Question: how are lazars made?

Jesse Dykes answered on 19 Mar 2020:

Lasers are made out of three things. A gain medium, which often is some kind of crystal or glass, or sometimes gas. A cavity, which is where the gain medium is put inbetween a pair of mirrors facing each other. And a pump source, a way to get energy into the gain medium. This could be electricity, a bright torch, or even another laser. The idea is you put energy into the gain medium and it starts emitting light in all directions. Some light bounces back and forth off the mirrors and survives while the other light hits the container and gets absorbed. Then you let the light out of one of the mirrors and you get a laser beam