Patent ID: 7965753
Filing Date: 2011-06-21
Classification: H01S

Abstract:
1. A monolithic semiconductor laser comprising: a semiconductor substrate; a first wavelength semiconductor laser element provided on the semiconductor substrate, the first wavelength semiconductor laser element comprising a first wavelength light emitting layer forming portion which includes a first conductivity type cladding layer, an active layer and a second conductivity type cladding layer, for emitting a first wavelength light; and a second wavelength semiconductor laser element provided on a region of the semiconductor substrate, where the first wavelength semiconductor laser element is not formed, the second wavelength semiconductor laser element comprising a second wavelength light emitting layer forming portion which includes a first conductivity type cladding layer, an active layer and a second conductivity type cladding layer, for emitting a second wavelength light, wherein a buffer layer is provided between the substrate and the first conductivity type cladding layers of the first wavelength semiconductor laser element and the second wavelength semiconductor laser element, wherein materials forming the second conductivity type cladding layers for the first and second wavelength semiconductor laser elements are the same material, and wherein each of the second conductivity type layers of the light emitting layer forming portions of the first and second wavelength semiconductor laser elements is formed with a ridge structure in which a ridge portion is formed, and first conductivity type current constriction layers are provided at sides of the ridge portions, each of the first conductivity type current constriction layers of the first and second wavelength semiconductor laser elements having larger band gap energy than that of the active layer thereof, and being made of the same material each other.