Patent ID: 6337868
Filing Date: 2002-01-08
Classification: H01S

Abstract:
A distributed feedback semiconductor laser comprising:a cavity extending in a cavity-axial direction, said cavity including a plurality of regions; a waveguide with a diffraction grating and an active layer extending along the cavity-axial direction, said waveguide being formed in said regions, said diffraction grating having first and second regions including a plurality of periodical striped grooves, respectively, said grooves being buried in said first region with a member having a first refractive index, said grooves being buried in said second region with a member having a second refractive index, and different first and second polarization modes being defined by said first and said second regions of said diffraction grating; light intensity distribution control means comprising a phase shift section for shifting a phase of a periodical change in a refractive index for one of the first and second polarization modes due to said diffraction grating while not shifting a phase of a periodical change in a refractive index for the other of the first and second polarization modes due to said diffraction grating; and control means for independently stimulating at least two of said regions of said cavity.