A corner cube retroreflector, also known as a CCR or trihedral prism manufactured from fine BK7 optical glass. It is an optical structure that consists of three adjacent, mutually-orthogonal plane-reflecting surfaces which form the corner of the cube. The corner cube reflects an incident ray at a specific angle, independent of the prism and beam orientations.
Typical corner cube designs reflect the incident light at 180 degrees. Some applications require the reflected ray to return at a different angle. A number of coating options are available for corner cube retroreflectors. The front face may have an anti-reflective (AR) coating applied, and the three reflecting faces may have a metallic or dielectric coating, or may remain uncoated.
Corner cubes are used in a wide variety of applications such as spectroscopy, battlefield technology laser resonator cavities, land surveying, ground-based range finding, satellite communications, and space vehicle docking.