Standa manufactures Fresnel Rhombs and mounts for them.
14FR is a combination of a rhomb with a mount (see drawings).
Fresnel Rhombs are made of BK7 crown glass or UV grade fused
silica. A Single Fresnel Rhomb produces a phase shift of 90°
(λ/4) due to total internal reflections at two surfaces. A Double
Fresnel Rhomb produces a phase shift of 180° (λ/2) between the
components of light polarised perpendicular and parallel to the
plane of incidence. It consists of two optically contacted (or air
spaced) single Fresnel λ/4 Rhombs. The retardation varies only
slightly over a relatively wide range of wavelengths. Fresnel
Rhombs mounts are cylindrical in shape. The end faces of a
Fresnel retarder are adjusted orthogonally to the axis of rotation.
The clear aperture of the mount is 10 mm.
There are several ways to mount the 14FR Fresnel rhomb retarder:
- on any adjustable unit (e.g. a stage) by the M6 and M4 tapped holes;
- to our Polarizer Holder as 5PH50, 5PH51 or other compatible unit using the M27x1 thread.