Semiconductor laser device capable of controlling wavelength shift
AssigneeHitachi, Ltd.
InventorsAkihiko Oka, Shinji Sakano, Naoki Chinone, Tsukuru Ohtoshi, Kazuhisa Uomi, Tomonobu Tsuchiya, Makoto Okai
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Abstract
A wavelength-tunable semiconductor laser device presenting a large wavelength-tunable range or a very-high-speed modulating semiconductor laser device having a distributed feedback structure including a diffraction grating as in the case of a DBR laser or a DFB laser incorporates therein a plurality of active layers differing from one another in constituent elements or composition ratio or thickness for reducing spectral line widths, while improving single-mode spectral oscillation characteristics.
Claims21
A semiconductor laser device comprising:
- a plurality of active regions exhibiting different gain peak wavelengths, for generating light having a specific wavelength different from the gain peak wavelengths;
- resonator means for amplifying and oscillating the light by selectively amplifying the light of the specific wavelength;
- and
- means for pumping the active regions.
A semiconductor laser device comprising:
- a first and a second active region for emitting light, the first active region having a first gain peak wavelength and the second active region having a second gain peak wavelength:
- means for injecting carriers into the active regions for emitting light:
- and
- a diffraction grating for selecting light of a specific wavelength of those emitted by the active regions, being disposed in the vicinity of the active regions
- wherein the first gain peak wavelength of the first active region is smaller than the specific wavelength.
A semiconductor laser device comprising:
- a plurality of active regions;
- means for injecting carriers into the active regions for emitting light;
- and
- a diffraction grating provided in the vicinity of the active regions and on an optical axis along which light of a specific wavelength of those emitted by said active regions travels in a body of the device;
- wherein said plurality of the active regions are mutually different with respect to gain peak wavelength.
A semiconductor laser device comprising:
- a DBR region formed with a diffraction grating for amplifying light of an oscillation wavelength and including a first active optical waveguide;
- and
- an optical amplification region including a second active optical waveguide and means for pumping the second active optical waveguide so as to emit light.
- wherein the first and the second active optical waveguides are optically coupled and a gain peak wavelength of the first active optical waveguide is smaller than the oscillation wavelength.
A semiconductor laser device comprising
- a plurality of active waveguides exhibiting different gain peak wavelengths;
- means for exciting the active waveguides so as to emit light;
- means for amplifying the light emitted by the active waveguides;
- and
- a passive waveguide for optically coupling the active waveguides therethrough.
Dependencies are inferred from the claim text.