Incoming links: Laser pointer
This is by far the most important type of laser commercially, as it can be made relatively cheaply, and it doesn't break easily as it ends up being a single crystal.
Compare them for example to the earlier gas lasers.
This is the type of laser that you would get in a simple laser pointer.
But the real mega aplications are:
- fiber-optic communication, where laser diodes are one of the most commonly used methods to generate the light that goes in the fiber. This makes laser diodes one of the most important inventions of the 20th centure without doubt.
- optical storage. But as of the 2020s its usefulness was much diminished by a combination of solid-state storage + faster Internet due largely to fiber-optic communication. So it is partly a matter of laser diodes beating laser diodes!