Method for fabricating single-mode DBR laser with improved yield

Abstract

A method for fabricating a laser for generating single-longitudinal mode laser light at a lasing wavelength. A semiconductor active region for amplifying, by stimulated emission, light in the laser cavity at the lasing wavelength is formed. A grating is formed adjacent to the active region, the grating having a grating period corresponding to a Bragg wavelength substantially equal to the lasing wavelength. An intermediate section of the grating is removed to result in first and second pluralities of gratings separated by a gratingless intermediate section. First and second grating sections are formed comprising the first and second pluralities of gratings, where the first and second grating sections each have a first effective index of refraction. A gratingless phase-shift section is formed in said intermediate section, the phase-shift section being disposed adjacent to the active region and between the first and second grating sections and having a second index of refraction different than the first index of refraction. The phase-shift section has a length sufficient to impart a phase shift for light at the lasing wavelength sufficient to achieve single-longitudinal mode operation. Alternatively, a grating material layer is deposited adjacent to the active region, the grating material layer having a first section, a second section, and an intermediate section between the first and second sections. Gratings are formed in the first and second sections to form a first grating section in the first section, a second grating section in the second section, leaving a gratingless phase-shift section in the intermediate section.

Dependencies are inferred from the claim text.