阅读说明：本技术 一种偏振可调光谱双重差异性响应的完美光学吸波器及其制备方法 (Polarization-adjustable spectrum dual-difference-response perfect optical wave absorber and preparation method thereof ) 是由 刘正奇 刘桂强 钟浩宗 周进 刘晓山 刘木林 于 2019-10-14 设计创作，主要内容包括：本发明提供了一种偏振可调光谱双重差异性响应的完美光学吸波器及其制备方法。该完美光学吸波器包括金属基底层、非金属介质层和超表面结构层,非金属介质层连接于金属基底层上表面,超表面结构层连接于非金属介质层上表面；其中,超表面结构层由若干矩形纳米结构周期排列组成,每个矩形纳米结构由三层相同大小的矩形非金属介质叠加组成,其材料从上到下依次为硅、二氧化硅、硅。超表面结构层的谐振腔与入射光具有强的光场耦合作用,吸收器可以实现明显偏振可调特性的双频完美吸收,同时获得偏振不敏感和偏振敏感吸收。本发明为高折射率介质谐振器和超材料的光学特性和共振行为的偏振处理提供了新的视角。(The invention provides a polarization-adjustable spectrum dual-difference response perfect optical wave absorber and a preparation method thereof. The perfect optical wave absorber comprises a metal substrate layer, a non-metal medium layer and a super-surface structure layer, wherein the non-metal medium layer is connected to the upper surface of the metal substrate layer, and the super-surface structure layer is connected to the upper surface of the non-metal medium layer; the super-surface structure layer is formed by periodically arranging a plurality of rectangular nano structures, each rectangular nano structure is formed by overlapping three layers of rectangular non-metal media with the same size, and the rectangular non-metal media are made of silicon, silicon dioxide and silicon from top to bottom in sequence. The resonant cavity of the super-surface structural layer has a strong optical field coupling effect with incident light, and the absorber can realize double-frequency perfect absorption with obvious polarization adjustable characteristic and simultaneously obtain polarization insensitivity and polarization sensitive absorption. The invention provides a new view angle for polarization processing of optical characteristics and resonance behaviors of the high-refractive-index dielectric resonator and the metamaterial.)

1. A perfect optical wave absorber with polarization-adjustable spectrum dual difference response is characterized in that: the metal substrate layer, the nonmetal dielectric layer and the super-surface structure layer are included, the nonmetal dielectric layer is connected to the upper surface of the metal substrate layer, and the super-surface structure layer is connected to the upper surface of the nonmetal dielectric layer; the super-surface structure layer is formed by periodically arranging a plurality of rectangular nano structures, each rectangular nano structure is formed by overlapping three layers of rectangular non-metal media with the same size, and the rectangular non-metal media are made of silicon, silicon dioxide and silicon from top to bottom in sequence.

2. The perfect optical wave absorber of dual differential response of polarization tunable spectrum according to claim 1, wherein: the metal substrate layer is made of opaque metal, and the non-metal dielectric layer is made of silicon dioxide.

3. A perfect optical wave absorber of polarization tunable dual differential spectral response according to claim 1 or 2, wherein: the three layers of rectangular non-metal media with the same size are all 300-400 nanometers long, 150-200 nanometers wide and 50 nanometers thick.

4. The perfect optical wave absorber of polarization tunable spectral dual differential response of claim 3, wherein: the thickness of the metal substrate layer is 200-300 nanometers, and the thickness of the non-metal dielectric layer is 50 nanometers.

5. The perfect optical wave absorber of polarization tunable spectral dual differential response of claim 3, wherein: the opaque metal is gold, silver, copper or aluminum.

6. The method for preparing a perfect optical wave absorber with dual differential responses of polarization tunable spectrum according to claim 1, comprising the following steps:

step 1, preparing a clean metal substrate;

step 2, sequentially plating a first silicon dioxide film, a first silicon film, a second silicon dioxide film and a second silicon film on the metal substrate by using a plating technology;

and 3, etching the second silicon film, the second silicon dioxide film and the first silicon film to obtain a rectangular nano structure in periodic arrangement, namely obtaining the perfect optical wave absorber with polarization-adjustable spectrum dual differential response.

