Semiconductor laser device

摘要

In a stripe geometry buried double heterostructure semiconductor laser device, a first semiconductor layer for effecting laser oscillation upon injection of carriers is sandwiched between second and third semiconductor layers having a wider band gap than the first semiconductor layer. This double heterostructure is partially rendered mesashaped to provide a stripe geometry, and the vacancy resulting from mesa formation is filled with a fourth semiconductor layer having a wider band gap than the first semiconductor layer. In this invention, the region of the first semiconductor layer which is spaced from both end facets of the device by a distance at least equal to the diffusion length of carriers has a narrower band gap that the other regions of the first semiconductor layer.