Optical rotator and rotation-angle-variable half-waveplate rotator
OwnerChun Yeinventor
Life of this patent
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Abstract
The device of the present invention for an optical rotator and a half-waveplate rotator comprises a retarder or polarization modulator interposed between two crossed or parallel quarter-wave plates, depending on being used as optical rotator or half-waveplate rotator, oriented such that the fast or slow axis of the retarder or modulator is at angle of 45.degree. relative to fast or slow axes of the quarter-wave plates. The rotation angle of the optical rotator and half-waveplate rotator is equal to one-half the retardance of the retarder or modulator and electrically adjustable when using a polarization modulator.
Claims9
In an optical system with a monochromatic or quasi-monochromatic illumination a rotator device comprising a retarder or polarization modulator and two quarter-wave plates, wherein said retarder or polarization modulator and said quarter-wave plates are oriented in cascade with said retarder or polarization modulator interposed between said quarter-wave plates.
A method for rotating a polarized light beam from a monochromatic or quasi-monochromatic illumination comprising the steps of:
- propagating and passing said polarized light beam sequentially through a first quarter-wave plate, a retarder or polarization modulator and a second quarter-wave plate;
- orientating said retarder or polarization modulator such that its fast or slow axis is at an angle of 45.degree. related to that of said first quarter-wave plate;
- and
- orienting said second quarter-wave plate such that the fast axis of second quarter-wave plate is perpendicular or parallel to that of said first quarter-wave plate if said polarized light beam is linearly polarized or perpendicular to that of said first quarter-wave plate if said polarized light is elliptically polarized.
Dependencies are inferred from the claim text.