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It
seems that it is easier to linearly polarize light than
completely scramble it. Complete scrambling or depolarization means that
azimuth and phase of the light beam is random at any instant. We make
monochromatic as well polychromatic depolarizers from crystals of calcite,
quartz and magnesium fluoride.
Monochromatic
scramblers which are designed for use with a single wavelength or a narrow
spectrum of light are of single or double wedge type. The wedge shape
causes a slight doubling effect and may be unsuitable for imaging systems.
These must be oriented at 45 degrees to the plane of polarization of
incoming light.
Polychromatic
scramblers are used to depolarize a wide bandwidth at one time. These are
of single plate multi order or double plate Lyot type. A Lyot scrambler is
made of two multi order retarders having thickness ratio of 2 : 1 and with
fast axis of one aligned at 45 degrees to fast axis of the
other.
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