Two multiorder crystalline retarders, one made of crystalline quartz and the other magnesium fluoride, are combined in a subtractive mode to give an effective zero-order waveplate.
Custom designs with larger achromatic ranges, or deeper UV wavelengths, are available on request.
They have higher power handling capability than our polymer achromats, and can withstand higher storage temperatures. Their field of view is narrow compared to polymer achromats. Typically, they cannot be expected to meet their retardance accuracy for rays whose incidence angles exceed 1.5 . If you must have the performance of a bi-crystalline achromat and a large field of view, call us. Click here to return to retarders page .