Patent ID: 6608855
Filing Date: 2003-08-19
Classification: H01S

Abstract:
An edge-emitting laser for generating single-longitudinal mode laser light at a lasing wavelength, the laser comprising:a semiconductor active region for amplifying, by stimulated emission, light in the laser cavity at the lasing wavelength; a first grating section adjacent to the active region and having a first reflectance and a first effective index of refraction; a second grating section adjacent to the active region and having a second reflectance and the first effective index of refraction, the first and second grating sections having a Bragg wavelength substantially equal to the lasing wavelength; and a gratingless phase-shift section disposed adjacent to the active region and between the first and second grating sections and having a second index of refraction greater 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.