7. The method of claim 6, wherein: the coating technology is a magnetron sputtering method, an electron beam evaporation method, a pulse laser deposition method or an atomic layer deposition method.

8. The method according to claim 6 or 7, characterized in that: the etching is electron beam etching or focused ion beam etching.

Technical Field

The invention relates to the field of metamaterials, in particular to a polarization-adjustable spectrum dual-difference response perfect optical wave absorber and a preparation method thereof.

Background

With the rapid development of modern science and technology, more and more structures with novel optical characteristics and height-adjustable methods are available on the nanoscale, which has attracted people's extensive interest. In recent years, plasmonic metal nanostructures have received much attention due to their local field enhancement and coupling of intense optical fields with illumination light. These characteristics ultimately lead to the emerging potential applications of perfect absorbers and graphene-related near-perfect absorbers, solar energy collection, thermal evaporation techniques, surface enhanced spectroscopy, and sensing. The optical properties of the plasmon resonance cavity are mainly determined by the size, shape and surrounding medium. When the system has asymmetric characteristics, such as grating, patch and the like, it is feasible to form a polarization-sensitive plasma resonance structure; conversely, when the structure has a high degree of geometric symmetry, polarization independent resonant absorption can also be achieved. However, most existing metamaterial structures are only polarization dependent or polarization independent absorption, and tunable polarization absorption is not realized.

In recent years, metamaterial absorbers formed of metal/insulator layered structures have been proposed for narrow band, broadband or multiband light absorption. Since solar light has different polarization states, most of the research is directed to producing polarization independent absorption. To achieve this, highly symmetrical structural features are necessary. For example, resonators consisting of discs or spheres are used in square or hexagonal arrays to form spatially symmetric absorbers, exhibiting highly polarization insensitive absorption. However, absorbers for optoelectronic devices are generally required to have high tunable absorption properties. Inspired by this purpose, an asymmetric structure can be used to construct the polarization dependent absorber. On the basis of a metal resonance structure, the single-band or multi-band absorption with adjustable polarization is obtained by using an asymmetric system. However, these absorption bands all generally follow the same tunable behavior. That is, the polarization dependent response is performed over multiple bands. In many applications, absorbers are required whose absorption bands respond differently to the degree of polarization of incident light. Therefore, in order to achieve further manual manipulation control of the optoelectronic device, the behavior of introducing dual-frequency absorption of different polarization responses is necessary.

Disclosure of Invention

The invention aims to provide a polarization-adjustable spectrum dual-difference response perfect optical wave absorber and a preparation method thereof.

The invention provides a polarization-adjustable spectrum dual-difference response perfect optical wave absorber which comprises a metal substrate layer, a nonmetal medium layer and a super-surface structure layer, wherein the nonmetal medium layer is connected to the upper surface of the metal substrate layer; the super-surface structure layer is formed by periodically arranging a plurality of rectangular nano structures, each rectangular nano structure is formed by overlapping three layers of rectangular non-metal media with the same size, and the rectangular non-metal media are made of silicon, silicon dioxide and silicon from top to bottom in sequence.

Furthermore, the metal substrate layer is made of opaque metal, and the non-metal dielectric layer is made of silicon dioxide.

Further, the three layers of rectangular non-metal media with the same size are all 300-400 nanometers long, 150-200 nanometers wide and 50 nanometers thick.

Further, the thickness of the metal substrate layer is 200-300 nanometers, and the thickness of the non-metal dielectric layer is 50 nanometers.

Further, the opaque metal may be gold, silver, copper or aluminum.

The preparation method of the perfect optical wave absorber with the polarization-adjustable spectrum dual difference response comprises the following steps:

step 1, preparing a clean metal substrate;

step 2, sequentially plating a first silicon dioxide film, a first silicon film, a second silicon dioxide film and a second silicon film on the metal substrate by using a plating technology;

and 3, etching the second silicon film, the second silicon dioxide film and the first silicon film to obtain a rectangular nano structure in periodic arrangement, namely obtaining the perfect optical wave absorber with polarization-adjustable spectrum dual differential response.

