Infrared is a kind of electromagnetic wave, and its position in the spectrum is on the outside of red light, so it is called infrared (Infrared). Infrared wavelength range is relatively wide, according to the use of near-infrared, mid-infrared, far-infrared. Outside of the far infrared is the frequency band of radio.

1. Near infrared

Near-infrared wavelength range between 700nm and 1400nm. 700nm is close to the wavelength boundary of the red color of visible light, 1400nm is completely unobservable infrared-A zone begins. Near-infrared light can penetrate glass and can also be reflected. It can be perceived by the human eye, but its color is deeper red and is perceived as black. Near-infrared light can be used for night-vision equipment, fiber-optic communications, and so on. This band is the main range of infrared led.

2. mid-infrared 

The mid-infrared wavelength range is between 1400nm and 3000nm, also known as infrared-B and infrared-C range. This part of the infrared can not be observed with the naked eye, it is mainly in the form of thermal radiation to release energy. The mid-infrared can be used for temperature measurement and night vision.

3. Far infrared

Far infrared wavelengths are between 3000nm (3 microns) and 1mm, corresponding to the infrared-C and infrared-D ranges. This part of infrared radiation exists in the form of thermal radiation, which can be used for thermal imaging and industrial heating. The absorption of far infrared radiation varies from substance to substance, which can be used for substance identification.

At the current level of technology, infrared led wavelength range between 700-1600nm, Hongshuo photoelectric infrared led lamp beads cover this wavelength range, the application of more products have 700nm, 850nm, 940nm, 1050nm, 1200nm, 1300nm, 1450nm, longer wavelengths of its penetration is better, but because of the photoelectric conversion efficiency is too low, so the practicality is not high.

Different substances absorb infrared rays with different absorption characteristics, which can produce infrared absorption spectra and be used to analyze the composition of substances. This is the basis of infrared spectroscopy. In nature, infrared rays play an important role in heat transfer, plant photosynthesis and other processes.