Low-loss deflection prism for a laser beam with Brewster angle

A low-loss deflection prism for a laser beam is proposed, and its various characteristics such as beam quality, transmittance, deflection angle, and polarization state are presented. The prism having a trapezoidal form is made from BK7 glass and is designed for a He-Ne laser beam. When a p-polarized beam is incident on the slant surface of the prism at the Brewster angle, the totally reflected and transmitted beam is deflected by 90 degrees, and the measured transmittance is nearly 98%. The theoretical transmittances of the proposed prism are compared with those of a Pellin-Broca prism.