Optical Retroreflector Prism
Corner cube prism, AKA retroreflector, is an optical device that reflects light or other waves back to their source. Its three mutually perpendicular reflective surfaces intersect at a common point, form the corner of a cube. Light ray entering the prism is reflected off the three surfaces, ultimately back parallel to its original direction. This property makes it useful applications such as rangefinders, surveying instruments where precise alignment of the return beam is necessary.
