阅读说明：本技术 一种实现圆二色性的异质金属网状超材料结构 (Heterogeneous metal mesh metamaterial structure for realizing circular dichroism ) 是由 郭小伟 秦茂森 蒋婷 郑慧宜 李绍荣 于 2021-03-16 设计创作，主要内容包括：本发明涉及微纳光学技术领域,具体涉及一种实现圆二色性的异质金属网状超材料结构,该结构包括衬底1、和位于衬底1上的金属层2组成。金属层包含金属光栅3和金属光栅4组成,所述金属光栅3与金属光栅4彼此以相交但互不垂直,所述金属光栅4被金属光栅3截断成周期的纳米棒阵列。本发明一种实现圆二色性的异质金属网状超材料结构,可以产生吸收的圆二色信号,最大值可以达到40％,并且可以通过调节光栅周期、占空比从而对圆二色性进行动态调节；另外一点就是,该实现圆二色性的异质金属网状超材料结构制备方法简单,制备成本低,具有很好的应用前景。(The invention relates to the technical field of micro-nano optics, in particular to a heterogeneous metal mesh metamaterial structure for realizing circular dichroism, which comprises a substrate 1 and a metal layer 2 positioned on the substrate 1. The metal layer comprises a metal grating 3 and a metal grating 4, the metal grating 3 and the metal grating 4 are intersected with each other but not perpendicular to each other, and the metal grating 4 is intercepted by the metal grating 3 to form a periodic nanorod array. The heterogeneous metal mesh metamaterial structure for realizing circular dichroism can generate absorbed circular dichroism signals, the maximum value can reach 40%, and the circular dichroism can be dynamically adjusted by adjusting the grating period and the duty ratio; in addition, the heterogeneous metal mesh metamaterial structure for realizing circular dichroism is simple in preparation method, low in preparation cost and good in application prospect.)

1. A heterogeneous metal mesh metamaterial structure for realizing circular dichroism is characterized in that the metal mesh structure is arranged on a substrate and is formed by mutually intersecting two groups of metal gratings with different materials.

2. The heterogeneous metal mesh metamaterial structure for realizing circular dichroism of claim 1, wherein the two sets of metal grating materials are respectively two different metals.

3. The heterogeneous metal mesh metamaterial structure implementing circular dichroism as claimed in claim 2, wherein the two sets of metal gratings of different materials intersect each other but are not perpendicular to each other, wherein one set of gratings is truncated by the other set of gratings to form a nanorod array.

4. A heterogeneous metal mesh metamaterial structure capable of realizing circular dichroism as claimed in claim 1, wherein the thicknesses of the two sets of gratings in the heterogeneous metal mesh metamaterial structure can take different values.

5. A heterogeneous metal mesh metamaterial structure for realizing circular dichroism as claimed in claim 1, wherein the two sets of metal gratings have different periods and different metal line widths.

6. The heterogeneous metal mesh metamaterial structure for realizing circular dichroism, according to claim 1, wherein the two sets of metal gratings are inclined at an acute angle to each other.

7. The heterogeneous metal mesh metamaterial structure capable of achieving circular dichroism of claim 1, wherein the substrate can be made of different materials to adjust circular dichroism.

Technical Field

The invention relates to the technical field of micro-nano optics, in particular to a heterogeneous metal mesh metamaterial structure for realizing circular dichroism.

Background

Chiral refers to the property of not being completely coincident with a mirror image by itself, where a chiral species and its mirror image are referred to interchangeably as the chiral counterparts. Many substances in nature have chirality in their structure, such as proteins, DNA, etc. The chirality is of great importance to life, so that the detection of chirality of substances becomes a hot spot for research of numerous researchers. Circular Dichroism (CD), which can be defined as the difference in absorption rate of a chiral medium for different circularly polarized light, is generally used to detect the chirality of a substance or structure.

Since chiral signals such as biomolecules are weak and generally located in a near ultraviolet band, which is inconvenient to detect, it is very important to further understand the chiral nature and the nature of circular dichroism by studying the nature of the chiral structure of the artificial metal.