Furthermore, the coating technology is a magnetron sputtering method, an electron beam evaporation method, a pulse laser deposition method or an atomic layer deposition method.

Further, the etching is electron beam etching or focused ion beam etching.

The invention has the beneficial effects that: the perfect optical wave absorber with the polarization-adjustable spectrum dual difference response can realize dual-frequency perfect absorption and simultaneously obtain polarization insensitivity and polarization sensitive absorption; a new view angle is provided for polarization processing of optical characteristics and resonance behaviors of the high-refractive-index dielectric resonator and the metamaterial; the method has wide application prospect in multifunctional devices such as photoelectrons, nonlinear optics, control modulators and detectors.

Drawings

Fig. 1 is a schematic perspective view of a perfect optical wave absorber with dual differential responses of polarization tunable spectrum according to the present invention.

Fig. 2 is a schematic cross-sectional structural diagram of a perfect optical wave absorber with dual differential responses of polarization tunable spectrum according to the present invention.

Fig. 3 is an absorption spectrum of a perfect optical wave absorber with dual differential responses of polarization tunable spectrum according to embodiment 3 of the present invention under incident light with different polarization degrees.

Fig. 4 is a graph illustrating the variation of the reflectivity intensity of the perfect optical wave absorber with dual differential responses of polarization tunable spectrum according to embodiment 3 of the present invention under incident light with different polarization degrees.

Fig. 5 is a graph illustrating changes in wavelength positions corresponding to absorption peaks when the polarization angle of incident light changes from 0 to 90 degrees in the perfect optical absorber with dual differential responses of polarization tunable spectra in embodiment 3 of the present invention.

Fig. 6 and 7 are absorption spectrograms corresponding to the polarization tunable spectrum dual difference response perfect optical wave absorbers in embodiments 1 to 9 of the present invention.

Detailed Description

The polarization-adjustable spectrum dual-difference response perfect optical wave absorber can be prepared according to the following steps:

step 1, preparing a clean metal substrate;

step 2, sequentially plating a first silicon dioxide film, a first silicon film, a second silicon dioxide film and a second silicon film on the metal substrate by using a magnetron sputtering film plating technology;

and 3, performing electron beam etching or focused ion beam etching technology on the second silicon film, the second silicon dioxide film and the first silicon film to obtain a periodically arranged rectangular nanostructure, and thus obtaining the perfect optical wave absorber with polarization-adjustable spectrum dual differential response.

As shown in fig. 1 and 2, the obtained perfect optical wave absorber with polarization-adjustable spectrum dual-difference response is sequentially provided with a metal substrate layer 1, a nonmetal medium layer 2 (namely, a first silicon dioxide film) and a super-surface structure layer 3 from bottom to top, wherein the nonmetal medium layer 2 is connected to the upper surface of the metal substrate layer 1, and the super-surface structure layer 3 is connected to the upper surface of the nonmetal medium layer 2. The super-surface structure layer 3 is formed by periodically arranging rectangular nano structures 4, each rectangular nano structure 4 is formed by overlapping three rectangular non-metal media with the same size, and the materials of the rectangular non-metal media are silicon, silicon dioxide and silicon from top to bottom in sequence; each layer of rectangular non-metallic medium has a length of 300-400 nm, a width of 150-200 nm and a thickness of 50 nm.

And changing the etching conditions to form the rectangular nano structures with different sizes. The following table shows the dimensional parameters of the polarization tunable spectroscopic dual differential response perfect optical wave absorbers of examples 1-9.

Fig. 3 is an absorption spectrum of a perfect optical wave absorber with polarization tunable spectrum dual differential response of example 3 at incident light polarization angles of 0 ° and 90 °. Wherein the length and width of the rectangular nanostructure are set to 350 nm and 175 nm, respectively, and the thickness of each layer of the rectangular nanostructure is 50 nm; the thickness of the non-metal dielectric layer is 50 nanometers; the thickness of the metal base layer was 200 nm.

