For laser beam propagation from Air to an NLO crystal (with refractive index n). Brewster's angle is defined as θ_B=arctan(n). At Brewster's angle, the surface reflectance is zero for the light with polarization inside the plane defined by the direction of light propagation and the normal to the surface.

In order to have a low surface reflection, Brewster's angle cut (B-cut) NLO crystals are used. Scitec Instruments can supply the standard B-cut crystals according to Figures shown below. We can also supply crystals cut to the customers own drawings, for further details please contact us.