Semiconductor laser element
A semiconductor laser element may include an n-type clad layer; an n-type waveguide layer adjacent to the n-type clad layer; an n-type carrier blocking layer adjacent to the n-type waveguide layer; an active layer; and a p-type clad layer adjacent to the active layer. The n-type clad layer may have a bandgap width greater than a bandgap width of the n-type waveguide layer. The n-type carrier blocking layer may have a bandgap width greater than or equal to bandgap widths of the first and second barrier layers. The p-type clad layer may have a bandgap width greater than the bandgap widths of the first and second barrier layers and the bandgap width of the n-type waveguide layer. The active layer may include a quantum well layer and barrier layers.
1. A semiconductor laser element, comprising:
an active layer comprising a quantum well layer and barrier layers;
an n-type carrier blocking layer adjacent to the active layer;
an n-type waveguide layer adjacent to the n-type carrier blocking layer on a side opposite to the active layer;
an n-type clad layer adjacent to the n-type waveguide layer on the side opposite to the active layer; and
a p-type clad layer contiguous to the active layer on a side opposite to the n-type carrier blocking layer;
wherein the n-type clad layer has a bandgap width greater than a bandgap width of the n-type waveguide layer,
wherein the n-type carrier blocking layer has a bandgap width greater than or equal to bandgap widths of the barrier layers, and
wherein the p-type clad layer has a bandgap width greater than the bandgap widths of the barrier layers and the bandgap width of the n-type waveguide layer.
2. The semiconductor laser element of claim 1 , wherein a refractive index of the n-type clad layer is greater than a refractive index of the p-type clad layer.
3. The semiconductor laser element of claim 1 , wherein the n-type carrier blocking layer has a layer thickness T of 10 nm≦T≦30 nm.
4. The semiconductor laser element of claim 2 , wherein the n-type carrier blocking layer has a layer thickness T of 10 nm≦T≦30 nm.
5. The semiconductor laser element of claim 1 , wherein the n-type carrier blocking layer has a layer thickness T of greater than 10 nm.
6. The semiconductor laser element of claim 1 , wherein the n-type carrier blocking layer has a layer thickness T of less than 30 nm.
7. The semiconductor laser element of claim 1 , wherein the bandgap width of the n-type carrier blocking layer is greater than the bandgap widths of the barrier layers.
8. The semiconductor laser element of claim 1 , wherein the bandgap width of the n-type carrier blocking layer is greater than the bandgap width of the n-type clad layer.
9. The semiconductor laser element of claim 1 , wherein the bandgap width of the n-type carrier blocking layer is greater than the bandgap width of the n-type waveguide layer.
10. A semiconductor laser element, comprising:
an n-type clad layer;
an n-type waveguide layer adjacent to the n-type clad layer;
an n-type carrier blocking layer adjacent to the n-type waveguide layer;
a first barrier layer adjacent to the n-type carrier blocking layer;
a quantum well layer adjacent to the first barrier layer;
a second barrier layer adjacent to the quantum well layer; and
a p-type clad layer contiguous to the second barrier layer;
wherein the n-type clad layer has a bandgap width greater than a bandgap width of the n-type waveguide layer,
wherein the n-type carrier blocking layer has a bandgap width greater than or equal to bandgap widths of the first and second barrier layers, and
wherein the p-type clad layer has a bandgap width greater than the bandgap widths of the first and second barrier layers and the bandgap width of the n-type waveguide layer.
11. The semiconductor laser element of claim 10 , wherein the bandgap width of the first barrier layer is equal to the bandgap width of the second barrier layer.
12. The semiconductor laser element of claim 10 , wherein the bandgap width of the n-type carrier blocking layer is greater than the bandgap widths of the first and second barrier layers.
13. The semiconductor laser element of claim 10 , wherein the bandgap width of the n-type carrier blocking layer is greater than the bandgap width of the n-type clad layer.
14. The semiconductor laser element of claim 10 , wherein the bandgap width of the n-type carrier blocking layer is greater than the bandgap width of the n-type waveguide layer.
15. The semiconductor laser element of claim 1 , wherein the active layer is formed of InGaAs/AlGaAs.
16. The semiconductor laser element of claim 10 , wherein the quantum well layer is formed of InGaAs/AlGaAs,
wherein the first barrier layer is formed of InGaAs/AlGaAs, and
wherein the second barrier layer is formed of InGaAs/AlGaAs.