Beam splitter
From The Glossary of Digital Photography
Splits the incoming light into several equal portions in some digital cameras. Each portion of light is then sent to a different set of image sensors, usually one for each primary color (red, green, and blue). The three separate images are then combined to make a full-color image. This technique is usually found only in expensive cameras. The beam splitter often consists of prisms or half-silvered mirrors.
