Other Birefringent Crystal Components
Polarization Rotators (Crystal Quartz Rotators, Z-Cut)
Waveplates can be used to rotate the direction of linear polarization by an angle which is determined by the angle between the polarization vector and the optical axis of the waveplate: The linear polarization is rotated by exactly twice this angle (more general: it is flipped at the optical axis). This also means that different directions of linear polarization will be rotated by different angles with any specific setting of the waveplate.
In contrast, Z-cut quartz rotators will rotate any direction of linear polarization by the same angle. This angle, however, is wavelength dependent.
Wavelength | 248 nm – 1064 nm |
Rotation Values | 45° and 90° @ design wavelength |
Rotation Tolerance | +/- ≤ 0.5° @ design wavelength |
Thickness | 1.3 – 16 mm |
Diameter | 10 mm - 30 mm (>30 mm on request) |
Parallelism | ≤ 0.5 arc sec. |
Surface Quality | 10-5 scratch-dig |
Damage Threshold, cw | 1 MW/cm² cw @ 1064 nm |
Depolarizers:
Types | Cornu, Lyot, Hanle |
Beam Displacers, Calcite Rhombs
Dimensions | 10 mm - 30 mm |
Other Birefringent Crystal Components | 250 nm – 2700 nm |
Compensator Plates & Wedges
Compensator plates and wedges made of quartz and mica are useful for determination of the character of birefringence and of optical path differences in polarized light.
Plate Compensators
The crystal plates are cemented between two glass flats (2 – 3.5 mm thick). They are used as compensators in polarizing devices like microscopes and optical stress analyzers. Flatness of glass flats is 1 lambda, parallelism ≤ 3 minutes. These plate compensators are true zero order retarders in the visual wavelength range. Retardation (in nanometers) is specified and measured at 546 nm but is highly insensitive to wavelength.
Mica Step Compensator – Fedorov type
For comparative measurement we recommend our Mica Step Compensators.
The standard types have 6 gradations from 10 - 50 nm or from 30 - 120 nm. The individual gradations are measured in a half-shade compensator and marked accordingly.
The compensator can be used with white light for comparative measurements in the workshop.
For example:
45 | 60 | 70 | 80 | 115 | 130 | nm |
In testing for strains it is possible in practice to use objects – such as bottles, vials, tubes – that have been accepted by both the manufacturer and purchaser as reference samples in terms of tolerances. With complex hollow glass types, reflections and glare can make testing more difficult and may result in incorrect findings. The test should therefore be carried out in a cuvette with immersion liquid.
AR-coatings and mounts available upon request.