technologies of processing fabrication for VCSELs have been investigated. 980-nm bottom-emitting and top-emitting VCSELs have been made in the device technics by introducing the rectangular post. Finally, from the testing results, it is found that horizontal and vertical polarization lights can coexist under the operating current, and the horizontal polarization can always dominate over the vertical one; blue-shift of horizontal polarization occurred with respect to the vertical polarization light. The rectangular-shaped devices can emit high-power laser with good polarization.

英文关键词： Vertical-Cavity Surface-Emitting Lasers; large-aperture; polarization; rectangular post; high-power.