Asymmetric waveguide GaInAs laser diode
View Patent ↗A laser diode is provided. The laser diode has a structure in which reflective index of an n-cladding layer formed on a first face of the active layer is higher than that of a p-cladding layer formed on a second face. This asymmetric waveguide structure suppresses extension of field into the p-cladding layer thus reducing free carrier absorption in the p-cladding layer.
1. A laser diode comprising:
an active layer having first and second faces;
an n-cladding layer disposed on the first face of the active layer;
a p-cladding layer disposed on the second face of the active layer; and
a substrate that supports a stacked structure including the active layer and n- and p-cladding layers,
wherein the refractive index of the p-cladding layer is lower than that of the n-cladding layer,
wherein the doping concentration of the p-cladding layer varies from one portion to another and increases moving toward the active layer.
2. The laser diode of claim 1 , wherein the active layer contains GaInNAs/GaAs quantum wells.
3. The laser diode of claim 2 , wherein the p-cladding layer is thicker than the n-cladding layer.
4. The laser diode of claim 2 , wherein the p-cladding layer is thicker than the n-cladding layer.
5. The laser diode of claim 1 , wherein the active layer contains GaInNAs/GaNAs quantum wells.
6. The laser diode of claim 5 , wherein the p-cladding layer is thicker than the n-cladding layer.
7. The laser diode of claim 5 , wherein the p-cladding layer is thicker than the n-cladding layer.
8. The laser diode of claim 1 , wherein the p-cladding layer is thicker than the n-cladding layer.
9. The laser diode of claim 1 , wherein the p-cladding layer is thicker than the n-cladding layer.