Manufacturing method of semiconductor laser with non-absorbing mirror structure

A semiconductor laser device comprising:

• a semiconductive substrate;
• a doublehetero-junction section provided above said substrate, said doublehetero-junction section having first and second cladding layers being opposite to each other in their conductivity type, an active layer sandwiched between said first and second cladding layers, an elongated semiconductive ridge-shaped layer disposed above the second cladding layer and being same as said second cladding layer in its conductivity type;
• said ridge-shaped layer serving as a waveguide channel region to which a current is mainly supplied in an oscillation mode of said laser, and having an output end portion from which an oscillated laser light is externally emitted;
• a current-blocking layer provided on said second cladding layer and said ridge-shaped layer, having an opening defined above a central region of said waveguide channel region, for covering said output end portion of said second cladding layer;
• and
• said active layer including, in a peripheral portion adjacent to said output end portion of said second cladding layer, a specific band gap region having a first energy band gap which is larger than a second energy band gap in a substantially central region of said active layer, whereby self absorption in an oscillated laser light at said output end portion is reduced or prevented.

A semiconductor laser device comprising:

• a semiconductive substrate of N type conductivity;
• a first cladding layer of N type conductivity provided above said substrate;
• an active layer provided on said first cladding layer;
• a second cladding layer of P type conductivity provided on said active layer, said second cladding layer including a waveguide channel region to which a current is mainly supplied in an oscillation mode of said laser, and an output end portion from which an oscillated laser light is externally sent forth;
• a current-blocking layer of N type conductivity provided on said second cladding, having an opening defined above a central region of said waveguide channel region, said current-blocking layer covering said output end portion of said second cladding layer;
• a contact layer of P type conductivity provided on said current blocking layer and said second cladding layer;
• and
• said active layer including, in a peripheral portion adjacent to said output end portion of said second cladding layer, a specific band gap region doped with zinc and having a first energy band gap which is larger than a second energy band gap in a substantially central region of said active layer, whereby self absorption in an oscillated laser light at said output end portion is reduced or prevented.