As light travels, it normally vibrates in all directions at right angles to the line of transmission. If a strongly absorbing crystal, e.g. polaroid or tourmaline, is placed in the light path, the rays are strongly absorbed in all directions except one, and the rays of light that emerge are confined to this one plane of vibration; i.e. the light is ‘plane polarized’. Polarization may also result from double refraction (see nicol prism) or reflection.
Subjects: Earth Sciences and Geography.