- #1
Karl330
- 7
- 1
Hello I am struggling to understand the concept of Quantum cascade lasers. I am doing research on a 20 period In0.33Ga0.67As (3.1 nm)/Al0.90In0.10As (7.2 nm) superlattice and would like to fully understand how a quantum cascade laser works. I also have not taken quantum mechanics yet so I might be a little slow to understand. Here is the question
I keep seeing images like this for a quantum cascade laser. Why does the band energy (y-axis) go down for every layer as shown here and what do the squiggly lines mean (I know these are the electron wavefunctions but I'm not entirely sure I get what is going on)?
In addition to this how does population inversion happen with each active layer for each electron to get to the highest energy level. Is it some type of pumping from phonons?
Here is what a laser physics book says
The electron leaves the lowest subband by spatial escape to the neighboring conducting region.
I keep seeing images like this for a quantum cascade laser. Why does the band energy (y-axis) go down for every layer as shown here and what do the squiggly lines mean (I know these are the electron wavefunctions but I'm not entirely sure I get what is going on)?
In addition to this how does population inversion happen with each active layer for each electron to get to the highest energy level. Is it some type of pumping from phonons?
Here is what a laser physics book says
The electron leaves the lowest subband by spatial escape to the neighboring conducting region.