VCSEL structure insensitive to mobile hydrogen
View Patent ↗An active region of a VCSEL at one (i.e., n doped) end having an expanded effectively undoped region, and another (i.e., p doped) end having a significantly doped region up to or even including a portion of the active region. A previous way had heavy doping of the n and p doped regions up to the active region, at least close to it or even partially into it.
1. A vertical cavity surface emitting laser structure comprising:
a first mirror;
a second mirror;
an active region situated between the first mirror and the second mirror;
a first spacer situated between the first mirror and the active region;
a second spacer situated between the second mirror and the active region; and
wherein at least a first portion of the first spacer adjacent to the active region has a first doping level, and at least a first portion of the second spacer adjacent to the active region has a second doping level, wherein the first doping level is greater than the second doping level; and
the second spacer includes a second portion that is further away from the active region than the first portion of the second spacer, the second portion of the second spacer being more heavily doped than the first portion of the second spacer.
2. A vertical cavity surface emitting laser structure according to claim 1 wherein the second doping level is undoped.
3. A vertical cavity surface emitting laser structure according to claim 2 wherein the first doping level is highly or moderately doped.
4. A vertical cavity surface emitting laser structure according to claim 1 wherein the first spacer includes a second portion that is further away from the active region than the first portion of the first spacer, the second portion of the first spacer being more heavily doped than the first portion of the first spacer.
5. A vertical cavity surface emitting laser structure according to claim 1 further comprising an abrupt doping level transition from the first doping level at or near the active region.
6. A vertical cavity surface emitting laser structure according to claim 1 further comprising a gradual doping level transition from the first doping level to at or near the active region.
7. An optoelectronic device comprising:
a first mirror;
a second mirror;
an active region situated between said first and second mirrors;
a first region adjacent to a first side of the active region, the first region being doped;
a second region adjacent to a second side of the active region, the second region being undoped; and
a third region adjacent to the second region, but not in between the first region and the second region, that includes a dopant of a first type.
8. An optoelectronic device according to claim 7 wherein the active region includes a dopant of a second type.
9. An optoelectronic device according to claim 7 wherein the active region is undoped or substantially undoped.
10. An optoelectronic device according to claim 7 wherein the second region has a thickness and an aluminum concentration, wherein the thickness of the second region is set depending on the aluminum concentration.
11. An optoelectronic device according to claim 10 wherein the second region has a thickness of 10 nm or less.
12. An optoelectronic device according to claim 7 wherein at least part of the first region is heavily doped.
13. An optoelectronic device comprising:
a lower mirror;
an upper mirror;
an active region situated between said lower and said upper mirror;
a moderately or heavily doped region adjacent the upper side of the active region;
an undoped region adjacent the lower side of the active region; and
a moderately or heavily doped region adjacent the lower side of the undoped region.
14. An optoelectronic device according to claim 13 wherein the doping level of the moderately or heavily doped region that is adjacent the upper side of the active region increased away from the active region.
15. An optoelectronic device according to claim 13 wherein the moderately or heavily doped region adjacent the upper side of the active region is doped a first doping type, and the moderately or heavily doped region adjacent the lower side of the undoped region is doped a second doping type.
16. An optoelectronic device according to claim 13 wherein the moderately or heavily doped region that is adjacent the lower side of the undoped region does not extend into the active region.
17. An optoelectronic device according to claim 13 further comprising:
a more heavily doped region adjacent the lower side of the moderately or heavily doped region that is adjacent the lower side of the undoped region.
18. An optoelectronic device comprising:
a first mirror;
a second mirror;
an active region situated between said first and second mirrors, the active region having active energy bands;
the optoelectronic device having a doping profile, wherein the doping profile includes a first moderately or heavily doped region adjacent to a first side of the active region; a low or undoped region adjacent to a second side of the active region; and a second moderately or heavily doped region adjacent to the low or undoped region, but not in between the first moderately or heavily doped region and the low or undoped region.
19. An optoelectronic device according to claim 18 wherein the first moderately or heavily doped region is of a first type, and the second moderately or heavily doped region is of a second type.
20. An optoelectronic device according to claim 19 wherein the active region is doped with a dopant of the first type.
21. An optoelectronic device according to claim 19 wherein the active region is undoped.