Rotator

Variable Rotator

Variable Rotator

This useful instrument introduces a variable rotation between 0° and 90° to an input plane polarized beam.The rotation angle is controlled by a manually driven precision micrometer. Calibration scales are supplied to enable any desired rotation to be set for a given wavelength of operation.

Theory                      
The VR100 Variable Rotator is constructed from two leftrotating opposed crystal quartz wedges with a compensating right-rotating crystal block in optical contact with the smaller wedge. Both wedges and the compensating block are cut with the optic axis parallel to the beam propagation direction. In operation, the large wedge is translated across the smaller, thus presenting a variable amount of left rotation to an optical beam passing through the Instrument. The compensating block introduces the exact opposite right rotation when the instrument is set at the zero position.
The input beam propagates through both wedges, and suffers a rotation of its plane of polarization proportional to the difference in thickness between the two combined wedges and the compensating.

Model VR100
This rotator,using natural optically active crystal quartz elements,is designed for use over the wavelength range 230nm-1100nm,covering the mostpopular laser wavelengths from Nd:YAG 4th harmonic @ 266nm to the fundamental @ 1064nm. The variable rotator is factory preset for zero rotation at the micrometer zero position, and we supply a calibration curve for the calculation of rotation vs micrometer setting at any wavelength within 230nm-1100nm.
Note that this variable rotator is completely linear:i.e.at a given wavelength, rotation scales in direct proportion to the micrometer reading.

Specifications:
Aperture (mm): ---------------------------------------------------------- 10
Spectral Range (nm): -------------------------------------------------- 230-1100
Rotation range:------------------------------------------------------- 0°-90°
Calibration accuracy:--------------------------------------------------- +/-1°

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