Quantum Well Lasers

1
Quantum Well Lasers
Material gain ?2500cm-1, deff250nm
Modal gain
da50nm?
Too high
We need maybe only da 5nm
2
Electronic States in 3D
Schroedinger equation
Probability density
Charge density
3D-semiconductor
Solution
Energy
3
Electronic States in quantum wells
CEc-Ecm
4
Separation of variables
5
Envelope wave functions
where Uc(zltda/2)0,Uc(zgtda/2) ?Vc
For infinite ?Vc
In plane motion
6
2D-density of states
7
Gain coefficient
?(?)
? (?)
8
Gain coefficient
9
Separate confinement heterostructures