Manufacturers and Suppliers of Electro-Optic Components

Rochon & Wollaston Polarisers

The Wollaston and Rochon polarizers are both beam splitting type devices which rely upon the large birefringence of calcite to cause a difference in the refraction angle at the interface between two differently orientated prisms. In both the Wollaston and the Rochon polarizer the prisms are usually cemented at the interface so the optical power handling is low as a result.

WOLLASTON TYPE

Wollaston prism polarizing beam splitters consist of two equal angle calcite prisms optically coupled with optic axis orthogonally crossed to the direction of propogation. The beam separation of about 20░ is then approximately balanced about the input beam axis. The transmission range for cemented prisms of 0.32 to 2.5Ám to 18░ at 2.5Ám.

ROCHON TYPE

In the Rochon polarizer one polarization state is transmitted undeviated through the prism while the orthogonal component is deviated approximately 10░. The straight through component is clearly chromatic while the deviated beam varies from 11░ at 0.32Ám to 8.5░ at 2.5Ám.

Diagram of Wollaston polariser Diagram of Rochon polariser
Wollaston Type BSW Rochon Type BSR

Specifications

Type Aperture
(mm)
Deviation
(deg)
Mount
Dia (mm)
Mount
Length (mm)
BSW 10 20░ 25 11
BSW 12 20░ 25 13
BSW 15 20░ 30 16
BSW 20 20░ 40 20
BSR 10 10░ 25 11
BSR 12 10░ 25 13
BSR 15 10░ 30 16
BSR 20 10░ 40 20

Both varieties can be made from optically contacted quartz. The beam deviation is then reduced to only 1░ and 0.5░ respectively because of the much lower birefringence of quartz compared to calcite. However, the spectral range is increased to 0.2 - 2.0Ám.




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