Planar optical element and design method thereof

Abstract

The invention relates to a planar optical element and a design method thereof. The design method of the planar optical element comprises the following steps of: designing a group of antennas, setting a wavelength of incident circularly polarized lights, constant structure parameters of the antennas, position coordinates of the antennas and a target parameter of a photo-induced result, and setting changeable structure parameters of the antennas; regarding the antennas as an array element and designing a two-dimensional antenna micro-array; composing the planar optical element by using a substrate and a metallic film with the two-dimensional antenna micro-array structure. According to the method of the invention, the phase of the circularly polarized lights in an opposite chiral state excited during the incidence of the circularly polarized lights is modulated through modulation of the structure parameters of the antenna array element, the circularly polarized lights in different chiral states are focused to different positions so as to realize the purpose of separating left circularly polarized lights from right circularly polarized lights, the design method of the planar optical element is a reliable design method. The planar optical element designed by the method disclosed by the invention realizes an ideal polarization separation effect and fills a vacancy of the conventional optical elements in the circularly polarized light separation aspect.

Description

technical field [0001] The invention relates to the field of optics, in particular to a planar optical element and a design method thereof. Background technique [0002] Circularly polarized light is a light wave in which the electric vector rotates at a constant speed at an angular velocity ω in the wavefront and the instantaneous value is constant. According to the theory of vertical vibration synthesis, linearly polarized light with equal amplitude, perpendicular polarization and phase difference of ±π / 2 can be synthesized into circularly polarized light, which can be divided into left-handed and right-handed circularly polarized light according to the positive or negative phase difference. [0003] There are two main types of existing circularly polarized light separation technologies. One is to use the traditional quarter-wave plate and polarizer. Linearly polarized light, and then use a polarizer to detect the generated linearly polarized light, and then realize the d...

AI Technical Summary

Problems solved by technology

[0004] Although the method of using the traditional quarter-wave plate and polarizer can distinguish left-handed and right-handed circularly polarized light, it is necessary to manually adjust the quarter-wave plate or polarizer to observe the change of light intensity during the process of distinguishing, and left-handed and right-handed circularly polarized light Circularly polarized light is not separated in space, which is not conducive to distinguishing the chirality of circularly polarized light intuitively in real time

This method utilizes traditional optical components and is not conducive to the miniaturization and integration of devices

[0005] The spatial separation of left-handed and right-handed circularly polarized light can be achieved by using the photonic spin Hall effect, but due to the very weak spin Hall effect, the separation distance between left-handed and right-handed circularly polarized light is very small, the maximum is only a micron level, requires a complex observation system, which is not conducive to intuitive observation, and cannot achieve miniaturization and integration

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