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Retarders are made of bi-refringent material. The phase shift is dependent on the orientation of the material producing a modified polarized state. In order to create a circular polarization the phase must be ¼ wavelength. WP retarders are durable high transmission polymer sheets which create a phase difference of ¼ wavelength of 140nm at 560nm. More

WP140HE
WP140 is a high transparent chromatic ¼ wavelength retarder based on a single layer polymer sheet. WP140 utilizes the latest technology to produce an achromatic retarder by using a modified polycarbonate sheet which has outstanding transparency and durability.
Retardation 142nm = a ¼ wave retardation.

CP42
 
Datasheet WP140 HE

WP280HE

Two films of WP140HE are laminated together in a paraxial fashion as a half-wave-length polarizer to create a WP280HE retarder.
Retardation 280nm = a ½ wave retardation

WP 560

A multiple combination of WP140HE films laminated together creates a retardation value of 560nm. This special combination is a full-wave-length polarizer which is used for a plate in microscopes or for analysis in a Polariscope.