Semiconductor laser having an etched mirror and a narrow stripe width, with an integrated photodetector

摘要

In an integrated optical semiconductor device wherein a stripe geometry laser diode is separated from a photodetector by an etched groove, the stripe region has a smaller width, such as 2 to 3 microns, than a carrier generating region of the photodetector. The stripe region is preferably rendered thicker than the carrier generating region, in which case the carrier generating region is more preferably made of a seimconductor material having a narrower band gap than the material of the stripe region. The stripe region may be defined by a buried mesa structure. Alternatively, the stripe region may be bounded transversely of a pair of heterojunctions therefor by a pair of channel-shaped regions of a semiconductor material having a wider bank gap than the material of the stripe region. In this event, the carrier generating region is divided into three parts by extensions of the channel-shaped regions. Most preferably, the carrier generating region has a light receiving end which is not parallel to a light emitting end of the stripe region. The light receiving end may be cylindrical.