Slab lens for realizing plane wave focusing by adopting metastructure surface

Abstract

Provided is a slab lens for realizing plane wave focusing by adopting metastructure surface. The slab lens for realizing plane wave perfect focusing by adopting the metastructure surface is characterized by carrying out periodic arrangement in the radial direction of the circle of the plane on eight V-shaped focusing structures, wherein each V-shaped focusing structure is arranged uniformly on the circular ring, the phases of the eight V-shaped focusing structures periodically arranged in the radial direction of the circle from the inside out are 0, pi / 4, pi / 2, 3pi / 4, pi, 5pi / 4, 3pi / 2 and 7pi / 4 respectively, and the linear interval is pi / 4; calculating the arrangement mode of the V-shaped structures in the radial direction according to phase distribution of perfect focusing; then, obtaining the number n=L / a of the structures needing etching on the circular ring through determining the corresponding position r of each focusing structure; and designing different microstructure groups and obtaining different focal-length slab lenses. According to the slab lens, holes need to be etched only in a 50 nm silver film, so that the thickness of the slab lens is very thin, and the slab lens is hopeful to be applied to the optical integration field.

Description

technical field [0001] The invention belongs to the field of optical imaging and relates to a novel metamaterial flat lens applied in integrated optics. Background technique [0002] Traditional optical lenses are generally made of optical glass, and are completed through three major processes of rough grinding, fine grinding and polishing. At present, the more common lenses with more mature production technology are generally spherical mirrors, but due to their own spherical aberration, they cannot directly obtain good focusing and imaging effects, so spherical aberration correction systems are often introduced at the back end. Secondly, the thickness of the traditional optical lens is far greater than the wavelength of the light wave. With the increase of the lens diameter, the difficulty of processing and forming the traditional optical material increases exponentially, and it is difficult to meet the design requirements of the optical parameters, and the volume and weigh...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to design a flat lens with a metasurface, especially to achieve almost perfect focus imaging on a plane wave with a wavelength of 1550nm, and to solve the problems of difficult processing and poor image quality of traditional lenses in the background technology

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