Patent ID: 7835008

Claim:
A semiconductor laser gyro comprising a photodetector and a semiconductor laser that emits first and second laser lights, wherein: the photodetector is disposed in a position where an interference fringe is formed by the first and second laser lights, the semiconductor laser includes an active layer as well as first and second electrodes for injecting a carrier into the active layer, the first laser light is one obtained through emission of a part of laser light (L 1 ) that circulates on a polygonal path in the active layer, the second laser light is one obtained through emission of a part of laser light (L 2 ) that circulates on the polygonal path in an opposite direction to the laser light (L 1 ), the active layer has a planar shape that is not ring-shaped, the polygonal path is a rhombic path, the active layer has first to fourth end faces that are formed in positions corresponding to first to fourth corners of the rhombic path, internal angles of the first and second corners that oppose each other on the rhombic path are smaller than internal angles of the third and fourth corners, both the first and second laser lights are emitted from the first end face that is formed in a position corresponding to the first corner, and a region where the first electrode and a semiconductor layer of the semiconductor laser are in contact with each other is formed into an approximately rhombic shape corresponding to the rhombic path.