Achromatic Waveplates

Dayoptics has special designed achromatic waveplates by using two pieces of plates. It is similar to Zero-order waveplate except that the two plates are made from different materials, such as crystal quartz and magnesium fluoride. Since the dispersion of the birefringence can be different for the two materials, it is possible to specify the retardation values at a wavelength range. From the curve, you can see that the bandwidth of such achromatic waveplate is very wide, while the achromatic waveplates remain a nearly constant retardance over a range of wavelength.

Achromatic Waveplate Optical Cemented