What are the wavelength boundaries of infrared radiation?
The infrared radiation is the electromagnetic radiation where wavelengths are between 700 nanometres and 1 millimetre. Thus, it is located between the red limit of visible spectrum and the shortest microwaves.
However, taking into account the major applications of thermal sensors, the main considered spectral range is between 1 µm and 50 µm including 3 major sub spectral ranges corresponding to the atmosphere transmission windows:
- 1 µm to 3 µm or Short Wave Infrared (SWIR) or band I
- 3 µm to 5 µm or Middle Wave Infrared (MWIR) or band II
- 8 µm to 14 µm or Long Wave Infrared (LWIR) or band III.