Semiconductor laser device and method for suppressing injection current

A method for providing light from a semiconductor device comprising:

• radiating light from an active region of said device in the presence of an injection current;
• providing a diffraction grating within a resonator of said device and positioned along a portion of the length of said active region;
• and
• suppressing said injection current in said first portion of the length of the active region.

A semiconductor device comprising:

• means for radiating light from an active region of said device in the presence of an injection current;
• means for selecting a portion of said radiated light to be emitted by said semiconductor laser device as an output light beam;
• and
• means for suppressing said injection current in said first portion of the length of the active region.

A semiconductor laser module comprising:

• a semiconductor laser device comprising:
• an active region configured to radiate light in the presence of an injection current,
• a light reflecting facet positioned on a first side of said active region,
• a light emitting facet positioned on a second side of said active region thereby forming a resonator between said light reflecting facet and said light emitting facet,
• a diffraction grating positioned within said resonator along a portion of the length of said active region, and
• a non-current injection area formed along said diffraction grating so as to suppress injection current in said first portion of the length of the active region;
• and
• a wave guide device for guiding said laser beam away from the semiconductor laser device.

An optical fiber amplifier comprising:

• a semiconductor laser device comprising:
• an active region configured to radiate light in the presence of an injection current,
• a light reflecting facet positioned on a first side of said active region,
• a light emitting facet positioned on a second side of said active region thereby forming a resonator between said light reflecting facet and said light emitting facet,
• a diffraction grating positioned within said resonator along a portion of the length of said active region, and
• a non-current injection area formed along said diffraction grating so as to suppress injection current in said first portion of the length of the active region;
• and
• an amplifying fiber coupled to said semiconductor laser device and configured to amplify a signal by using said light beam as an excitation light.

A wavelength division multiplexing system comprising:

• a transmission device configured to provide a plurality of optical signals having different wavelengths;
• an optical fiber amplifier coupled to said transmission device and including a semiconductor laser device comprising:
• an active region configured to radiate light in the presence of an injection current,
• a light reflecting facet positioned on a first side of said active region,
• a light emitting facet positioned on a second side of said active region thereby forming a resonator between said light reflecting facet and said light emitting facet, a diffraction grating positioned within said resonator along a portion of the length of said active region, and
• a non-current injection area formed along said diffraction grating so as to suppress injection current in said first portion of the length of the active region;
• and
• a receiving device coupled to said optical fiber amplifier and configured to receive said plurality of optical signals having different wavelengths.

A Raman amplifier comprising:

• a semiconductor laser device comprising:
• an active region configured to radiate light in the presence of an injection current,
• a light reflecting facet positioned on a first side of said active region,
• a light emitting facet positioned on a second side of said active region thereby forming a resonator between said light reflecting facet and said light emitting facet, a diffraction grating positioned within said resonator along a portion of the length of said active region, and
• a non-current injection area formed along said diffraction grating so as to suppress injection current in said first portion of the length of the active region;
• and
• a fiber coupled to said semiconductor laser device and configured to carry a signal that is amplified based on said light beam being applied to said fiber.

A semiconductor device comprising:

• an active layer configured to radiate light in the presence of an injection current;
• a light reflecting facet positioned on a first side of said active layer;
• a light emitting facet positioned on a second side of said active layer thereby forming a resonator between said light reflecting facet and said light emitting facet;
• a diffraction grating positioned within said resonator along a portion of the length of said active layer, wherein said semiconductor device is configured to emit a light beam having multiple longitudinal modes within the gain profile of the semiconductor device;
• and
• a non-current injection area formed along said diffraction grating so as to suppress injection current in said portion of the length of the active layer.