Infrared (IR) refers to the region of the electromagnetic spectrum with wavelengths longer than those of visible light, but shorter than those of microwaves. The infrared spectrum spans wavelengths roughly between 700 nanometers (nm) and 1 millimeter (mm). It is divided into three main subcategories:
Near-infrared (NIR): Wavelengths from approximately 700 nm to 1.4 micrometers (µm). Near-infrared light is often used in telecommunications, as well as in various imaging and sensing applications.
Mid-infrared (MIR): Wavelengths from about 1.4 µm to 3 µm. Mid-infrared radiation is commonly employed in spectroscopy for analyzing molecular vibrations, and it is also used in various sensing applications.
Far-infrared (FIR): Wavelengths from approximately 3 µm to 1 mm. Far-infrared radiation is often used in thermal imaging and has applications in astronomy for studying cool objects in space.
Infrared radiation is emitted by all objects with a temperature above absolute zero (0 Kelvin or -273.15 degrees Celsius). Infrared technology is widely used in various fields, including night vision devices, thermal imaging cameras, communication systems, remote sensing, and industrial processes, among others.