Pellin-Broca Prisms

In a Pellin-Broca prism, an ordinary dispersing prism is split in half along the bisector of the apex angle and joined by a right angle prism, so that wavelength-separated light is turned by 90° by total internal reflection with minimum deviation. They have extremely small loss for p-polarized beams and are used to separate laser harmonics. Prisms are made of BK7 or UV fused silica in several sizes, typically uncoated.