In 1800, Germany scientist William Herschel found what is incapable by eye and out of sun red light electric wave and similar light from heat effect of  prismatic spectrosynthesis. Thus, it is called Infrared ray.

Wavelength of infrared is between 0.78um and 1000um. Partial short wavelength links visible light. And long wavelength lap microwave. (as pictures) But , according to effect, 4um electromagnetic wave and upward are with good effect. Commonly, we separate near, meddle and far infrared ray from different wavelength. Some people called over far infrared ray from 25um to 100um.

Far Infrared Ray is partial sunlight. Usually, we can see red, orange, yellow, green, blue, indigo and purple light waves and their wavelength are 0.4-0.75 called visible light. Therefore, over that wavelength is called invisible light. Infrared separates near, meddle and far infrared. According to AMA report on August 7th, 1981, human is able to radiate energy and the highest wavelength is 9.4um so 4-14um wavelength energy is good for human. Thus, we called growing light. The growing light is main factor for creature grows. Cells compose of several creature and main molecules are water and macromolecular compounds. Growing light is able to reduce to active water molecules. The molecules or atom compose of  frequency and cells. Their active frequency is the same so the energy is able to absorb by cells to cause resonance. When the resonance of molecules raises to active system of cells, it is able to improve blood circulation, to provide nutrition and enzyme speedily and to increase metabolism. Far Infrared Ray is with against bad smell, dry, antiseptic functions.