Patent ID: 8588266
Filing Date: 2013-11-19
Classification: H01S

Abstract:
1. A semiconductor laser comprising: a first diffractive grating area that has a plurality of segments; a second diffractive grating area that has another plurality of segments; and a plurality of heaters controlling a refractive index of the segments of the first diffractive grating area, wherein the plurality of segments of said first diffractive grating area includes one segment and other segments, the one segment being positioned at an edge of the first diffractive grating area that is closest to the second diffractive grating area, wherein each of the plurality of segments of said first diffractive grating area has a first area including a diffractive grating and a second area that is a space area adjacent the first area, optical lengths of at least two of the second areas of the other segments being different from each other, and a refractive index of the other segments being changeable by the plurality of heaters, the plurality of heaters being provided above the segments, wherein each of the another plurality of segments of said second diffractive grating area has another first area including another diffractive grating and another second area that is another space area adjacent the another first area, and optical lengths of all of the another second areas being substantially equal to each other, and wherein a length of the first area is shorter than a length of the second area.