Crystal Polarisers

Knight Optical supplies a range of custom crystal polarisers made to your custom specification.

Custom glan-Taylor polarizers: We supply custom Glan-Taylor polarizers for use in the UV, visual, and NIR wavebands (<0.2 to >2.3µm). Custom glan-taylor polariser consists of two prisms that are made, for example, from crystal quartz or calcite that have hypotenuses that are cemented together to form a polarizing prism. This prism has two output ports, one that is designed to provide an undeviated path from the input beam. This beam contains the extraordinary ray from the birefringent material. The ordinary ray is deviated to exit from a port that is situated atop the prism. The deviation angle is typically about 68° to the incident beam, where the beam is deviated backwards relative to the extraordinary ray. These custom glan-taylor polarisers are available in sizes up to about 20mm square that fit into the assembly kits available on request. The extinction ratio is typically about 100,000:1 for the glan-taylor design.

Custom Wollaston polarizers: Custom wollaston polarisers are available for use in the UV, visual, and NIR wavebands (<0.2 to >2.3µm). Custom wollaston polariser consists of two 90° birefringent prisms that are made, for example, from quartz or calcite that have hypotenuses that are cemented together with the optical axes perpendicular to each other, and thus forms a polarizing prism. This prism has one output port, with the ordinary and extraordinary rays exiting from the port with a deviation of about 3° to 22° that is dependent upon the optical crystal, quartz or calcite for example. The random polarization of the input beam is turned into two output beams that have equal intensity, orthogonal polarizations, and a symmetric angular divergence. The extinction ratio for quartz and calcite is greater than 20,000:1, whilst other materials, such as high temperature alpha phase barium borate (a-BBO) and yttrium ortho-vanadate (YVO₄) have extinction ratios of greater than 200,000:1. A cemented type, the wollaston polarising beamsplitter deviates the two polarisation components of a beam at angles ±10 degrees from the input direction, with a small chromatic dispersion. We supply custom un-mounted wollaston polarisers and mounted versions in flanged clevis mounted type.

Custom Glan-Thompson polarizers: Knight Optical supplies custom glan-thompson polarisers for use in the UV, visual, and NIR wavebands (<0.2 to >2.3µm). Custom glan-thompson polarizer consists of two 90° birefringent prisms that are made, for example, from calcite that have hypotenuses that are cemented together with the optical axes perpendicular to the plane of reflection, and thus forms a polarizing prism. This prism has two output ports, with the ordinary being reflected out of the prism and the extraordinary ray exiting undeviated. The random polarization of the input beam is turned into two output beams that have nearly equal intensity, orthogonal polarizations. The glan-thompson polarizer is used in the mode where the ordinary ray (the reflected one) is absorbed at a beam stop and thus only the extraordinary ray is propagated. The extinction ratio for calcite is greater than 20,000:1. Custom glan-thompson polarisers are available in sizes up to about 20mm square that fit into assembly kits available on request.

Custom Rochon polarizers: We supply custom rochon polarisers for use in the UV, visual, and NIR wavebands (<0.2 to >2.3µm). The rochon polarizer consists of two 90° birefringent prisms that are made, for example, from calcite that have hypotenuses that are cemented together with the optical axes are parallel and perpendicular to the plane of the input and output window, and thus forms a polarizing prism. This prism has one output port, with the ordinary being transmitted undeviated through the prism and the extraordinary ray exiting deviated from the extraordinary ray. The random polarization of the input beam is turned into two output beams that have nearly equal intensity, orthogonal polarizations. The extinction ratio for calcite and quartz is greater than 20,000:1 and for a-BBO and YVO₄ the ratio is better than 200,000:1. These custom rochon polarisers are available in sizes up to about 20mm square that fit into assembly kits available on request.

Knight Optical supply high quality custom crystal polarisers made to our designs or supplied to your 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 crystal polarisers and service can improve your instrumentation and supply chain experience.