Fresnel Rhomb Retarders like broadband waveplates providing uniform λ/4 or λ/2 retardance over a wider range of wavelengths than possible with birefringent waveplates. They can replace retardation plates for broadband, multi-line or tunable laser sources.
The rhomb is designed so that a 45° phase shift occurs at each internal reflection creating a total retardance of λ/4. Because the phase shift is a function of the slowly varying rhomb dispersion, the retardance change with wavelength is much lower than other types of retarders. The half wave retarder combines two quarter wave rhombs.
Features：
•Quarter-Wave or Half-Wave Retardance
•Broader Wavelength Range than Waveplates
•Cemented Prisms