Variable Optical Rotator

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The Variable Rotator is constructed from two left-rotating 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 block.The wedge angle is calculated such that full scale movement from zero introduces a 90° rotation at the longest design wavelength of 1100nm.

VR100 Variable Rotator

This rotator, using natural optically active crystal quartz elements, is designed for use over the wavelength range 230 - 1100nm, covering the most popular 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.

Custom Variable Rotators

As well as the standard 10mm aperture, this instrument can be supplied customised up to 20mm aperture, price on application.

Specifications