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CN-121995561-A - Dual-functional super-surface for realizing efficient red light filtering and deflection and design method thereof

CN121995561ACN 121995561 ACN121995561 ACN 121995561ACN-121995561-A

Abstract

The invention discloses a dual-function super-surface for realizing efficient red light filtering and deflection and a design method thereof. The dual-function super-surface integrates the nano cavity and the trapezoid super-surface from bottom to top along the light propagation direction, the nano cavity is formed by stacking three layers of nano films, namely silicon, silicon dioxide and silicon, the trapezoid super-surface is formed by arranging a trapezoid silicon nano array on a silicon dioxide layer, and the dual-function super-surface can realize the function of high-efficiency red light selective deflection based on the high-transmissivity filtering function of the nano cavity in a red light wave band and full-phase regulation and control provided by the trapezoid super-surface. Meanwhile, the dual-function super surface can effectively adjust the working wave band by adjusting the thickness of the silicon dioxide layer of the nano cavity. The invention has the remarkable advantages of simple structure and convenient preparation, and has important application prospect in the fields of wavelength classification, spectrum analysis, optical imaging and the like.

Inventors

  • DAI CHENJIE
  • ZHOU QIANQIAN
  • LING CHEN
  • YU ZIJUN
  • ZHANG HUAFENG
  • DONG XIAOFENG
  • Xiao Zhuozhuang
  • CHEN YIXUAN

Assignees

  • 长江大学

Dates

Publication Date
20260508
Application Date
20260227

Claims (10)

  1. 1. A dual-functional super-surface for realizing efficient red light filtering and deflection is characterized in that: The double-function super-surface is vertically integrated by the nano cavity and the trapezoid super-surface in sequence from bottom to top along the light propagation direction; The nano cavity is formed by stacking three layers of nano films and sequentially comprises a lower dielectric layer, a silicon dioxide layer and an upper dielectric layer, wherein the lower dielectric layer and the upper dielectric layer are collectively called as an all-dielectric layer of the nano cavity, and the all-dielectric layer is made of any one of silicon, silicon nitride or titanium dioxide; The trapezoid super surface is a trapezoid silicon nano structure array arranged on the surface of the silicon dioxide layer, and the width of the trapezoid silicon nano structure along the x direction is in linear gradient change so as to realize continuous regulation and control of the phase.
  2. 2. The dual-function subsurface of claim 1, wherein the thickness of each layer of the microcavity and trapezoidal subsurface is sub-wavelength scale.
  3. 3. The dual-function subsurface of claim 2, wherein the trapezoid silicon nanostructure has an upper base width of 40nm to 60nm, a lower base width of 60nm to 120nm, a height of 830nm to 1000nm, and a thickness of 190nm to 350nm.
  4. 4. The dual-functional subsurface of claim 3, wherein the thickness of the upper and lower dielectric layers in the nanochamber is 20 nm-40 nm.
  5. 5. The dual-function subsurface of claim 4, wherein the period of the dual-function subsurface in the x-direction is 1000nm to 1200nm and the period in the y-direction is 200nm to 400nm.
  6. 6. A design method for realizing efficient red light filtering and deflection dual-function super-surface is characterized by comprising the following steps: S1, constructing a nano cavity structure, namely sequentially depositing a lower dielectric layer, a silicon dioxide layer and an upper dielectric layer to form a three-layer stacked nano cavity; s2, constructing a trapezoid super-surface, namely depositing a silicon dioxide layer on the surface of an upper dielectric layer of the nano cavity, and preparing a trapezoid silicon nanostructure array on the surface of the silicon dioxide layer to enable the width of the trapezoid silicon nanostructure to be in linear gradient change along the x direction; S3, parameter optimization, namely adjusting the size parameter of the trapezoid silicon nano structure and the cavity length of the nano cavity to enable the difunctional super surface to obtain complete 2 pi phase regulation capacity and red light wave band high-transmittance filtering characteristics; And S4, functional verification, namely confirming that the filtering and beam deflection performance of the dual-function super-surface meets the standard through electromagnetic field simulation or experimental test.
  7. 7. The method of claim 6, wherein the dimension parameters of the trapezoidal silicon nanostructures in step S2 are optimized according to the target operating wavelength, such that the trapezoidal silicon nanostructures provide complete 2pi phase modulation at the target wavelength.
  8. 8. The method of claim 7, wherein in step S3, the cavity length is adjusted by changing the thickness of the silicon dioxide layer in the nano cavity, so as to realize selective filtering of different working wavelengths in the visible light band, and the thickness adjustment range of the silicon dioxide layer is 120 nm-245 nm.
  9. 9. Use of a bifunctional superpurface according to any one of claims 1-5 for spectroscopic analysis, wherein light of different wavelengths is deflected to different angles by means of the 2 pi phase modulation capability of the bifunctional superpurface, enabling an accurate identification of the spectral components.
  10. 10. Use of a bifunctional subsurface as claimed in any of claims 1-5 in wavelength sorting or optical imaging wherein light of a specific wavelength is selectively filtered using the filter characteristics of the nanocavity and the remaining wavelength is reflected, and wherein the imaging function is achieved using the wavelength selective beam deflection characteristics in optical imaging.

