Micro lens array is an array composed of lens with aperture and embossed depth of micrometer. It not only has the basic functions of traditional lens such as focusing and imaging, but also has the characteristics of small unit size and high integration, which enables it to complete the functions that traditional optical elements cannot complete and can constitute many new optical systems.
Micro lens arrays can be divided into refraction micro lens arrays and diffraction micro lens arrays. Diffractive micro lens arrays modulate and transform light waves by using the three-dimensional relief structure of wavelength level on the surface, which is light, thin and flexible in design. As a functional component, it can be widely used in many kinds of systems, such as wave front sensing, optical shaping and so on.