Tunable fiber laser light source
AssigneeSantec Corporation
InventorChangho Chong
Life of this patent
Estimating the term…
Abstract
A loop is formed with an optical fiber by providing a gain medium having a gain with respect to an oscillation wavelength. Light retrieved by the optical circulator 13 from the optical fiber loop is enlarged and projected to a mirror 23. A diffraction grating 25 is provided with respect to the light reflected in the mirror. The diffraction grating 25 has a Littrow arrangemnt wherein the light is reflected in a same direction as incident light. A selected wavelength is changed in accordance with an incident angle with respect to the diffraction grating 25. Therefore, when the mirror 23 is rotated so as to change the selected wavelength, the oscillation wavelength can be changed at high speed.
Claims14
A tunable fiber laser light source, comprising:
- an optical fiber which serves as an optical path of a laser oscillation;
- a gain medium which is connected to said optical fiber and has a gain with respect to an oscillation wavelength;
- and
- a tunable optical filter which is connected to said optical fiber and continuously changes a bandpass wavelength,
- wherein
- said tunable optical filter includes:
- an optical beam deflector which periodically changes a reflection angle of an optical beam obtained from said optical fiber within a certain range;
- and
- a diffraction grating which inputs light deflected in said optical beam deflector and reflects light of a selected wavelength variable in accordance with an incident angle in a same direction as the incident angle;
- and
- a beam expander which enlarges a beam diameter of the optical beam deflected in said optical beam deflector, and
- said beam expander increases an enlargement rate as said selected wavelength is shortened so as to keep a bandwidth of an oscillated laser light constant.
A tunable fiber laser light source, comprising:
- an optical fiber which serves as an optical path of a laser oscillation;
- a gain medium which is connected to said optical fiber and has a gain with respect to an oscillation wavelength;
- and
- a tunable optical filter which is connected to said optical fiber and continuously changes a bandpass wavelength,
- wherein said tunable optical filter includes:
- an optical beam deflector which periodically changes a reflection angle of an optical beam obtained from said optical fiber within a certain range;
- and
- a diffraction grating which inputs light deflected in said optical beam deflector and reflects light of a selected wavelength variable in accordance with an incident angle in a same direction as the incident angle;
- and
- a beam expander which enlarges a beam diameter of the optical beam deflected in said optical beam deflector, and
- said beam expander increases an enlargement rate as said selected wavelength is shortened,
- wherein said tunable optical filter further includes a multiple reflection facet mirror which has a plurality of reflection facets (m≧2:
- m is a fixed integer) between said optical beam deflector and said diffraction grating, and
- said multiple reflection facet mirror is disposed in such a manner that an (i+1)th (i is a variable integer and one of 1 to m) facet thereof is tilted by φ/2m relative to an (i)th facet thereof when a range of deflection angles by said optical beam deflector is φ, the light from said optical beam deflector is inputted to (1 to m)th reflection facets per φ/m, and the reflected light is inputted to said diffraction grating.
Dependencies are inferred from the claim text.