A full-dielectric transmission metasurface full-phase controller

Abstract

The present invention discloses an all-dielectric transmission type metasurface full-phase regulator, comprising the periodically arranged particles, the coating and the substrate, wherein the coating, the periodically arranged periodically arranged particles and the substrate are arranged in overlapping order from top to bottom, the periodically arranged particles include the horizontal arm and the vertical arm, and the transmission spectrum distribution is observed by changing the length of the horizontal arm, and the transmission spectrum obtained by finally determining the length of the horizontal arm has an average transmittance of up to 80.3%. In this way, a high transmission efficiency can be achieved through a simple structure, and a phase regulation of 0 to 2π can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of micro-nano optics, and in particular to an all-medium transmission type metasurface all-phase regulator. Background Art

[0002] In the current research and application of modern optics, metasurfaces are attracting more and more attention from researchers due to their ultra-thin structure and ability to precisely control electromagnetic fields. Metasurfaces are a special type of ultra-thin artificial electromagnetic metamaterial that can flexibly and effectively control the phase, polarization mode, propagation mode and other characteristics of electromagnetic waves at a subwavelength scale, thereby achieving functions such as focused imaging, anomalous deflection, perfect absorption and polarization rotation. Compared with traditional "bulk metamaterials", metasurfaces have significant advantages such as small size, thin thickness, easy preparation and integration. At the same time, they are also more flexible and precise in controlling light. However, the discrete antenna array structure has the defect of low structural tolerance, which blocks the transmission of some particles, resulting in low transmittance of existing phase regulators. Summary of the invention

[0003] The purpose of the present invention is to provide a full-dielectric transmission metasurface full-phase regulator, aiming to solve the technical problem that the discrete antenna array structure in the prior art has a low structural fault tolerance, blocks the transmission of some particles, and thus leads to low transmittance of the existing phase regulator.

[0004] To achieve the above-mentioned purpose, the present invention adopts an all-dielectric transmission type metasurface full-phase regulator, including a substrate, a coating and periodically arranged particles; the coating is fixedly connected to the substrate and is located on one side of the substrate, and the periodically arranged particles are fixedly connected to the substrate and are located inside the coating; the horizontal arm and the vertical arm are fixedly connected to the substrate and are located inside the coating, one end of the vertical arm is fixedly connected to the horizontal arm, and the other end faces in a direction away from the horizontal arm, and is T-shaped.

[0005] The material of the horizontal arm and the vertical arm is GaAs, the material of the coating is BaF2, and the material of the substrate is SiO2.

[0006] The thickness of the coating is h1=500nm, the thickness of the substrate is h2=200nm, the thickness of the horizontal arm and the vertical arm are the same, which is h3=400nm, and the width of the horizontal arm is w x =140nm, the width of the vertical arm is w y =150nm, length l y =250nm.

[0007] Wherein, the length of the horizontal arm is l x =510nm.

[0008] Wherein, the period of the horizontal arm and the vertical arm is P x =P y =1000nm.

[0009] Among them, the operating wavelength of the all-dielectric transmission type metasurface full-phase regulator is 1400-1600nm.

[0010] The present invention discloses an all-dielectric transmission type metasurface full-phase regulator, comprising the periodically arranged particles, the coating and the substrate, wherein the coating, the periodically arranged periodically arranged particles and the substrate are arranged in overlapping order from top to bottom, and the periodically arranged particles include the horizontal arm and the vertical arm. The transmission spectrum distribution is observed by changing the length of the horizontal arm, and the transmission spectrum obtained by finally determining the length of the horizontal arm has an average transmittance of up to 80.3%. In this way, a high transmission efficiency can be achieved through a simple structure, and phase regulation of 0 to 2π can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 It is a three-dimensional schematic diagram of the geometric structure of the all-dielectric transmission metasurface all-phase regulator of the present invention.

[0013] Figure 2 It is a schematic diagram of the three-dimensional structure of the periodically arranged T-shaped nanoparticles of the all-dielectric transmission metasurface all-phase regulator of the present invention.

[0014] Figure 3 It is the transmission spectrum of the all-medium transmission type metasurface all-phase regulator of the present invention.

[0015] Figure 4 It is a structural schematic diagram of the electric field phase distribution diagram of the xz cross section when the working wavelength is 1500nm.

[0016] Figure 5 It is the influence of the change of the horizontal arm length of periodically arranged particles on the phase of the transmitted wave.

[0017] In the figure: 1-substrate, 2-coating, 3-periodically arranged particles, 31-horizontal arm, 32-vertical arm, 100-all-dielectric transmission type metasurface full-phase regulator. DETAILED DESCRIPTION

[0018] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0019] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0020] In the first example of this embodiment:

[0021] See also Figures 1 to 5 The present invention provides an all-dielectric transmission metasurface all-phase regulator 100, comprising a substrate 1, a coating 2 and periodically arranged particles 3; the coating 2 is fixedly connected to the substrate 1 and is located on one side of the substrate 1, the periodically arranged particles 3 are fixedly connected to the substrate 1 and are located inside the coating 2; the periodically arranged particles 3 include a horizontal arm 31 and a vertical arm 32, the horizontal arm 31 and the vertical arm 32 are fixedly connected to the substrate 1 and are located inside the coating 2, one end of the vertical arm 32 is fixedly connected to the horizontal arm 31, and the other end faces a direction away from the horizontal arm 31, and is T-shaped.

