What are you looking for in Stock?
Knight Optical supplies a complete range of polarisers for a range of applications. Our stock polarizers cover waveband (<0.2 to >2µm). We can also supply our polariser ranges as custom polariser options made to your complete custom specification.
Sheet polarisers: Sheet polarisers were previously made by Polaroid/3M and marketed under the brand name ‘Vikuti’ are now obsolete, however Knight Optical still hold substantial stocks in full sheet sizes. Some of the material grades are also being replaced by alternatives. Original Polaroid/3M ‘Vikuti’ sheet polarisers are offered in a wide range of types, our visible range HN32, HN38 and HN42, and special high performance types HN22, HN38S and HN42HE, and our UV and IR range of HNP’B replacement material which is very efficient at 290nm and original polaroid infrared HR material that works well at 800-2000nm. Our range of stock sheet polarisers are CAB laminated however acrylic and AR coated glass laminated sheet polarisers can be supplied on request.
Circular polarisers: HNCP37 circular polarisers are comprised of a linear polariser cemented to a quarter wave plate, therefore polarising the output light. If light passes through the polariser and is reflected back from a mirror, the light that now enters the linear polariser component is polarised at right angles to the direction it will be passed and therefore will be absorbed. However the un-polarised light from the reflecting side will pass with a 50% transmission. This can substantially reduce the impact of ambient light on data displays, LCD screens or meters. A matt non glare finish reduces the reflection from the HNCP37 polariser itself. Our stock ranges of HNCP37 are offered in both non-glare and standard clear finish. We stock left and right handed options in HNCP37 material. These are available as large sheets for custom sizes.
Crystal polarizers: Crystal polarisers make use of the bi-refringence of crystal structures. The two orthogonal polarizations, termed the ordinary and extraordinary polarization, are separated from the input random polarization by the different refractive index that results from the crystal state. The crystal polarizers make use of the crystal structure with several prisms, usually two or three, that are orientated differently and this results in the ordinary and extraordinary beams exiting the crystal at different angles. It is usual to have the extraordinary beam pass through the crystal with little deviation and the ordinary beam being angled away for the input axis. The prisms that are commonly used have prism arrangements producing a high, 100,000:1, extinction ratio, and consists of the following types: the Glan-Taylor, the Wollaston,, the Glan-Thompson, and the Rochon designs. The materials commonly used are quartz and calcite.
Cube polarizers: Our range of cube polarisers are made from prisms that form a cube, such as two 45° prisms. The hypotenuse of the prisms has a thin film coating that when the two prisms are cemented together the ordinary beam is reflected at 90° to the input beam, whilst the extraordinary beam passes through the cube beamsplitter undeviated. This cube polarizing beamsplitter has an extinction ratio of about 1,000:1, which are less than the crystal polarizers. However, as the cube polarizing beamsplitter uses, for example, BK7 or equivalent optical glass that is cheaper than the for example, calcite used in the crystal polarizers. These can be used in less rigorous experiments and product applications.
Lyot depolarizer: The Lyot depolarizer consists of quartz prisms that are cemented together with the optical axis of the first prism orientated vertically and the second prisms optical axis at 45° to the first prisms axis. The lengths of the prisms are constrained to a length ratio of 1:2, that is the first prism has a thickness of 1 unit and the second thickness is twice the thickness of the first prism.
Polariser assemblies: We have capabilities to supply laminated polarisers in a range of materials and options. These can be supplied unmounted or in a host of mounted options for seamless integration into your instrument application.
- Sheet polarisers
- Circular polarisers
- Crystal polariser
- Cube polariser - Polarising Beamsplitters
- Lyot depolarisers
- Polariser assembly