VECSELs: Growing the Semiconductor Layers
The superlattice semiconductor material consists of thin layers of materials with differing band gaps.
Cap Layer:
- Prevents Carrier Diffusion
- Reduces Al Oxidation
- Affects Reflection on Upper Surface
- Controls the Length of the Structure
- Forms Micro-Cavity with DBR
Pump Absorption and Gain Region:
- QWs & Al.04GaAs Layers Absorb Pump Light
- InGaAs QWs provide gain
- GaAsP Layers Provide Strain Relief
DBR:
- Provides High Reflector for Laser Cavity
- Prevents Carrier Diffusion
The structures are accurately grown using MOCVD with in-situ optical monitoring.
EMCORE D125 Reactor, Compound Semiconductor Research Laboratory
- In-situ Monitors
- Near Normal Incidence Reflectance
- Emissivity Correcting Pyrometer
- TMAl, TMGa, TMIn, AsH3 and PH3
- Wafer Temp.: 750° / 620°
- Pressure: 60 torr
- Rotation: 1000 rpm
- Growth Rate: 5-10 Å/s
THE VECSEL TEAM
Points of Contact:
| W. J. Alford | Andy Allerman | Ron Allman | ||
| Mike Bannis | Mary Crawford | Weng Chow | ||
| Peter Esherick | Art Fischer | T. D. Raymond | ||
| Darwin Serkland | Arlee Smith | Channy Wong |
Related Links:
VECSEL: The Other Surface Emitting Semiconductor Laser