Patent ID: 7463665
Filing Date: 2008-12-09
Classification: B82Y,H01S

Abstract:
1. A semiconductor laser diode comprising a light emitting portion on a substrate, wherein said light emitting portion includes: a first cladding layer; an active layer formed on said first cladding layer; a second cladding layer formed on said active layer and having a ridge stripe for injecting a current into said active layer; and a current blocking layer formed on both sides of said ridge stripe for confining said current in said ridge stripe, wherein a distance from a lower face of said current blocking layer to an upper face of said active layer is within a given range, and said current spreads beyond a width of said ridge stripe after passing said ridge stripe and before reaching said active layer, wherein said given range is set to have a lower limit corresponding to said distance obtained at a point where increase of lateral spread of said current becomes gentle against increase of said distance and an upper limit corresponding to said distance obtained at a point where increase of a full width at half maximum of an NFP (near field pattern) becomes gentle against the increase of said distance, wherein said given range is within the range of 0.65 μm to 1.2 μm, inclusive, wherein the full width at half maximum of the NFP is within the range of one time to three times the stripe width, wherein the width of said ridge stripe is within the range of 1 μm to 4 μm, inclusive, wherein said active layer is made of Al