亚波长光栅调制的偏振稳定垂直腔面发射激光器研究

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12 dB, 且阈值电流仅增大7.14%.

Polarization stable vertical-cavity surface-emitting laser with surface sub-wavelength gratings

By introducing sub-wavelength grating into an oxide-confined 980-nm vertical-cavity surface-emitting laser (VCSEL), the VCSEL with a stable polarization is realized. A sub-wavelength zero-order grating period is smaller than the wavelength in the semiconductor 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%.