Retarder Applied Polymer (RAPtor) parts are manufactured using a proprietary high birefringent polymer. These retarders are true zero order with a typical film thickness less than 10 microns. The material can be added to customer provided windows and even mildly curved substrates to produce truly custom solutions.
These retarders were originally designed for use in astronomy but have applications wherever a true zero order waveplate would be used. Meadowlark Optics can apply these retarders to substrates from 10 mm to 100 mm diameter (and even larger on a custom basis).