External cavity-type of wavelength tunable semiconductor laser light source and method for tuning wavelength therefor

Claim 1

An external cavity-type wavelength tunable semiconductor laser light source comprising: a semiconductor laser having an anti-reflection film on one end facet thereof, a position of the laser defining a position of an optical axis; a diffraction grating positioned along the optical axis and disposed on an anti-reflection film side of the laser and for (i) receiving light beams emitted from the one end facet of the laser, and (ii) selecting a wavelength of a particular received light beam when a position of the diffraction grating with respect to the optical axis is changed; and a wavelength tunable member positioned in close cooperation with the diffraction grating and for (i) changing the position of the diffraction grating, (ii) the oscillating an output light beam emitted from an opposing end facet of the laser, oscillating based upon the wavelength of the particular light beam and the changed position, and (iii) tuning a wavelength of the oscillating output light beam, wherein the wavelength tunable member comprises: a supporting member for supporting the diffraction grating and having (i) an elastic body having a free end attached to a holding member, the holding member for attaching the diffraction grating thereto, the elastic body being deformed when the position of the diffraction grating is changed, and (ii) a fixed portion for fixing the elastic body to an optical base of the light source; a displacement member connected to the holding member and for moving the supported diffraction grating by deforming the elastic body; and a displacement control member for controlling an amount of displacement of the displacement means.

Claim 8

A method for tuning wavelength of an external cavity-type wavelength tunable semiconductor laser light source which comprises a semiconductor laser provided with an anti-reflection film on one end facet thereof, and a diffraction grating positioned along the optical axis and disposed on an anti-reflection film side of the laser, the method comprising: supporting the diffraction grating by an elastic mounting member; moving the diffraction grating to a desired position and a desired incident angle with respect to the laser, moving (i) by applying an elastic force from the elastic mounting member, and (ii) to select a wavelength of a light beam emitted from the laser; oscillating an output light beam based upon the wavelength of the emitted light beam, the desired position, and the desired incident angle; and tuning the wavelength of the oscillating light beam.

Claim 9

A method for tuning wavelength of an external cavity-type wavelength tunable semiconductor laser light source which comprises a semiconductor laser provided with an anti-reflection film on one end facet thereof, and a diffraction grating positioned along the optical axis and disposed on an anti-reflection film side of the laser, the method comprising: supporting the diffraction grating by an elastic mounting member; moving the diffraction grating to a desired position and a desired incident angle with respect to the laser, moving (i) by applying an elastic force from the elastic mounting member, and (ii) to select a wavelength of a light beam emitted from the laser; oscillating an output light beam based upon the wavelength of the emitted light beam, the desired position, and the desired incident angle; and tuning the wavelength of the oscillating light beam.