Buried lateral index guided lasers and lasers with lateral current blocking layers
View Patent ↗A method and structure for laterally index guiding is described. In the method, lateral areas around the a semiconductor device active region are exposed to hydrogen. The hydrogen adjusts the index of refraction surrounding the laser active region helping to confine both the electrical carriers and the generated light to the laser active region.
1. A semiconductor structure to output light comprising:
a semiconductor layer including an active region that includes at least Gallium, Arsenide and Nitride; and,
a laterally adjacent region including hydrogen induced bandgap shifted semiconductor material formed alongside the active region, the bandgap shifted semiconductor material positioned to improve lateral optical confinement in the active region.
2. The semiconductor structure of claim 1 wherein the semiconductor structure is a laser.
3. The semiconductor structure of claim 1 wherein the semiconductor structure is a light emitting diode.
4. The semiconductor structure of claim 1 wherein the hydrogen concentration in the laterally adjacent region causes a bandgap shift of between 1 meV and 100 meV.
5. The semiconductor structure of claim 1 wherein the semiconductor structure outputs light at a wavelength between 1.0 μm and 1.7 μm.
6. The semiconductor structure of claim 1 further comprising:
aluminum-gallium-arsenide cladding layers deposited over the semiconductor active region, the cladding layers to help guide the optical modes propagating in the semiconductor active region.
7. The semiconductor structure of claim 6 further comprising an electrical contact coupled such that electrical energy is provided to the structure resulting in output light having a wavelength between 1.0 μm and 1.7 μm.
8. The semiconductor laser of claim 2 wherein a facet of the semiconductor laser is made from hydrogenated InGaAsN active material.
9. The semiconductor structure of claim 1 further comprising:
depositing a GaAsN waveguide spacer materials over the semiconductor active layer.
10. The semiconductor structure of claim 9 wherein the GaAsN waveguide spacer material is hydrogenated in the region directly above the laterally adjacent hydrogen induced bandgap shifted semiconductor material.
11. The semiconductor structure of claim 1 wherein the active region includes InGaAsN.
12. The semiconductor structure of claim 1 wherein the active region includes AIGaAsN.
13. The semiconductor structure of claim 1 wherein the laterally adjacent region surrounds the active region to form an optical aperture.
14. The semiconductor structure of claim 13 wherein the semiconductor structure is a VCSEL.
15. The semiconductor structure of claim 14 wherein the optical aperture is asymmetric, the asymmetric shape stabilizes the polarization output by the VCSEL.
16. A semiconductor laser structure comprising:
a substrate;
a cladding layer;
a semiconductor layer including an active region and a laterally adjacent semiconductor region including hydrogen induced bandgap shifted semiconductor material formed alongside the active region, the bandgap shifted semiconductor material positioned to improve lateral carrier confinement;
a hydrogenated facet coupled to the active region, the hydrogen in the facet to shift a bandage of the facet;
a second cladding layer; and,
a contact to provide current to the active region.
17. The semiconductor laser structure of claim 16 wherein an energy difference between the active region and the bandgap shifted semiconductor material provides lateral confinement of carriers.