Birefringent phase control super-surface unit and broadband polarization and phase control array and device

Abstract

The invention discloses a broadband polarization and phase control array based on a birefringent super-surface structure. The broadband polarization and phase control array comprises a substrate, a metal reflection film, a medium layer, a cross sub-wavelength optical antenna unit, a birefringent phase control super-surface structure unit and a birefringent phase control super-surface structure array. According to a reasonable design, the birefringent phase control super-surface structure unit has a birefringent effect and a phase control function, and under incident conditions of circularly polarized light, the reflected light further has polarization control and phase control functions of space sub-wavelength resolution; and with respect to the circularly polarized incident light, the birefringent phase control super-surface structure units are arranged to form a birefringent phase control super-surface structure array according to the needed space polarization and phase distributionin order to obtain a special optical field with any polarization and phase distribution. Moreover, the birefringent phase control super-surface structure unit and the birefringent phase control super-surface structure array have wide operating wavelength ranges.

Description

technical field [0001] The invention belongs to the fields of light focusing, light imaging and light field regulation, and in particular relates to a complex vector light field regulation device for independent regulation of polarization and phase. Background technique [0002] For conventional superdiffraction lenses, binary amplitude modulation or quasi-continuous amplitude modulation is usually used, which often cannot achieve good focusing performance. The focusing efficiency is low and the side lobe intensity is too large, which seriously limits its further development. Far-field superdiffraction focusing is the result of precise interference of light waves, so it is very necessary to introduce phase control into the device transmittance function in device design and implementation. The sub-wavelength structure based on multi-valued phase control can significantly improve the focusing performance of superdiffraction focusing devices, such as reducing the far-field focu...

AI Technical Summary

Problems solved by technology

At the same time, the use of special polarized beams to focus is beneficial to further improve the performance of superdiffraction focusing. For example, for the focusing of cylindrically symmetrical polarized light, a separate polarization conversion device is usually used to generate the required angular or radially polarized light, and then through traditional lenses or super Diffraction lens focusing needs to align the optical axis of the angular or radially polarized beam with the optical axis of the focusing device, which greatly increases the difficulty of optical alignment and limits the improvement of super-diffraction focusing performance

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