Buried heterostructure semiconductor laser fabricated on a p-type substrate

A buried heterostructure semiconductor laser formed on a semiconductor laser formed on a semiconductor substrate having a p-type conductivity comprising:

• a striped-mesa shaped region elongated in a lasing cavity direction and including an active layer region;
• a first p-type semiconductor layer, a first semiconductor layer, a first n-type semiconductor layer, a second p-type semiconductor layer and a second semiconductor layer sequentially laminated on both sides of said striped-mesa shaped region;
• said first semiconductor layer and said second semiconductor layer both having a band gap smaller than the band gap of any of said first p-type semiconductor layer, said first n-type semiconductor layer, and said second p-type semiconductor layer;
• and
• a second n-type semiconductor layer covering the surfaces of said active layer region and said second semiconductor layer.

A buried heterostructure semiconductor laser formed on a semiconductor substrate having a p-type conductivity comprising:

• an active layer region having a striped-mesa shape elongated in a lasing cavity direction;
• a pair of channels having a depth reaching a first p-type semiconductor layer and formed on both sides of said active layer region;
• a second p-type semiconductor layer, a first semiconductor layer, a first n-type semiconductor layer, a third p-type semiconductor layer, and a second semiconductor layer sequentially laminated within said pair of channels to bury said pair of channels;
• said first semiconductor layer and said second semiconductor layer each having a band gap smaller than the band gap of any of said second p-type semiconductor layer, said first n-type semiconductor layer, and said third p-type semiconductor layer;
• and
• a second n-type semiconductor layer covering the surfaces of said active layer region said second semiconductor layer, wherein said second p-type semiconductor layer is in direction contact with said first n-type semiconductor layer at portions adjacent to said active layer region, and said third p-type semiconductor layer is in direct contact with said second n-type semiconductor layer at portions adjacent to said active layer region.

A buried heterostructure semiconductor laser formed on a semiconductor substrate having a p-type conductivity comprising:

• a striped-mesa shaped region elongated in a lasing cavity direction and including an active layer region;
• a first p-type semiconductor layer, a first semiconductor layer, a first n-type semiconductor layer, a second p-type semiconductor layer and a second semiconductor layer sequentially laminated on both sides of said striped-mesa shaped region;
• said first semiconductor layer and said second semiconductor layer both having a band gap smaller than the band gap of any of said first p-type semiconductor layer, said first n-type semiconductor layer, and said second p-type semiconductor layer;
• and
• a second n-type semiconductor layer covering the surfaces of said active layer region and said second semiconductor layer, wherein said first p-type semiconductor layer is in direct contact with said first n-type semiconductor layer at portions adjacent to said active layer region, and said second p-type semiconductor layer is in direct contact with said second n-type semiconductor layer at portions adjacent to said active layer region.