What are the basics of laser anatomy?

Lasers consist of three components:

• An external pump source. This component guides external energy to the laser.
• The active laser medium. The active laser medium is located on the inside of the laser. Depending on the design, the laser medium can consist of a gas mixture (CO2 laser), of a crystal body (YAG laser), or glass fibers (fiber laser). When energy is fed to the laser medium through the pump, it emits energy in the form of radiation.
• The resonator. The active laser medium is located between two mirrors, the “resonator.” One of these mirrors is a one-way mirror. The radiation of the active laser medium is amplified in the resonator. At the same time, only a certain radiation can leave the resonator through the one-way mirror. This bundled radiation is the laser radiation.

-Josh Stephens, Trotec Laser