Infrared

Form of electromagnetic radiation

Infrared radiation (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those of red light (the longest waves in the visible spectrum), so IR is, per definition, invisible to the human eye. IR is generally (according to ISO, CIE) understood to include wavelengths from around 780 nm (380 THz) to 1 mm (300 GHz).

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