Semiconductor lasers

I am very confused, Could someone explain how a semiconductor laser work please. I know a ruby laser works but i cant figure out how a semiconductor laser works, thanks. :bowdown:

I can't, but he can.

That and wikipedia brings you quite far. It's a good idea to try and find out yourself, then you can ask more specific questions.
Unless you're satisfied with "a semiconductor is basically a diode where the electron-hole pairs in the P-N junction are the population inversion created by a potential across the diode. Add the facets for feedback and you have a cavity with gain."

thanks