Integrated semiconductor laser producing light of different wavelengths

Abstract

A method of making an integrated semiconductor laser on a common substrate including at least two active regions, each active region oscillating at a respective, different wavelength, including producing a precursor laser structure by successively growing on a semiconductor substrate a first conductivity type semiconductor first cladding layer, an active layer including at least one compound semiconductor quantum well layer sandwiched between compound semiconductor quantum barrier layers, and a second conductivity type semiconductor second cladding layer, the quantum barrier layers having a larger energy band gap than and including at least one more element than the quantum well layer, annealing the precursor structure including controlling at first and second spaced apart regions the diffusion of the at least one more element from the quantum barrier layers into the quantum well layer to produce first and second spaced apart active regions in the active layer having different effective lasing energy band gaps, and forming respective electrical contacts to the first and second cladding layers on opposite sides of each of the first and second active regions.