Fresnel Rhomb Retarder
Fresnel prism rhomb is advantageous than reflective phase retarder and waveplate that use birefringence material. The retardation depends on the index of refraction of material and geometry but not the design wavelength. The desired phase shift can be constructed by shining light in the 8-12µm region at a selected incident angle, allowing it to make the required number of internal reflections by using the principle of total internal reflection. The rhomb improves the quality of laser cutting in laser processing applications.