The Fresnel lens is based on the principle of light diffraction and interference. It is a flat-shaped lens composed of a group of concentric rings after periodization of traditional geometric lenses. The Fresnel lens is light and thin due to the elimination of the geometric redundancy of the geometric lens. Fresnel lens originally used for the lighthouse was first designed by the French physicist Fresnel, hence the name. The original Fresnel lens was made of glass while modern Fresnel lens is usually made of plastic injection molding to reduce cost and weight. Due to the thin and light characteristics of Fresnel lens, it is widely used in projectors, AR / VR, infrared sensing, solar photovoltaic and other fields that have tight requirements on volume and weight.