Optical semiconductor device and optical semiconductor in tegrated circuit

A semiconductor laser comprising:

• a gain region having wavelength selectivity;
• a propagating region optically coupled to said gain region, having a material with an effective refractive index whose temperature dependence differs from that of said gain region, and having no gain nor wavelength selectivity;
• and
• a reflection region that reflects light propagated through said propagating region, and has no gain.

A semiconductor laser comprising:

• a gain region having wavelength selectivity;
• a propagating region optically coupled to said gain region, having a structure with an effective refractive index whose temperature dependence differs from that of said gain region, and having no gain nor wavelength selectivity;
• and
• a reflection region that reflects light propagated through said propagating region, and has no gain.

A semiconductor laser comprising:

• a first gain region having wavelength selectivity;
• a propagating region optically coupled to said first gain region, having a material with an effective refractive index whose temperature dependence differs from that of said gain region, and having no gain nor wavelength selectivity;
• and
• a second gain region optically coupled to said propagating region, and having wavelength selectivity.

A semiconductor laser comprising:

• a first gain region having wavelength selectivity;
• a propagating region optically coupled to said first gain region, having a structure with an effective refractive index whose temperature dependence differs from that of said gain region, and having no gain nor wavelength selectivity;
• and
• a second gain region optically coupled to said propagating region, and having wavelength selectivity.

A semiconductor laser comprising:

• a semiconductor substrate;
• an active layer formed on said semiconductor substrate, and having a distributed reflection structure;
• a cladding layer formed on said active layer;
• a removed region from which part of said active layer and said cladding layer is removed;
• and
• a temperature compensation layer buried in said removed region, and having an effective refractive index whose temperature dependence differs from that of said active layer.

A semiconductor laser comprising:

• a semiconductor substrate;
• a distributed Bragg reflection layer stacked on said semiconductor substrate;
• an active layer stacked on said distributed Bragg reflection layer, and having a distributed reflection structure;
• a temperature compensation layer stacked on said active layer, and having an effective refractive index whose temperature dependence differs from that of said active layer;
• and
• a reflection layer stacked on said temperature compensation layer.

A semiconductor laser comprising:

• a semiconductor substrate;
• an active layer formed on said semiconductor substrate, and having a distributed reflection structure;
• a cladding layer formed on said active layer, and having an inclined surface at an end of said active layer;
• and
• a temperature compensation layer formed on said cladding layer, and having an effective refractive index whose temperature dependence differs from that of said active layer.