What are laser lights made of? How do they work?

This FAQ is probably best answered in a general electronics forum such as VK2TIP Q&A rather than here in the ham radio wiki, but some very brief info follows

Lasers are narrow beams of coherent light. Laser light displays are often produced by laser beams that are controlled by music. The mechanism is known as a laser scanner, which is in effect a series of mirrors mounted on galvanometers. In a music controlled system, the deflection of the galvanometer is controlled by the music, and determines the angle of the mirror and hence the direction of the beam.

This link How stuff works - lasers will give you more information.

In Ham radio, lasers can be used for communication. This wiki page :Optical communications has some more info.

Tim R VK4YEH