Patent ID: 9300115
Filing Date: 2016-03-29
CPC Classification: H01S

Claim Text:
1. A quantum cascade laser comprising: a semiconductor region having a main surface including a first region and a second region arranged in a first axis direction; a stacked semiconductor layer disposed on the second region of the semiconductor region, the stacked semiconductor layer including a core layer and an upper cladding layer disposed on the core layer; and a distributed Bragg reflector disposed on the first region of the semiconductor region, the distributed Bragg reflector including at least one semiconductor wall having a side surface extending in a second axis direction perpendicular to the main surface of the semiconductor region, the semiconductor wall including the core layer and the upper cladding layer, wherein the side surface of the semiconductor wall is optically coupled to an end facet of the stacked semiconductor layer, and the side surface of the semiconductor wall includes a side surface of the core layer having a recess portion depressed from a side surface of the upper cladding layer in the semiconductor wall.