How does laser work>?

Question

Can you give me the references?

Answer 1

A laser consists of a gain medium inside an optical cavity, with a means to supply energy to the gain medium. The gain medium is a material (gas, liquid, solid or free electrons) with appropriate optical properties. In its simplest form, a cavity consists of two mirrors arranged such that light bounces back and forth, each time passing through the gain medium. Typically, one of the two mirrors, the output coupler, is partially transparent. The output laser beam is emitted through this mirror.

A laser is an electronic-optical device that produces coherent radiation. The term "laser" is an acronym for Light Amplification by Stimulated Emission of Radiation. A typical laser emits light in a narrow, low-divergence beam and with a well-defined wavelength (i.e., monochromatic, corresponding to a particular colour if the laser is operating in the visible spectrum). This is in contrast to a light source such as the incandescent light bulb, which emits into a large solid angle and over a wide spectrum of wavelength.

Answer 2

i m not expert in this, but i do have some references for u.

http://www.howstuffworks.com/laser.htm

http://inventors.about.com/od/lstartinventions/a/laser.htm