Fabricating fresnel mirrors imaged in visible light region by ultra precision manufacturing technology

Abstract

Fresnel mirror can greatly improve the compactness of imaging system, which has many advantages such as light, thin, and easy to integrate. Due to the limitations of the shape precision and the surface roughness by available fabrication technology, most Fresnel mirrors can only be used for illuminating and focusing areas. This paper presents a Fresnel mirrors ultra precision forming method, which can turn the Fresnel mirrors with an excellent imaging performance in visible light region. The surface roughness of the Fresnel mirror can be achieved as small as 1 nm, and the surface accuracy can be up to 0.23 lambda @ 632.8 nm after removing the spherical aberration, which make this kind of Fresnel mirror extremely promising for applications in ultrathin and light optical imaging system.