Patent ID: 7696098

Claim:
A method of producing a unipolar semiconductor laser having desired performance characteristics including broad wavelength tuning comprising: a) forming an epitaxial structure by an epitaxial process on a semiconductor substrate wherein said epitaxial structure comprises: a1) a lower cladding layer on said semiconductor substrate; and, a2) a lower guiding layer on said lower cladding layer; and, a3) an active region on said lower guiding layer wherein said active region is suitable for lasing in a range of wavelengths around a given wavelength; and, a4) an upper guiding layer on said active region; and, a5) an upper cladding layer on said upper guiding layer; and wherein said semiconductor substrate and said epitaxial structure comprise doped semiconductor materials of only one conductivity type; and, b) forming a waveguide ridge by removing materials from said epitaxial structure; and, c) measuring the optical and electrical properties of said epitaxial structure on said semiconductor substrate and determining therefrom the nature of subsequent processing steps for producing a tunable unipolar laser having said desired performance characteristics; and, d) forming at least two cavity sections along said waveguide ridge with a coupling section between adjacent cavity sections, wherein the characteristics of said cavity sections and said coupling sections are formed so as to produce desired performance characteristics of said laser; and, e) forming upper electrodes on each of said at least two cavity sections; and f) forming a lower electrode on the bottom surface of said semiconductor substrate.