Description

Dual-functional super-surface for realizing efficient red light filtering and deflection and design method thereof Technical Field The invention relates to the technical field of micro-nano optics and film optics, in particular to a dual-function super-surface for realizing efficient red light filtering and deflection and a design method thereof. Background The super-surface composed of nano-structures with different shapes provides a compact and planar solution for realizing light field regulation and control, and realizes multiple functions in the fields of achromatic focusing, high-capacity holographic multiplexing, dynamic structural colors and the like. By designing different types of super-surfaces and combining multiple physical mechanisms, the method is one of the most effective methods for improving the integration capability of the super-surfaces, for example, by designing Fabry-perot (FP) nano-cavities with different heights, filtering the same wavelength, and introducing modulation of transmission phase, phase encoding at a single wavelength can be realized. However, since both phase modulation and spectral selectivity are derived from the cavity length of the nanocavity, not only is the freedom of phase not achieved, but also complete decoupling of spectrum and phase is hindered. To solve such problems, an effective and simple method is to integrate FP nanocavity and phase-modulating supersurface in the direction of light propagation to preserve its spectral selectivity, thereby achieving light field modulation of any monochromatic light. However, typical FP microcavity structures, such as metal-insulator-metal three-layer nanofilm structures, present serious metal loss problems that limit the efficiency of the device. It remains a significant challenge to achieve high performance transmissive spectrally selective beam deflection using simple supersurfaces based on FP microcavity structures. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a dual-function super-surface for realizing efficient red light filtering and deflection and a design method thereof. By the method, the trapezoidal super surface can be integrated with the FP cavity along the light propagation direction, so that the super surface has the capacity of full 2 pi phase regulation and spectrum filtering, and the spectrum selective light beam deflection with high transmittance at the red light wave band is realized. In order to achieve the above purpose, the technical scheme of the invention is as follows: The invention provides a dual-function super-surface for realizing efficient red light filtering and deflection, which is formed by vertically integrating a nano cavity and a trapezoid super-surface in a sequence from bottom to top along a light propagation direction, wherein the nano cavity is formed by stacking three layers of nano films, namely a lower dielectric layer, a silicon dioxide layer and an upper dielectric layer, the lower dielectric layer and the upper dielectric layer are collectively called as all dielectric layers of the nano cavity, the all dielectric layers are made of any one of silicon, silicon nitride or titanium dioxide, the trapezoid super-surface is a trapezoid silicon nano-structure array arranged on the surface of the silicon dioxide layer, and the width of the trapezoid silicon nano-structure along the x direction is in linear gradient change so as to realize continuous regulation and control of a phase. Preferably, the thickness of each layer of the nano cavity and the trapezoid super surface is a sub-wavelength scale. Further, the width of the upper bottom of the trapezoid silicon nano structure is 40-60 nm, the width of the lower bottom is 60-120 nm, the height is 830-1000 nm, the thickness is 190-350 nm, the thicknesses of the upper dielectric layer and the lower dielectric layer (preferably silicon layers) in the nano cavity are 20-40 nm (preferably 30 nm), the period of the difunctional super surface in the x direction is 1000-1200 nm (preferably 1000 nm), and the period in the y direction is 200-400 nm (preferably 200 nm). In a second aspect, the present invention provides a method for designing a dual-function supersurface for efficient red light filtering and deflection, comprising the steps of: S1, constructing a nano cavity structure, namely sequentially depositing a lower dielectric layer, a silicon dioxide layer and an upper dielectric layer to form a three-layer stacked nano cavity; S2, constructing a trapezoid super-surface, namely depositing a silicon dioxide layer on the surface of an upper dielectric layer (preferably a silicon layer) of the nano cavity, preparing a trapezoid silicon nanostructure array on the surface of the silicon dioxide layer, enabling the width of the trapezoid silicon nanostructure to change in a linear gradient along the x direction, and optimizing the dimension parameters of the trapezoid silicon nanostructure according