Polarisation component esp. for polarisation microscope - has glass cover plates eliminating effects of adhesive layers

摘要

A polarisation component, for producing or modifying linearly, circularly or elliptically polarised light, consists of pref. two plane-parallel wedge-shaped or spherical transparent cover plates, each bonded by a transparent solid or liq. layer to the foil-, plate- or wedge-shaped active polarising element. At least one of the cover plates (1,5) consists of either (a) a material with a thermal expansion coefficient of between -0.5 and +0.5 x 10 power (-6) m/m.K; (b) a material with an optical strain constant (B) of between -0.7 and +0.7 TPa-1. Pref. material (a) is a SiO2 or TiO2 glass and material (b) is a lead phosphate glass. USE/ADVANTAGE - The component is esp. useful for polarisation microscopes requiring high extinction of the polarisation field. The adhesive layer does not cause double refraction in the component.