Long wavelength VCSEL bottom mirror
View Patent ↗A vertical cavity surface emitting laser having an InP substrate and a lower mirror stack comprised of a plurality of alternating layers of AlPSb and GaPSb over the InP substrate. An InP spacer is over the lower mirror stack. An active region is over the InP spacer, and a tunnel junction is over the active region. Then a top mirror structure comprised of a low-temperature formed first GaAs buffer layer, a high-temperature formed second GaAs seed layer, an insulating structure having an opening, and a GaAs/Al(Ga)As mirror stack that is grown by lateral epitaxial overgrowth.
1. A vertical cavity surface emitting laser, comprising:
an InP substrate,
a lower minor stack comprised of a plurality of alternating layers of AlPSb and GaPSb over thc InP substrate:
an active region over the lower mirror stack;
a top mirror stack over the active region, the top mirror stack comprising:
a first GaAs buffer layer;
a second GaAs seed layer over the first GaAs buffer layer; and
a plurality of alternating layers of GaAs and Al(Ga)As over the second GaAs seed layer,
wherein the top mirror stack is grown by MOCVD.
2. A vertical cavity surface emitting laser according to claim 1 , wherein the alternating layers of AlPSb and GaPSb are grown by MOCVD.
3. A vertical cavity surface emitting laser according to claim 1 , further including a lower InP spacer over the lower mirror stack.
4. A vertical cavity surface emitting laser according to claim 3 , wherein the lower InP spacer is grown by MOCVD.
5. A vertical cavity surface emitting laser according to claim 1 , wherein the active region includes AlInGaAs or InGaAsP.
6. A vertical cavity surface emitting laser according to claim 5 , further including a tunnel junction over the active region.
7. A vertical cavity surface emitting laser according to claim 6 , wherein the tunnel junction includes an MOCVD-grown GaAs (1-x) Sb x layer.
8. A vertical cavity surface emitting laser according to claim 1 , wherein the first GaAs buffer layer is grown by MOCYD between 400° C. and 450° C.
9. A vertical cavity surface emitting laser according to claim 1 , wherein the second GaAs seed layer is grown by MOCVD at about 600° C.
10. A vertical cavity surface emitting laser according to claim 9 , further including an insulating structure on the second GaAs seed layer, wherein the insulating structure includes an opening.
11. A vertical cavity surface emitting laser according to claim 9 , wherein tho GaAs/Al(Ga)As top mirror stack is grown by lateral epitaxcial overgrowth from the second GaAs seed layer.
12. A vertical cavity surface emitting laser, comprising:
an InP substrate;
a lower mirror stack comprised of a plurality of alternating layers of AlGalnAs and AlInAs over the lnP substrate;
an active region over the lower mirror stack;
a ton mirror stack over the active region, the top mirror stack comprising;
a first GaAs buffer layer;
a second GaAs secd layer over the first GaAs buffer layer; and
a plurality of alternating layers of GaAs and AI(Ga)As over the second GaAs seed layer,
wherein the top mirror stack is grown by MOCVD.
13. A vertical cavity surface emitting laser according to claim 12 , further including a lower InP spacer over the lower mirror stack.
14. A vertical cavity surface emitting laser according to claim 13 , wherein the lower InP spacer is grown by MOCVD.
15. A vertical cavity surface emitting laser according to claim 12 , wherein the active region includes AlInGaAs or InGaAsP.
16. A vertical cavity surface emitting laser according to claim 15 , further including a tunnel junction over the active region.
17. A vertical cavity surface emitting laser according to claim 16 , wherein the tunnel junction includes a MOCVD-grown GaAs (1-x) Sb x layer.
18. vertical cavity surface emitting laser according to claim 12 , wherein the first GaAs buffer layer is grown by MOCVD between 400° C. and 450° C., and wherein the second GaAs seed layer is grown by MOCVD at about 600° C.
19. A vertical cavity surface emitting laser according to claim 18 , further including an insulating structure on the second GaAs seed layer, wherein the insulating structure includes an opening.
20. A vertical cavity surface emitting laser according to claim 18 , wherein the GaAs/Al(Ga)As top mirror stack is grown by lateral epitaxial overgrowth from the second GaAs iced layer.
21. A vertical cavity surface emitting laser according to claim 1 wherein the first GaAs buffer layer is grown by MOCVD over 400° C.
22. A vertical cavity surface emitting laser according to claim 12 wherein the first GaAs buffer layer is grown by MOCVD over 400° C. and thc second GaAs seed layer is grown by MOCVD at about 600° C.