Patent ID: 6782022
Filing Date: 2004-08-24
Classification: H01S

Abstract:
A distributed feedback (DFB) semiconductor laser device comprising:first and second cladding layers forming at least a portion of a resonant cavity having a cavity length; an active layer region provided between said first and second cladding layers and within said resonant cavity, the active layer region being configured to radiate light in an optical gain distribution having a peak wavelength; an embedding layer also provided between said first and second cladding layers and within said resonant cavity, the embedding layer having a refractive index; and a diffraction grating embedded within said embedding layer and having a bandgap wavelength and a refractive index, said diffraction grating configured to select an emission wavelength of said resonant cavity independently of the peak wavelength in the optical gain distribution of said active layer region, wherein said embedding layer and diffraction grating are configured to provide operational characteristics satisfying the relationship 0a difference in the refractive index of said diffraction grating and said embedding layer satisfies the relationship 0.291âˆ’n2, where n1 is the refractive index of the diffraction grating and n2 is the refractive index of the embedding layer.