Semiconductor laser device

A semiconductor laser device comprising:

• a semiconductor substrate;
• a dielectric film formed on said semiconductor substrate;
• a channel formed in said dielectric film, said channel reaching said substrate;
• a mesa stripe having a multilayer structure formed on said substrate within said channel, and said multilayer structure including an active layer;
• and
• a burying layer covering the side faces of said multilayer structure;
• wherein the main surface of said substrate is a (100) plane, said channel is oriented along the <011>
• direction, said side faces of said multilayer structure are facets of {111} planes, said multilayer structure comprises a lower portion including an active layer and an upper portion including a semiconductor layer having a refractive index smaller than that of said active layer, and said semiconductor layer covers the side faces of said active layer.

A semiconductor laser device comprising:

• a semiconductor substrate;
• a channel formed on said semiconductor substrate;
• a mesa stripe having a multilayer structure formed on said substrate within said channel, and said multilayer structure including an active layer;
• and
• a burying layer covering the said multilayer structure;
• wherein the main surface of said substrate is a (100) plane, said channel is oriented along the <011>
• direction, and said side face of said multilayer structure are facets of {111} planes.

A semiconductor laser device comprising:

• a semiconductor substrate;
• a stripe-like ridge structure formed on said semiconductor substrate;
• a first multilayer structure, including a first active region, formed on the upper face of said ridge structure;
• a second multilayer structure, including a second active region, formed on the one side face of said ridge structure;
• a third multilayer structure, including a third active region, formed on the other side face of said ridge structure;
• a burying layer covering said first, second, and third multilayer structures;
• a first electrode, a second electrode, and a third electrode formed on said burying layer;
• a first diffusion region formed in said burying layer, and electrically connecting said first multilayer structure to said first electrode;
• a second diffusion region, formed in said burying layer, and electrically connecting said second multilayer structure to said second electrode;
• and
• a third diffusion region, formed in said burying layer, and electrically connecting said third multilayer structure to said third electrode.

A semiconductor laser device comprising:

• a semiconductor substrate;
• a terrace structure formed on said semiconductor substrate;
• a first multilayer structure, including a first active region, formed on the upper level of said terrace structure;
• a second multilayer structure, including a second active region, formed on the side face of the escarpment of said terrace structure;
• a burying layer covering said first and second multilayer structures;
• a first electrode, and a second electrode formed on said burying layer;
• a first diffusion region formed in said burying layer, and electrically connecting said first multilayer structure to said first electrode;
• and
• a second diffusion region, formed in said burying layer, and electrically connecting said second multilayer structure to said second electrode.

A distributed feedback type semiconductor laser device comprising:

• a semiconductor substrate;
• a mesa stripe having a multilayer structure and formed on said substrate, said multilayer structure including an active layer;
• a light guide layer formed on the side face of said multilayer structure, on which a diffraction is ruled;
• and
• a burying layer covering said light guide layer;
• wherein the main surface of said substrate is a (100) plane, said channel is oriented along the <011>
• direction, and said side faces of said multilayer structure are facets of {111} planes.