What is Infrared:
Those electromagnetic signals whose frequencies are higher than 300 GHz are not referred to as radio waves. Special names are given to the various bands in the spectrum beyond that point. The infrared region is sandwiched between the highest radio frequencies and the visible portion of the electromagnetic spectrum. Infrared occupies the range between approximately 0.01 millimeter (mm) and 700 nanometers (nm) or 0.7 to 10 microns (um). Infrared frequencies are often given in microns, where a microns one millionth of a meter (m), or in nanometers or one billionth of a meter.
Infrared is divided into two areas
- Long Infrared (0.01 nm to 1000 nm)
- Short Infrared (1000 to 700 nm)
How Infrared is produces:
Infrared refers to radiation generally associated with heat. Anything that produces heat generates infrared signals. Infrared is produced by light bulbs, our bodies, and any physical equipment that generates heat. Infrared signals can also be generated by special types of light emitting diodes.
Applications of Infrared Signals:
Infrared signals are used for various special kinds of communications. For example, infrared is used in astronomy to detect stars and other physical bodies i the heavens. Infrared is also used for guidance in weapons systems where the heat radiated from airplanes or missiles can be picked up by infrared detectors and used to guide missiles toward these targets. Infrared is also used in most new TV remote control units where special coded signals are transmitted by infrared to the TV receiver for the purpose of changing channels, setting the volume, and other functions.
Infrared signals also have many of the same properties as light. Optical devices such as lenses and mirrors are often used to process and manipulate infrared signals.