The wavelength range of infrared light:
The three bands that can pass through the atmosphere are divided into:
Near-infrared band 1 to 3 microns
Mid-infrared band 3 to 5 microns
Far-infrared band 8 to 14 microns
Based on the infrared spectrum, it is divided into:
Near-infrared band 1 to 3 microns
Mid-infrared band 3 to 40 microns
Far-infrared band 40 to 1,000 microns
Medical field is often divided into:
Near-infrared region 0.76 to 3 microns
Mid-infrared region 3 to 30 microns
Far-infrared region 30 to 1,000 microns
Medical infrared can be divided into two categories: near-infrared and far infrared. Near infrared or short-wave infrared, wavelength 0.76 ~ 1.5 microns, penetrate into the human body tissue is deeper, about 5 ~ 10 mm; far infrared or long-wave infrared, wavelength 1.5 ~ 400 microns, more than the surface layer of the skin to be absorbed, penetrate into the tissue depth of less than 2 mm. (But in practice, usually more than 2.5 microwaves of infrared commonly referred to as far infrared.)