cornerreflects

Cornerreflects, or corner reflectors, are devices that reflect light back toward the source. The most common form is the trihedral corner reflector, formed by three mutually perpendicular flat surfaces that meet at a single corner, effectively creating a cube-corner geometry.

How cornerreflects work: An incident light ray strikes one surface and reflects to the second, then to the third, and exits roughly along the opposite direction of the incoming ray. For a wide range of incident angles, the reflected light returns toward the source, a property known as retroreflection. The precise return direction depends on the geometry, material, and coatings; real-world performance is influenced by surface quality and absorption or scattering within the device.

Types and construction: The standard type is the trihedral corner reflector (cube-corner) with three perpendicular faces. Materials commonly used include glass, fused silica, and metal-coated surfaces. Variants exist, but the trihedral corner reflector remains the archetype for efficient retroreflection. In practice, CCRs may be solid prisms or assembled from reflective faces to form the characteristic three-face corner.

Applications: Cornerreflects are used wherever stable, wide-angle retroreflection is advantageous. Applications include laser ranging and alignment targets, survey references, and precision measurement setups. Space missions employ arrays of cube-corner retroreflectors for lunar and other satellite laser ranging, enabling accurate distance measurements by returning a laser pulse to its source. Retroreflective components based on similar principles also appear in road safety and signage systems, where predictable return of light improves visibility.