A long-wave infrared broadband achromatic metasurface lens

Abstract

The invention discloses a long-wave infrared broadband achromatic metasurface lens, which belongs to the field of infrared imaging and micro-nano photonics. The metasurface lens units in the metasurface lens are periodically arranged in the form of a square lattice; the metasurface lens units It is composed of a dielectric substrate and a microstructure located in the center of the dielectric substrate, and the projection pattern of the microstructure on the dielectric substrate is a figure that is rotationally symmetrical about a 90° angle; the phase and phase dispersion introduced by the microstructure at different positions satisfy and The microstructure selection method at each position is as follows: according to the above two formulas, the theoretical parameter combination is obtained, and the phase of the unit where each microstructure is located and the corresponding phase dispersion are obtained through weighted first-order linear fitting, which is recorded as the actual parameter combination. Each parameter combination is drawn in the same scatter diagram, and the microstructure corresponding to the actual parameter combination closest to the theoretical parameter combination is selected. The invention can realize broadband achromatic aberration in the long-wave infrared band.

Description

technical field

[0001] The invention belongs to the fields of infrared imaging and micro-nano photonics, and more specifically relates to a long-wave infrared broadband achromatic metasurface lens. Background technique

[0002] In traditional infrared optical systems, refractive optical elements such as glass lenses are usually used to achieve imaging. This type of lens realizes the regulation of light through the refraction of the front and rear surfaces. Compared with the overall volume of the lens, the actual working area volume is low in space utilization, resulting in The problem of miniaturization and miniaturization of the optical system is solved. As an emerging sub-wavelength artificial material, metasurfaces can be arbitrarily adjusted to various optical properties such as the amplitude and phase of the incident light through the artificial design of the array unit, resulting in a series of novel physical properties, such as negative refraction. High-efficiency ma...

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