In fig. 3, the solid line is an absorption spectrum of an incident light with a polarization angle of 0 °, and two absorption peaks can be seen therein. When the polarization angle is changed to 90 deg., the absorption spectrum shows only one absorption peak (dotted line in the figure). The absorption peak of long wavelength decreases with the increase of the polarization angle until disappearing, showing polarization sensitive absorption; while the absorption peak at short wavelengths is almost unchanged, showing polarization insensitive absorption.

Fig. 4 is a graph illustrating the variation of the reflectivity intensity of the perfect optical wave absorber with dual differential responses of polarization tunable spectrum in example 3 under incident light with different polarization degrees. The graph can be seen as the change of the reflectivity intensity corresponding to the two absorption peaks when the polarization angle is changed from 0 degrees to 90 degrees; and to the long wavelength absorption peak reflectivity change versus the intensity change curve of an idealized polarization response based on Malus' law. It can be seen from the figure that long wavelength exhibits a quantitatively controllable absorption response as the polarization angle changes; whereas short wavelengths correspond substantially independent of polarization angle changes. I.e. a dual band perfect light absorption under polarization control exhibiting dual diversity.

Fig. 5 is a graph illustrating the change of the wavelength position corresponding to the absorption peak when the polarization angle of the incident light changes from 0 to 90 degrees in the perfect optical wave absorber with dual differential responses of the polarization tunable spectrum in example 3. A change diagram of the wavelength positions of the absorption peaks corresponding to the two absorption peaks when the polarization angle is changed from 0 to 90 degrees; the position of the spectrum at the long-wavelength absorption peak is not changed, while the position of the absorption peak at the short-wavelength absorption peak is changed, but the front and back positions are only changed in the spectrum range of 3 nanometers, and the spectrum fluctuation is basically the spectrum fluctuation of the resonance absorption peak. These demonstrate that such absorbers maintain good spectral wavelength stability over the resonant absorption peak spectral range.

Fig. 6 and 7 are absorption spectra corresponding to the polarization tunable spectrum dual differential response perfect optical wave absorbers (with the change of metamaterial structure parameters) in examples 1 to 9. It can be seen from the figure that the resonant absorption intensity and the spectral operating wavelength of the absorber can be further regulated and controlled by changing the structural parameters. It can be seen that when the length and width of the rectangular metamaterial structure are increased, the absorption peak is red-shifted, and the absorption intensity is changed accordingly. Fig. 6 and 7 illustrate that the polarization-tunable spectrum dual differential response perfect optical wave absorber has a wide application prospect in the fields of tunable photoelectric detection, photoelectric conversion, photo-generated electron and thermal electron generation and collection.

In summary, high index media, such as semiconductors, have the ability to resonantly couple with incident light to create plasmons, similar to noble metals. Electromagnetic waves are incident to the super-surface structure layer and are in resonance coupling with the super-surface structure of the silicon layer. When the system has asymmetric characteristics, the system can realize polarization-dependent absorption; conversely, when the structure has a high degree of geometric symmetry, polarization independent resonant absorption can also be achieved. The perfect optical wave absorber with the polarization-adjustable spectrum dual difference response realizes dual-frequency perfect absorption, the absorption peak polarization at the short wavelength is not sensitive to absorption, and the absorption peak polarization at the long wavelength is sensitive to absorption; simultaneously, polarization sensitive and polarization insensitive absorption are obtained; the resonance absorption intensity and the spectrum working wavelength of the absorber can be further adjusted by adjusting the structural parameters of the super-surface structural layer; a new view angle is provided for polarization processing of optical characteristics and resonance behaviors of the high-refractive-index dielectric resonator and the metamaterial; the application of the tunable optical wave absorber is expanded, and the tunable optical wave absorber has wide application prospects in the fields of nonlinear optics, control modulators, detectors, photoelectric detection, photoelectric conversion, photo-generated electron and thermal electron generation and collection.

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.