Design and fabrication of high-coupling efficiency spot-size converter integrated laser diodes using three-dimensional BMP program

Attention is focused on butt-joint-type spot-size converter integrated laser diodes (SSC-LD's), which allow us to independently optimize the high-temperature performance and coupling efficiency. Increasing the coupling efficiency is achieved by using the three-dimensional (3-D) beam propagation method (BPM). Particular attention is paid to keeping coupling efficiency high, while minimizing variations due to fluctuations in fabrication conditions, such as composition and mesa width. The validity of this method is demonstrated by fabricating a device designed in this way; its coupling efficiency is in excellent agreement with the designed value.