Near infrared band 1 ~ 3 microns
Mid-infrared band 3 ~ 5 microns
Far infrared band 8 ~ 14 micron
Someone according to the infrared spectrum is divided into:
Near infrared band 1 ~ 3 microns
Mid-infrared band 3 ~ 40 microns
Far infrared band 40 ~ 1000 micron
The medical field is usually divided like this:
Near infrared region 0.76 ~ 3 microns
The mid-infrared region is 3 ~ 30 microns.
Far infrared region 30 ~ 1000 micron
Medical infrared rays can be divided into near infrared rays and far infrared rays. Near-infrared or short-wave infrared, with wavelength of 0.76 ~ 1.5 micron, penetrating into human tissues, about 5 ~10 mm; Far infrared rays or long-wave infrared rays, the wavelength of which is 1.5 ~ 400 microns, are mostly absorbed by superficial skin, and the depth of penetration into tissues is less than 2mm. (But in practical application, infrared rays above 2.5 microwaves are generally called far infrared rays. )