Abstract:
PROBLEM TO BE SOLVED: To provide an optical semiconductor device capable of efficiently heating an optical waveguide using heat generated in a heater, and to provide a laser chip and a laser module. SOLUTION: The optical semiconductor device (100) includes a semiconductor substrate (101), an optical semiconductor region (102) provided on the semiconductor substrate and having a width smaller than the width of the semiconductor substrate, and a heater (103) provided on the optical semiconductor region. The optical semiconductor region includes a clad region (104), an optical waveguide layer (105) provided in the clad region and having a refractive index larger than the refractive index of the clad region, and a low thermal conductivity layer (106) provided between the optical waveguide layer and the semiconductor substrate and having a thermal conductivity smaller than the thermal conductivity of the clad layer. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a tunable semiconductor laser capable of stabilizing a mode of a laser oscillation with a newly structured SG-DR waveguide. SOLUTION: The semiconductor laser (200) comprises a first region having a diffraction grating (2), and a first diffraction grating region (3) having a plurality of segments having a second region connected to the first region and becoming a space part. At least two optical lengths out of the plurality of second regions are different each other and refraction factors of each segment are respectively variable. The difference of at least two optical lengths out of the plurality of second regions makes a peak reflection intensity of a longitudinal mode in the first diffraction grating region have a wavelength dependence. This can provide a stable laser oscillation in the wavelength range with the peak reflection insensity of the longitudinal mode in the first diffraction grating region relatively large. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a light source of wide wavelength variable width in which light output fluctuation at wavelength adjustment is suppressed, in a distribution reflecting type tunable laser, related to an optical transmission device. SOLUTION: Related to a waveguide type optical element in which an active waveguide and a distributed Bragg reflector are optically coupled with each other in a specified region on a semiconductor substrate, a distribution reflecting type laser with wavelength control function is provided, in which a quantum well layer, having the number of period of one or more layer, and having a structure separated from the active waveguide, is formed on a part of or all over the distributed Bragg reflector. COPYRIGHT: (C)2004,JPO&NCIPI