Lyot Depolarisers

Knight Optical supply custom Lyot depolarizers for use in the UV, visual, and NIR wavebands (<0.2 to >2.3µm). The Lyot depolarizer consists of two waveplates that are made, for example, from quartz, where one wave-plate has twice the thickness of the other. The first, L depth, wave-plate has the optical axis of the crystal in a vertical direction, for example. The second wave-plate, 2L depth, has the optical axis rotated at 45° to the first. That is the L wave-plate has the optical axis pointing up and parallel to the input beam of linear polarization, and the 2L wave-plate has the optical axis rotated about the propagation axis by 45°. These wave-plates are cemented together. Thus a random polarization beam exits the 2L wave-plate. Anti-reflection coatings are applied to the two windows. The minimum wavelength bandwidth, which is a measure of how random the beam becomes following its passage through the Lyot depolarizer, is about 50nm. This 50nm represents an 85% depolarization. The bandwidth needs to be greater than 100nm for complete depolarization.

These custom Lyot depolarisers are available in sizes up to about 20mm square that fit into assembly kits available on request.

Knight Optical supply high quality custom Lyot depolarizers and manufactured to your complete custom specification. Every component is individually tested by our highly skilled technicians in our state of art metrology lab to ensure all components meet our high quality standards.

Contact our multilingual technical sales team and discover how Knight Optical’s high quality custom Lyot depolarizers and service can improve your instrumentation and supply chain experience.