Definition: infrared

An invisible band of radiation at the lower end of the visible light spectrum. With wavelengths from 750nm to 1mm, infrared starts at the end of the microwave spectrum and ends at the beginning of visible light. Infrared transmission typically requires an unobstructed line of sight between transmitter and receiver.

Widely used in most audio and video remote controls, infrared transmission is also used for wireless connections between computer devices (see IrDA) and a variety of detectors (see IR detector).

Infrared Can Be Anything Below Red
Infrared means "below red," and red frequencies are at the bottom of visible light. Therefore, infrared may refer to any type of invisible electromagnetic radiation below visible light, including AM, FM and TV. See infrared imaging, infrared wavelengths, IR remote control and IRED.

Infrared in the Spectrum

The infrared band comes after the microwave range and ends at visible light.