Infrared

Infrared (IR) emission is electromagnetic emission of a wavelength longer than that of noticeable light, but shorter than that of radio waves. The name means "below red" (from the Latin infra, "below"), red being the color of detectable light of longest wavelength. Infrared radiation spans three instructions of magnitude and has wavelengthsbetween about 750 nm and 1 mm.

These divisions are suitable by the different human response to thisradiation: near infrared is the area closest in wavelength to theradiation detectable by the human eye, mid and far infrared aregradually further from the visible regime. Other definitions followdifferent physical mechanisms (emission peaks, vs. bands, waterabsorption) and the newest follow technical reasons (The commonsilicon detectors are sensitive to about 1,050 nm, while Inga Assensitivity starts around 950 nm and ends between 1,700 and 2,600 nm,depending on the specific configuration). Unfortunately theinternational standards for these specifications are not currentlyobtainable.

The boundary between visible and infrared light is not preciselydefined. The human eye is markedly less responsive to light above 700nm wavelength, so longer frequencies make irrelevant contributions toscenes illuminated by common light sources. But particularly stronglight (e.g., from lasers, or from bright daylight with the visiblelight removed by colored gels) can be detected up to approximately780 nm, and will be apparent as red light. The onset of infrared isdefined (according to different standards) at different valuestypically between 700 nm and 780 nm.