基于微光学技术设计得到了偏振稳定垂直腔面发射激光器结构，将亚波长光栅结构集成在上分布布拉格反射镜表面，光栅周期小于材料中光波长，透射波和反射波中仅包含零级衍射，避免了高级次衍射造成的损耗．集成光栅后不同偏振方向光阈值增益不同，从而实现偏振控制．实验结果显示，集成亚波长光栅结构后，整个激射过程中偏振方向被固定在平行于光栅槽方向上，获得偏振稳定激光输出，正交偏振抑制比大于12dB，且阈值电流仅增大7．14％．%By introducing sub-wavelength grating into an oxide-confined 980-nm vertical-cavity surface-emitting laser (VCSEL), the VC- SEL with a stable polarization is realized. A sub-wavelength zero-order grating period is smaller than the wavelength in the semicon- ductor medium. This choice avoids a reduction in efficiency due to higher diffracting light. After the grating is etched, the threshold gains of E-fields parallel and perpendicular to the grating groves direction are different. The polarization therefore would be controlled. Good laser characteristics are obtained: the orthogonal polarization suppression ratio is over 12 dB and the threshold current increases just 7.14%.
展开▼
