Achromatic Waveplates
Achromatic waveplates are similar to zero-order except that the two plates are made of different materials, such as crystal quartz and magnesium fluoride. Since the dispersion of birefringence can be different for two materials, it is possible to specify the retardation value at a wavelength range. Hence, the retardation of the resulting waveplate can be made to low sensitivity to wavelength change.
Base on the contact methods of two plates, achromatic waveplates are classified into two types: air-spaced and cemented.
Capability:
Attribute | Commercial | High Precision |
Substrate Material | Crystal Quartz and MgF2 | Crystal Quartz and MgF2 |
Dimension Tolerance | +0，-0.2mm | 土0.05mm |
Wavefront Distortion | λ /4@632.8nm | λ /8@632.8nm |
Retardation Tolerance | λ /50@700m~ 100m(N(R)) | λ /10000m1000m(NIR) |
Wavelength Range | 400-2100nm | 400-2100nm |
Parallelism (Single Plate) | 3 arc seconds | 1 arc seconds |
Surface Quality | 40-20 | 10-5 |
Standard Wavelength | VIS:465nm-610nm NIR:700nm-1000nm IR:1200nm-1650nm | VIS:465nm-610nm NIR:700nm~1000nm IR:1200nm~1650nm |
