梯形截面掩埋结构垂直腔面发射半导体激光器的横模控制

Transverse Mode Control of Barried Structure Vertical Cavity Surface Emitting Lasers With Trapezoid Section

本文采用求解光场方程，载流子扩散方程和模式耦合方程自洽解的方法研究了具有梯形截面掩埋结构垂直腔面发射半导体激光器的横模控制．计算了掩埋限制区的倾角以及激光器有源区半径等对基模和一阶模的辐射损耗的影响．结果表明，在这种结构的半导体激光器中，一阶模的辐射损耗总比基模大，因而可以很好地抑制高阶横模．增大限制区的倾角，虽然有利于实现单基模工作，但是因为基模的辐射损耗也随之增大，从而激光器的阈值电流也相应增大．对于一定的有源区半径，我们找到了不同限制区倾角时单基横模工作的注入电流区域．从而可以确定在特定的注入电流范围内实现单基横模的最佳限制区倾角．

Abstract Using a method for finding self consistent solutions of the optical field, carrier diffusion, and mode coupling equations, we have studied the transverse mode control of burried structure vertical cavity surface emitting lasers with trapezoid section. The influence of the slope angle of the confining region, the radius of the active region, and injected current on the radiation losses of the fundamental mode and the first order mode have been investigated. The results show that the radiation loss of the first order mode is always larger than that of the fundamental mode, so that the high order transverse mode can be suppressed very well in this laser. Increasing the slope angle of the confining region is in favour of single fundamental mode operation. However, the radiation loss of the fundamental mode also increases with the slope angle, giving rise to a large threshold current. For a given radius of the active region, we have calculated an injected current range of single mode operation for different slope angles. Thus, the best slope angle of the confining region for single mode operation can be obtained in a given injected current range.