Reflector

A reflector reflects light or an electromagnetic wave in a particular preferred direction. Reflectors are therefore a passive aid that does not actively produce light. Instead, they direct it back in the direction from which it came. In principle, there are different types of reflectors, such as planar mirrors of different shapes, but there are also three-dimensional reflector structures, such as retro-reflectors for light (retro-reflection). More generally, reflectors for electromagnetic waves are also found in radar applications as well as in deflector plates for ultrasonic waves.