Corner cube retroreflectors

BK7 and UVFS corner cube retroreflectors are designed to deviate incident light by 180 degrees independently of an angle of incidence. These prisms have three mirror surfaces with angles at 90° to each other, juxtaposed to form the corner of a cube with the entrance face perpendicular to the cube’s diagonal.

All beams, regardless of incident direction, are reflected towards the original direction. Corner cube retroreflectors can have an entrance face coated with low-absorption IBS AR coatings.

Another application for corner cube retroreflectors was demonstrated in 1962 during the Lunar Laser Ranging experiment. Researchers succeeded in observing laser pulses reflected from a corner      cube retroreflector array left on the surface of the Moon by those involved in the Apollo 11 mission.