Semiconductor laser element with optical waveguide layer having increased thickness
View Patent ↗In a semiconductor laser element: a lower cladding layer of In 0.49 (Al x1 Ga 1-x1 ) 0.51 (x2<x1<1) of a first conductive type which lattice-matches with GaAs; a lower optical waveguide layer of In 0.49 (Al x2 Ga 1-x2 ) 0.51 P (0<x2<x1) which lattice-matches with GaAs; an active layer; an upper optical waveguide layer of In 0.49 (Al x2 Ga 1-x2 ) 0.51 P (0<x2<x1) which lattice-matches with GaAs; and an upper cladding layer of In 0.49 (Al x1 Ga 1-x1 ) 0.51 P (x2<x1<1) of a second conductive type which lattice-matches with GaAs are formed in this order on a substrate of GaAs. The total thickness of the lower optical waveguide layer, the active layer, and the upper optical waveguide layer is 0.30 micrometers or greater.
1. A semiconductor laser element comprising:
a substrate made of GaAs;
a lower cladding layer formed above said substrate and made of In 0.49 (Al x1 Ga 1-x1 ) 0.51 P of a first conductive type which lattice-matches with GaAs, where x2<x1<1;
a lower optical waveguide layer formed above said lower cladding layer and made of In 0.49 (Al x2 Ga 1-x2 ) 0.51 P which lattice-matches with GaAs, where 0<x2<x1;
a strained active layer formed above said lower optical waveguide layer;
an upper optical waveguide layer formed above said active layer and made of In 0.49 (Al x2 Ga 1-x2 ) 0.51 P which lattice-matches with GaAs, where 0<x2<x1; and
an upper cladding layer formed above said upper optical waveguide layer and made of In 0.49 (Al x1 Ga 1-x1 ) 0.51 P of a second conductive type which lattice-matches with GaAs, where x2<x1<1;
wherein a total thickness of said lower optical waveguide layer, said active layer, and said upper optical waveguide layer is 0.30 micrometers or greater; and
wherein at least one of said lower cladding layer and said upper cladding layer has a thickness of 0.6 micrometers or smaller.
2. A semiconductor laser element according to claim 1 , wherein said total thickness is 0.35 to 0.6 micrometers.
3. A semiconductor laser element according to claim 1 , wherein at least one of said lower cladding layer and said upper cladding layer has a thickness of 0.8 micrometers or smaller.
4. A semiconductor laser element according to claim 2 , wherein at least one of said lower cladding layer and said upper cladding layer has a thickness of 0.8 micrometers or smaller.
5. A semiconductor laser element according to claim 2 , wherein at least one of said lower cladding layer and sald upper cladding layer has a thickness of 0.6 micrometers or smaller.
6. A semiconductor laser element according to claim 1 , wherein said active layer is made of In 0.49 (Al x3 Ga 1-x3 ) 0.51 P, 0≦x3<x2, and said semiconductor laser element has an oscillation wavelength of 620 to 680 nm.
7. A semiconductor laser element according to claim 2 , wherein said active layer is made of In 0.49 (Al x3 Ga 1-x3 ) 0.51 P 0≦x3≦x2, and said semiconductor laser element has an oscillation wavelength of 620 to 680 nm.
8. A semiconductor laser element according to claim 3 , wherein said active layer is made of In 0.49 (Al x3 Ga 1-x3 ) 0.51 P, 0≦x3<x2, and said semiconductor laser element has an oscillation wavelength of 620 to 680 nm.
9. A semiconductor laser element according to claim 4 , wherein said active layer is made of In 0.49 (Al x3 Ga 1-x3 ) 0.51 P, 0≦x3<x2, and said semiconductor laser element has an oscillation wavelength of 620 to 680 nm.
10. A semiconductor laser element according to claim 1 , wherein said active layer is made of In 0.49 (Al x3 Ga 1-x3 ) 0.51 P, 0≦x3<x2, and said semiconductor laser element has an oscillation wavelength of 620 to 680 nm.
11. A semiconductor laser element according to claim 5 , wherein said active layer is made of In 0.49 (Al x3 Ga 1-x3 ) 0.51 P, 0≦x3<x2, and said semiconductor laser element has an oscillation wavelength of 620 to 680 nm.