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 Âµm and 50 Âµm including 3 major sub spectral ranges corresponding to the atmosphere transmission windows:
- 1 Âµm to 3 Âµm or Short Wave Infrared (SWIR) or band I
- 3 Âµm to 5 Âµm or Middle Wave Infrared (MWIR) or band II
- 8 Âµm to 14 Âµm or Long Wave Infrared (LWIR) or band III.