Patent ID: 6638773
Filing Date: 2003-10-28
Classification: H01S

Abstract:
A method for fabricating a laser for generating single-longitudinal mode laser light at a lasing wavelength, the method comprising the steps of:(a) forming a semiconductor active region for amplifying, by stimulated emission, light in the laser cavity at the lasing wavelength; (b) forming a grating adjacent to the active region, the grating having a grating period corresponding to a Bragg wavelength substantially equal to the lasing wavelength; (c) removing an intermediate section of the grating to result in first and second pluralities of gratings separated by a gratingless intermediate section; (d) forming a first grating section comprising the first plurality of gratings and having a first reflectance and a first effective index of refraction; (e) forming a second grating section comprising the second plurality of gratings and having a second reflectance and the first effective index of refraction, wherein said second reflectance is greater than said first reflectance; and (f) forming a gratingless phase-shift section 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 effective index of refraction, wherein 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 and each of the lengths of the first grating section, the second grating section, and the phase-shift section is no more than about three times the length of the other two of said sections.