Passive waveguide structure with alternating GaInAs/AlInAs layers for mid-infrared optoelectronic devices
View Patent ↗Disclosed is a semiconductor optical emitter having an optical mode and a gain section, the emitter comprising a low loss waveguide structure made of two alternating layers of semiconductor materials A and B, having refractive indexes of Na and Nb, respectively, with an effective index N o of the optical mode in the low loss waveguide between Na and Nb, wherein No is within a 5% error margin of identical to a refractive index of the gain section and wherein the gain section is butt-jointed with the low loss waveguide, and wherein the size and shape of the optical mode(s) in the low loss waveguide and gain section are within a 10% error margin of equal. Desirably, at least one of the semiconductor materials A and B has a sufficiently large band gap that the passive waveguide structure blocks current under a voltage bias of 15 V.
1. A semiconductor optical emitter having an optical mode and a gain section, the emitter comprising a low loss waveguide structure made of alternating layers of at least two semiconductor materials A and B, having refractive indexes of N a and N b , respectively, with an effective index N o of the optical mode in the low loss waveguide between N a and N b ,
wherein a ratio of thicknesses of the materials A and B is selected in order to form the low loss waveguide with the effective index N o that is within a desired error margin of identical to a refractive index of the gain section.
2. The emitter of claim 1 wherein at least one of the semiconductor materials A and B has a sufficiently large band gap that the passive waveguide structure blocks current under a voltage bias of 15 V.
3. The emitter of claim 1 wherein at least one of the semiconductor materials A and B has a sufficiently large band gap that the passive waveguide structure blocks current under a voltage bias of 20 V.
4. The emitter of claim 1 wherein at least one of the semiconductor materials A and B has a sufficiently large band gap that the passive waveguide structure blocks current under a voltage bias of 25 V.
5. The emitter of claim 1 wherein material A is AlInAs and material B is GaInAs.
6. The emitter of claim 5 wherein the AlInAs and the GaInAs are left undoped.
7. The emitter of claim 5 wherein the GaInAs is left undoped and the AlInAs is doped with a deep trap element or elements.
8. The emitter of claim 7 wherein the deep trap element or elements is one, or a combination, of iron and titanium.
9. The emitter of claim 7 wherein the deep trap element is iron.
10. The emitter of claim 7 wherein the deep trap element is Ruthenium.
11. The emitter of claim 1 wherein No is within a 5% error margin of identical to a refractive index of the gain section.
12. The emitter of claim 1 wherein the gain section is butt-jointed with the low loss waveguide.
13. The emitter of claim 1 wherein the size and shape of the optical mode(s) in the low loss waveguide and gain section are within a 10% error margin of equal.