Vertically coupled large area amplifier
A monolithic light amplification system including: an un-doped waveguide; a ridge waveguide positioned over the un-doped waveguide; and, at least a doped layer between the un-doped waveguide and ridge waveguide; wherein, the un-doped waveguide and ridge waveguide cooperate to amplify light input to the un-doped waveguide.
1. A monolithic light amplification system comprising:
an un-doped waveguide region devoid of quantum well structure;
a ridge waveguide region positioned over said un-doped waveguide region;
at least one quantum well structure formed only in said ridge waveguide region; and
at least a doped layer between said un-doped waveguide region and said ridge waveguide region; wherein, said un-doped waveguide region and said ridge waveguide region cooperate to amplify light present in a fundamental optical mode supported by the combination of said ridge waveguide region and said un-doped waveguide region.
2. The system of claim 1 , wherein said un-doped waveguide region comprises AlGaAs.
3. The system of claim 1 , wherein said AlGaAs of said un-doped waveguide region has an Al content of about 0.21%.
4. The system of claim 3 , wherein said ridge waveguide region comprises InGaAs.
5. The system of claim 2 , wherein said doped layer comprises n-AlGaAs.
6. The system of claim 5 , wherein said n-AlGaAs of said doped layer has an Al content of between about 0.3% and 0.25%.
7. The system of claim 5 , wherein said n-AlGaAs is doped on the order of 1×10 18 cm 31 3 .
8. The system of claim 1 , further comprising a cladding positioned over said ridge waveguide region.
9. The system of claim 1 , further comprising a p-cladding positioned over said ridge waveguide region.
10. The system of claim 9 , wherein said p-cladding comprises p-AlGaAs.
11. The system of claim 10 , wherein said at least one doped layer comprises n-AlGaAs.
12. The system of claim 11 , wherein said cladding and said doped layer are doped.
13. The system of claim 11 , wherein said cladding and at least one doped layer are doped on the order of 1×10 18 cm −3 .
14. The system of claim 1 , further comprising input and output facets optically coupled to said un-doped waveguide region.
15. The system of claim 14 , wherein said un-doped waveguide region provides for an amplified optical mode well suited for being coupled to an optical fiber via said output facet.