Internal-reflection-interference semiconductor laser device

Claim 2

In an internal-reflection-interference semiconductor laser device having one radiation emitting facet, another facet opposed to said radiation emitting facet, and an internal reflecting section, and comprising: a semiconductor substrate; a first electrode formed under said substrate; a first cladding layer formed on said substrate; an active layer formed on said first cladding layer; a second cladding layer formed on said active layer; a cap layer formed on said second cladding layer; a first laser operation area ranging from said radiation emitting facet to the internal reflecting section; and a second laser operation area ranging from the other facet to the internal reflecting section, wherein: the internal-cavity length l 1 of said first laser operation area is shorter than the internal-cavity length l 2 of said second laser operation area, and the reflectivity R 1 at the radiation emitting facet is smaller than the reflectivity R 2 at the other facet.

Claim 3

An internal-reflection-interference semiconductor laser device according to claim 1, wherein said internal reflecting section is located along a V-shaped channel which is formed on the substrate in a manner to be perpendicular to the laser oscillation direction.

Claim 4

An internal-reflection-interference semiconductor laser device comprising: a body of semiconductor material capable of radiation emission and having opposed first and second facet surfaces from which the radiation is capable of being emitted, said body comprising: a semiconductor substrate having a channel extending along one surface generally parallel with said facet surfaces, said channel being positioned closer to said first facet surface than to said second facet surface; a first cladding layer formed on said one substrate surface having said channel; an active layer formed on said first cladding layer; a second cladding layer formed on said active layer; and a cap layer formed on said second cladding layer; said channel defining an internal reflecting section in said body with a first laser operation area ranging from said first facet surface to said internal reflecting section and a second laser operation area ranging from said second facet surface to said internal reflecting section, said first laser operation area having a length l 1 less than the length l 2 of said second laser operation area; first and second reflectors disposed on said first and second facet surfaces, respectively, said first reflector producing a reflectivity R 1 less than the reflectivity R 2 produced by said second reflector.

Claim 5

An internal-reflection-interference semiconductor laser device comprising: a body of semiconductor material capable of radiation emission and having opposed first and second facet surfaces from which the radiation is capable of being emitted, said body comprising: a semiconductor substrate having a channel extending along one surface generally parallel with said facet surfaces, said channel being positioned closer to said first facet surface than to said second facet surface; a first cladding layer formed on said one substrate surface having said channel; an active layer formed on said first cladding layer; a second cladding layer formed on said active layer; and a cap layer formed on said second cladding layer; said channel defining an internal reflecting section in said body with a first laser operation area ranging from said first facet surface to said internal reflecting section and a second laser operation area ranging from said second facet surface to said internal reflecting section, said first laser operation area having a length l 1 less than the length l 2 of said second laser operation area; first and second reflectors disposed on said first and second facet surfaces, respectively, said first reflector producing a reflectivity R 1 less than the reflectivity R 2 produced by said second reflector.