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Foster Polarizers

The p-polarized ray passes undisplaced. The s-polarized ray is reflected and is transmitted through a hole in the wall of the enclosure. A modification involves mirror coating this top surface to reflect the s-polarized beam down at 90° to the transmitted beam. Only the transmitted ray has high polarization purity. Cemented: low power handling.

The Foster polarizer is made of two calcite prisms cemented together. The output beams separate at an angle of 45°.

Although both beams are available for use, only the undisplaced beam is of the exceptionally high polarization purity generally associated with crystal polarizers. The 45° reflected beam has a much lower degree of polarization.

As with all of our optics, we will gladly provide these items custom designed to your particular requirements. As an alternative, we offer a selection of standard Foster polarizers as specified below.

Standard products:

Foster Polarizers

Order No.L/AExtinction RatioAngular Field (°)CA phi a (mm)O.D. phi d (mm)L ± 0.1 (mm)
50.230.001112.4<5x10-5>15 8.050.833.0

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