Question

How do laser pointers work?

Answer 1

Laser pointers generate light in a laser diode and then put the laser beam through one or more mirrors.

Explanation:

Laser light is produced when you bounce light back and forth between two mirrors, in certain special mediums.

See:
Minute Physics: How lasers work

Here is the inside of a typical inexpensive red laser pointer:

And here is the inside of an expensive, green laser pointer:

In general, you generate the laser light in the Laser Diode (powered by batteries) and then put the light through one or more lenses to make the beam wider.