Patent ID: 6804280
Filing Date: 2004-10-12
Classification: B82Y,H01S

Abstract:
A semiconductor edge-emitting laser comprising:a) an n-doped region, at least a part of which comprises a photonic band gap crystal including a layered structure comprising at least one layer, wherein each layer is doped by an n-typed impurity, wherein the layered structure has a periodically modulated refractive index, wherein the periodically modulated refractive index is modulated in a direction perpendicular to a direction of light propagation; b) a defect contiguous with said photonic band gap crystal, comprising: i) a light generating layer that emits light when exposed to an injection current when a forward bias is applied; c) a p-doped layered structure, comprising at least one layer, wherein each layer is doped by a p-type impurity, and wherein said p-doped layered structure is located on a side of said defect opposite said n-doped region, wherein the p-doped layered structure has a variable refractive index that hinders an extension of a fundamental mode to at least one doped layer within the p-doped layered structure and to a p-contact; wherein the fundamental mode of laser radiation is localized by the defect, while all other modes are extended over the photonic band gap crystal; wherein a total thickness of said photonic band gap crystal and said defect provides a low beam divergence.