A corner cube, also known as a corner reflector or retroreflector prism, is a type of optical device used to reflect light or electromagnetic waves back towards their source with minimal deviation in direction. It consists of three mutually perpendicular reflective surfaces arranged in a triangular prism configuration, with each surface forming a 90-degree angle with the adjacent surfaces.
Key features and characteristics of corner cubes include:
Reflective surfaces: The three surfaces of a corner cube are typically coated with a highly reflective material, such as metal or dielectric coatings. These coatings ensure that incident light undergoes multiple reflections within the prism, resulting in the light being redirected back along its original path.
Total internal reflection: Corner cubes exploit the principle of total internal reflection to achieve their retroreflective properties. When light enters the corner cube, it undergoes multiple internal reflections off the three surfaces, ensuring that the outgoing light is reflected back towards the source with minimal deviation.
High angular Tolerance: Corner cubes have a wide angular acceptance range, allowing them to effectively reflect incident light over a broad range of angles. This property makes corner cubes suitable for applications where precise alignment or orientation is challenging.
Passive operation: Like retroreflectors, corner cubes operate passively and require no external power source or active components to function. This simplicity and reliability make them widely used in various optical systems and applications.
Applications: Corner cubes find applications in numerous fields, including surveying and geodesy (prism targets for total stations), astronomy (retroreflectors for laser ranging to satellites and lunar reflectors), optical communication (free-space optical links), lidar systems (for range finding and remote sensing), and optical instrumentation (alignment and calibration).