Editing Infrared (section)

=== Communications ===

{{Further|Consumer IR}}

IR data transmission is also employed in short-range communication among computer peripherals and [[personal digital assistant]]s. These devices usually conform to standards published by [[IrDA]], the Infrared Data Association. Remote controls and IrDA devices use infrared [[light-emitting diode]]s (LEDs) to emit infrared radiation that may be concentrated by a [[lens]] into a beam that the user aims at the detector. The beam is [[On–off keying|modulated]], i.e. switched on and off, according to a code which the receiver interprets. Usually very near-IR is used (below 800&nbsp;nm) for practical reasons. This wavelength is efficiently detected by inexpensive [[silicon]] [[photodiode]]s, which the receiver uses to convert the detected radiation to an [[electric current]]. That electrical signal is passed through a [[high-pass filter]] which retains the rapid pulsations due to the IR transmitter but filters out slowly changing infrared radiation from ambient light. Infrared communications are useful for indoor use in areas of high population density. IR does not penetrate walls and so does not interfere with other devices in adjoining rooms. Infrared is the most common way for [[remote control]]s to command appliances.
Infrared remote control protocols like [[RC-5]], [[Sony Infrared Remote Control|SIRC]], are used to communicate with infrared.

[[Free-space optical communication]] using infrared [[laser]]s can be a relatively inexpensive way to install a communications link in an urban area operating at up to 4 gigabit/s, compared to the cost of burying fiber optic cable, except for the radiation damage. "Since the eye cannot detect IR, blinking or closing the eyes to help prevent or reduce damage may not happen."<ref>{{Cite web |title=Dangers of Overexposure to ultraviolet, infrared and high-energy visible light |url=http://www.ishn.com/articles/94815-dangers-of-overexposure-to-ultraviolet-infrared-and-high-energy-visible-light |date=2013-01-03 |archive-url=https://web.archive.org/web/20160816163547/http://www.ishn.com/articles/94815-dangers-of-overexposure-to-ultraviolet-infrared-and-high-energy-visible-light |archive-date=2016-08-16 |access-date=2017-04-26 |website=ishn.com – Industrial Safety & Health News}}</ref>

Infrared lasers are used to provide the light for [[optical fiber]] communications systems. Wavelengths around 1,330&nbsp;nm (least [[Dispersion (optics)|dispersion]]) or 1,550&nbsp;nm (best transmission) are the best choices for standard [[silica]] fibers.

IR data transmission of audio versions of printed signs is being researched as an aid for visually impaired people through the [[Remote infrared audible signage]] project.
Transmitting IR data from one device to another is sometimes referred to as [[beaming]].

IR is sometimes used for assistive audio as an alternative to an [[audio induction loop]].