Excellent quality Bbo Crystal - Fresnel Rhomb Retarders – Dien

 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.

•Quarter-Wave or Half-Wave Retardance

•Broader Wavelength Range than Waveplates

•Cemented Prisms