User:Dave3457/Sandbox/Polarizer before
From Wikipedia, the free encyclopedia
For the photographic filter, see Polarizing filter (Photography).
A polarizer is a device that converts a beam of electromagnetic waves (light) of undefined or mixed polarization into a beam with well-defined polarization. Polarizers are used in many optical techniques and instruments, and polarizing filters find applications in photography and liquid crystal display technology.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Polarizer_Through_Glass.jpg/640px-Polarizer_Through_Glass.jpg)
Polarizers can be divided into two general categories: absorptive polarizers, where the unwanted polarization states are absorbed by the device, and beam-splitting polarizers, where the unpolarized beam is split into two beams with opposite polarization states.