What is needed to build a laser?
two fully reflective mirrors
two partially reflective mirrors
a partially reflective mirror and a fully reflective mirror
a concave lens and a convex lens that are fully reflective
None of the above options are complete lists of what is needed to build a laser. Here are some of the necessary components:
- A gain medium (e.g. a crystal or gas) that can amplify light through stimulated emission.
- An energy source (e.g. electricity or light) that can pump energy into the gain medium to create a population inversion.
- A cavity (e.g. two mirrors facing each other) that can trap the light and reflect it back and forth through the gain medium to stimulate more emission.
- Optics (e.g. lenses or prisms) that can shape and direct the laser beam.
- Control electronics or software (e.g. to regulate the energy input and output or to modulate the beam).