[0022] Furthermore, the material of the horizontal arm 31 and the vertical arm 32 is GaAs, the material of the coating 2 is BaF2, and the material of the substrate 1 is SiO2.

[0023] Furthermore, the thickness of the coating 2 is h1=500nm, the thickness of the substrate 1 is h2=200nm, the thickness of the horizontal arm 31 and the vertical arm 32 are the same, which is h3=400nm, and the width of the horizontal arm 31 is w x =140nm, the width of the vertical arm 32 is w y =150nm, length l y =250nm.

[0024] Furthermore, the length of the horizontal arm 31 is l x=510nm.

[0025] Furthermore, the period of the horizontal arm 31 and the vertical arm 32 is P x =P y =1000nm.

[0026] Furthermore, the operating wavelength of the all-dielectric transmission metasurface all-phase regulator 100 is 1400-1600 nm.

[0027] In this embodiment, the all-dielectric transmission type metasurface full phase regulator 100 is a periodic arrangement of nanoparticles, which is easy to realize through nano-processing technology. The metasurface structure includes the substrate 1 and the coating 2, and the periodically arranged particles 3 periodically arranged on the substrate 1. The coating 2, the periodically arranged periodically arranged particles 3 and the substrate 1 are arranged in overlapping order from top to bottom. The periodically arranged horizontal arm 31 and the vertical arm 32 are made of GaAs, the coating 2 on the substrate 1 is made of BaF2, and the substrate 1 is made of SiO2. The all-dielectric transmission type metasurface full phase regulator 100 realizes phase regulation through the optical path difference generated by the electromagnetic wave during the propagation process. For a uniform medium, assuming that the refractive index is n and the distance propagated by the electromagnetic wave with a wavelength of λ0 is d, the accumulated transmission phase during the propagation process is:

[0028]

[0029] For an electromagnetic wave of a fixed wavelength, in order to produce a phase mutation, the parameters that can be adjusted are the refractive index n of the medium transmitting the electromagnetic wave and the transmission distance, that is, the thickness d of the medium.

[0030] The specific design method is to first determine the basic shape of the nanoparticles. This design is a T-shaped structure, which is periodically arranged to form a uniform metasurface. The geometric structure is changed while observing the phase of the transmitted light passing through the uniform metasurface to obtain a curve of the change of the transmitted light phase with the geometric structure of the nanoparticles. By performing a parameter scan on the length of the horizontal arm 31 of the T-shape, changing other structural parameters and observing the influence on the transmission phase, the optimized parameters are obtained. The thickness of the coating 2 is h1=500nm, and the thickness of the substrate 1 is h2=200nm. The horizontal arm 31 and the vertical arm 32 of the periodically arranged periodically arranged particles 3 have the same thickness, which is h3=400nm, and the width of the horizontal arm 31 is w x =140nm, the width of the vertical arm 32 is w y =150nm, length l y =250nm. The period of this periodic structure is P x =P y=1000nm. The working wavelength of the all-dielectric transmission type metasurface all-phase regulator 100 is 1400-1600nm.

[0031] Figure 4 In order to select the distribution of the electric field phase of the xz section when the working wavelength is 1500nm, UC in the figure represents the all-dielectric transmission type metasurface full-phase regulator 100 described in this embodiment, and select the point with coordinates z=-2000nm, x=0nm, and observe its phase through the monitor. Figure 5 The effect of the change of the length and wavelength of the horizontal arm 31 of the periodically arranged particles 3 on the phase of the point in this embodiment is given. As can be seen from the figure, within the working wavelength range, by changing the length of the horizontal arm 31 within the range of 300 to 700 nm, the phase of the point can be distributed within 0 to 2π.

[0032] Through FDTD Solutions simulation calculation, Figure 3 The transmission spectrum of this embodiment is given. The distribution of the transmission spectrum is observed by changing the length of the horizontal arm 31. Finally, it is determined that the transmission spectrum obtained when the length of the horizontal arm 31 is 510nm has an average transmittance of up to 80.3%. The structure is relatively simple and easy to implement. In this way, it can have a higher transmission efficiency and achieve phase control of 0 to 2π.

[0033] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. An all-dielectric transmission metasurface full-phase regulator, characterized in that: including substrate, coating and periodically arranged particles; The coating is fixedly connected to the substrate and is located on one side of the substrate, and the periodically arranged particles are fixedly connected to the substrate and are located inside the coating; The periodically arranged particles include a horizontal arm and a vertical arm, wherein the horizontal arm and the vertical arm are fixedly connected to the substrate and are located inside the coating, and one end of the vertical arm is fixedly connected to the horizontal arm, and the other end faces away from the horizontal arm and is in a T-shape; The material of the horizontal arm and the vertical arm is GaAs, the material of the coating is BaF2, and the material of the substrate is SiO2; The operating wavelength of the all-dielectric transmission type metasurface all-phase regulator is 1400-1600nm.

2. The all-dielectric transmission metasurface all-phase controller according to claim 1, characterized in that: The thickness of the coating is h1=500nm, the thickness of the substrate is h2=200nm, the thickness of the horizontal arm and the vertical arm is the same, which is h3=400nm, and the width of the horizontal arm is w x =140nm, the width of the vertical arm is w y =150nm, length l y =250nm.

3. The all-dielectric transmission metasurface all-phase controller according to claim 2, characterized in that: The length of the horizontal arm is l x =510nm.

4. The all-dielectric transmission metasurface all-phase controller according to claim 3, characterized in that: The period of the horizontal arm and the vertical arm is P x =P y =1000nm.

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