Quartz Retardation Plates and Rotators
For control of the state of polarization
Low Order Quartz Retardation Plates
These retardation plates use high optical damage threshold crystal quartz. They are orientated with the optic axis in the plane of the plate and light polarised at 45° to the quartz optic axis is resolved into two equal amplitude components that suffer a relative phase retardation due to their different propogating velocities. Most low order plates lie in a thickness range of 100-200µm (At 1.06µm a first order λ/2 plate is aproximately 182 µm thick). Low order plates are generally used because they are relatively temperature insensitive compared to high multiple order plates. They are also less sensitive to axial misalignment.
Retardation plates can be supplied mounted or unmounted with or without A.R. coatings.
Specifications
| Material | Crystal Quartz |
| Surface Quality | 20 - 10 |
| Diameter Tolerance | + 0.00mm - 0.1mm |
| Retardation Tolerance | λ/250 |
| Damage Threshold | > 1 GW/cm2(~1ns pulse length at 1064 nm) |
| Max cw Power | >200W/cm2 |
| Transmission Uncoated | 92% |
| Spectral Range | 220 - 2800 nm |
Standard Sizes
| Type | Clear Aperture | Mount Dia. |
|
QWP 10 |
10mm |
25mm |
| QWP 20 | 20mm | 25mm |
| QWP 25 | 25mm | 35mm |
| QWP 30 | 30mm | 40mm |
Low order Half and Quarter wave plates having the above dimensions are held in stock and can be supplied coated or uncoated. They are generally available from stock for most common laser wavelengths. All waveplates can be supplied mounted or unmounted. Other dimensions can also be supplied.
Dual Wavelength Plates
For a given plate thickness a low order waveplate will operate as a quarterwave, halfwave and full wave plate at different wavelengths. By selecting the thickness it is possible to achieve a dual order plate giving for example, halfwave retardation at 1064 nm and fullwave retardation at 532 nm. Because of the wide range of possibilities these plates are not held in stock, but we would be pleased to manufacture plates where possible to customer requirements.
Quartz Optical Rotators
When plane polarised light propogates along the optic axis of quartz, it is rotated clockwise or anticlockwise depending on whether it is right or left hand quartz. The rotation is dependent on the wavelength and the distance travelled, as shown below.
Quartz rotators can be supplied to give 90° rotation or any angle between 0-90°. They are ordered as standard components with the same aperture and mount dimensions as those shown for retardation plates but by using the suffix, QOR.