The traditional metal chiral structure for realizing circular dichroism mostly adopts a multilayer structure, the multilayer chiral structure generally has good circular dichroism, but the structure is complex, so that the preparation is generally difficult in an experiment, and the difficulty in actual production and manufacturing is higher. Compared to multilayer structures, single-layer chiral structures are easier to prepare, but some optical structures provided in the prior art consist of a single medium, a complex single-layer structure needs to be designed to achieve the chiral effect, which greatly increases the difficulty of manufacturing the optical structures, and circular dichroism is generally weak.

Disclosure of Invention

In view of the above problems, the present invention is directed to a technical problem of how to design a micro-nano structure capable of realizing strong circular dichroism.

Therefore, the invention provides a heterogeneous metal mesh metamaterial structure for realizing circular dichroism, which comprises a substrate, wherein a metal structure layer is arranged on the substrate; the metal structure layer comprises two groups of metal gratings, the two groups of metal gratings are mutually intersected but not mutually perpendicular, and one group of metal gratings is cut off by the other group of metal gratings to form a periodic nanorod array.

Furthermore, the two groups of metal gratings are respectively composed of two different metals.

Further, the thicknesses of the two groups of gratings of the heterogeneous metal mesh metamaterial structure can be different from each other.

Further, the two metal grating periods T1 and T2 may be different, and the respective metal line widths w1 and w2 may also be different.

Furthermore, the included angle of the two groups of metal grating periods is an acute angle.

Further, the substrate may be made of different materials.

Compared with the prior art, the invention has the beneficial effects that:

1. the optical structure for enhancing circular dichroism of circularly polarized light provided by the invention has good circular dichroism, can improve the circular dichroism to about 40%, enables the circular dichroism to be more prominent, lays a foundation for the application of the circular dichroism, and can dynamically adjust the circular dichroism by setting different periods, metal wire widths and included angles;

2. the optical structure for enhancing circular dichroism of circularly polarized light has the advantages of simple preparation method and low preparation cost, and has good application prospect when being used as a detection component of a high-sensitivity biological chiral structure.

The present invention will be described in further detail with reference to the accompanying drawings

Drawings

FIG. 1 is a schematic plan view of a heterogeneous metal mesh metamaterial structure according to the present invention; .

FIG. 2 is an absorption spectrum of the heterogeneous metal mesh metamaterial structure of example 1;

FIG. 3 is a circular dichroism plot of the heterogeneous metal mesh metamaterial structure of example 1;

Detailed Description

The method aims to solve the problems that in the prior art, a three-dimensional metal micro-nano structure is difficult to prepare and a two-dimensional metal micro-nano structure CD signal is generally weak. The heterogeneous metal mesh metamaterial structure for realizing circular dichroism can generate absorbed circular dichroism signals, and the maximum value can reach 40%. To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined purpose, the following detailed description, structural features and effects of the present invention are provided with reference to the accompanying drawings and examples, but the present invention is not limited thereto.

Example 1 was carried out:

the embodiment provides a heterogeneous metal mesh metamaterial structure shown in fig. 1, which includes a substrate 1, wherein the substrate 1 mainly plays a manufacturing role, the substrate 1 is made of silicon dioxide, a gold grating 2 and a silver grating 3 which are arranged on the substrate 1 are intersected with each other but not perpendicular to each other, and the silver grating 3 is cut by the gold grating 2 to form a silver nanorod array;

furthermore, the periods and the metal line widths of the gold gratings and the silver gratings are respectively 400nm and 140nm, and the included angle between the gratings is 65 degrees. The thickness of the metal layer is 50 nm.

To further illustrate the circular dichroism characteristics of the heterogeneous metal mesh metamaterial in example 1, the example discloses a transmission spectrum and a circular dichroism spectrum under the irradiation of left-handed and right-handed circular polarized light, as shown in fig. 2 and 3. Circular dichroism of the structure can reach 40% at most.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.