小发散角垂直腔面发射激光器的设计与制作

摘要

针对垂直腔面发射激光器单管及列阵器件较大的远场发散角,对大直径单管器件及列阵单元器件的有源区中的电流密度分布进行了模拟计算,分析了器件高阶横模产生的原因.分别采用优化p面电极直径和镀制额外金层结构来抑制单管及列阵器件远场光斑中的高阶边模,所制作的氧化孔径为600 μm的单管器件的远场发散角半角宽度从30°降低到15°;氧化孔径200μm,单元间距280μm的4×4列阵的远场发散角从30°降低到10°.%In this paper, dramatic improvements in vertical cavity surface emitting laser (VCSEL) performance have been obtained due to the advanced fabrication techniques and electrical confinement, as well as the structural design and growth of Bragg mirrors. A numerical simulation of current density distribution in the active of a large aperture single device and an array element were constructed. It is found that the current density at the perimeter of the oxide aperture is higher than at the center of the active region. The highe order transverse modes were excited due to the current crowding at the perimeter of the oxide aperture, which leading to large divergence angle. And it is suppressed by optimizing the p-contact diameter in a single device and suppressed by using an extra Au layer. The far-field angle of a single device with a 600 μm oxide aperture decreased from 30°to 15° when the p-contact diameter is optimized from 650 μm to 580 μm, and there is a slight increase in output power due to the optimization. By using an extra Au layer, the output aperture of a 4 ×4 two dimension array element is decreased to 180 μm, and the far-field angle of the array device is suppressed to 10°There is a slight drop in output power due to the introduction of the extra Au layer.