Fresnel Rhombs

Fresnel rhombs alter the polarization of radiation using the phase shift between orthogonally polarized components at total internal reflection, operating over a wide wavelength range. A λ/4 rhomb converts linear into circular polarization like a quarter-wave plate, while a λ/2 rhomb, made of two optically contacted λ/4 rhombs, rotates the polarization plane without changing beam direction. Rhombs are made of BK7 or UV fused silica, AR coated, unmounted or in rotatable holders.