Patent ID: 7756178
Filing Date: 2010-07-13
Classification: B82Y,H01S

Abstract:
1. A quantum cascade laser comprising: an active layer, having a cascade structure, in which quantum well light emitting layers and injection layers are laminated alternately on a semiconductor substrate formed of InP, and generating light by intersubband transitions in a quantum well structure; a waveguide core layer, formed adjacent said active layer; and a waveguide clad layer, formed adjacent said waveguide core layer at the side opposite the side of said active layer; and wherein said waveguide core layer is formed of a group III-V compound semiconductor, containing, as the group V elements, N and at least one element selected from the group consisting of As, P, and Sb, and formed so as to be lattice matched with said semiconductor substrate; wherein said waveguide clad layer contains a high-concentration doped layer formed of a group III-V compound semiconductor, containing, as the group V elements, N and at least one element selected from the group consisting of As, P, and Sb.