What are infrared signals?

What is Infrared radiation?

Infrared radiation, sometimes called infrared light, is electromagnetic radiation with wavelengths longer than those of visible light. It is therefore generally invisible to the human eye, although IR at wavelengths up to 1050 nanometers from specially pulsed lasers can be seen by humans under certain conditions.Wikipedia

What are infrared signals?

Remote controls such as those used for your TV, DVD/Blu-ray or Cable box use infrared transmitters and receivers. The transmitter is basically nothing more than a flashlight that emits a light beam at a frequency that is lower than the human eye can detect.

The remote control sends out a specially timed sequence of pulses to transmit data to your TV or other devices. Each consumer electronics device manufacturer has its own set of protocols for these signals so that the signals intended for your TV, for example, do not interfere with those intended for your Blu-ray or cable box. Even within a single manufacturer, there are special codes that make sure you only control the device you want to control.

Infrared Transmitters

An infrared transmitter is a device that emits a beam of light in the infrared range, which is just slightly out of range of normal human vision and encompasses a wavelength of light longer than visible red light

Infrared Transmitters

Infrared Receivers

An infrared receiver is a communications device that can respond to emissions very close and below the frequency of visible light. Typically this is that about 38 kHz however some protocols use frequencies ranging from 36 kHz to 57 kHz. Modulating the signal ensures that other sources of infrared emission such as sunlight, light bulbs, or just the normal heat coming off of objects are not interpreted as a part of the signal. 

Infrared Receivers


  • Night vision
  • Thermal imaging
  • Infrared heating
  • Communications using Infrared
  • Infrared Spectroscopy


Infrared light is easily absorbed by anything in its path and disperses quickly. While this limits its use for long-range transmissions, it makes it ideal for short-range sensors such as in faucet controls in public restrooms and hand air dryers, where the devices turn on when hands are placed in close proximity to the path of the light beam and otherwise remain off to conserve power and water. 

Hazards of Infrared radiation:

  • Strong infrared radiation can cause blindness to the eye by damaging the retina or cornea depending on the intensity of radiation and hence Infrared proof goggles need to be worn while working with them as one will not be aware of these radiations as they are invisible.
  • When using infrared radiation for therapy where muscle pain and other pains are treated, care has to be taken to regulate the intensity of the radiation, otherwise, it can cause severe burns.
  • Elderly people can be prone to low blood pressure if exposed to infrared radiation.
  • If exposed to infrared radiation for a long time, the body can lose fluid or water and this can result in dehydration.

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