152 results about "Terahertz metamaterials" patented technology

Metamaterial structures are taught which provide for the modulation of terahertz frequency signals. Each element within an array of metamaterial (MM) elements comprises multiple loops and at least one gap. The MM elements may comprise resonators with conductive loops and insulated gaps, or the inverse in which insulated loops are present with conductive gaps; each providing useful transmissive control properties. The metamaterial elements are fabricated on a semiconducting substrate configured with a means of enhancing or depleting electrons from near the gaps of the MM elements. An on to off transmissivity ratio of about 0.5 is achieved with this approach. Embodiments are described in which the MM elements incorporated within a Quantum Cascade Laser (QCL) to provide surface emitting (SE) properties.

Terahertz metamaterials comprise a periodic array of resonator elements disposed on a dielectric substrate or thin membrane, wherein the resonator elements have a structure that provides a tunable magnetic permeability or a tunable electric permittivity for incident electromagnetic radiation at a frequency greater than about 100 GHz and the periodic array has a lattice constant that is smaller than the wavelength of the incident electromagnetic radiation. Microfabricated metamaterials exhibit lower losses and can be assembled into three-dimensional structures that enable full coupling of incident electromagnetic terahertz radiation in two or three orthogonal directions. Furthermore, polarization sensitive and insensitive metamaterials at terahertz frequencies can enable new devices and applications.

The invention discloses a broadband terahertz metamaterial absorber based on L-shaped structures and belongs to the technical field of metamaterials and electromagnetic function materials. The broadband terahertz metamaterial absorber comprises a metal reflection layer, a dielectric layer and a metal pattern layer, the metal reflection layer is a continuous metal thin film, thickness of the metal reflection layer is larger than skin depth of working terahertz wave, the dielectric layer is positioned between the metal reflection layer and the metal pattern layer and is a silicon dioxide thin film, the metal pattern layer is formed by periodically arranging the L-shaped unit metamaterial structures, and each L-shaped unit metamaterial structure is formed by connecting a horizontal arm and a vertical arm which are perpendicular to each other. By reasonably designing geometric size and lattice period of the L-shaped structures and thickness of the dielectric layer in the middle, the characteristic that electromagnetic waves vertically coming to the surface of a metamaterial are absorbed completely can be realized. The broadband terahertz metamaterial absorber is simple in graph pattern and needless of stacking of multiple layers of materials, has characteristics of wide frequency band and high absorptivity and can be used for an electromagnetic wave collecting and detecting device.

The invention discloses a biological sample signal amplification method adopting the combination of terahertz metamaterials and nanogold particles. The method comprises the following steps: preparing a plurality of biological sample solutions with different concentrations and gold standard avidin solutions with different concentrations; dropwise adding the biological sample solutions onto the surfaces of the terahertz metamaterials, and airing at the room temperature; dropwise adding the gold standard avidin solutions on the surfaces of the terahertz metamaterials, and airing at the room temperature; collecting terahertz time-domain signals of all sample points to be measured on the surfaces of the terahertz metamaterials and reference sample points; calculating the transmissivity or the reflectivity of all the sample points to be measured and the reference sample points according to the terahertz time-domain signals; and calculating to obtain the frequency shift of transmission peaks or reflection peaks according to the frequency value corresponding to the lowest point of the transmissivity or the reflectivity. According to the method, the terahertz metamaterials and the nanogold particles are used for modifying; the sample signals are amplified by using an electric field local enhancement effect of the metamaterials; the electric field distribution effect is changed by nanogold, and the sample signals are further amplified by nanogold modifying; and the detection is high in sensitivity, the operation is convenient and fast, and fast detection requirements increased day by day are met.

The invention relates to a filter of tunable terahertz metamaterial and a preparation method thereof based on low-voltage-driven liquid crystal material with the aim of solving problems of an existing filter of tunable terahertz metamaterial such as fixed working wavelength, limited working bandwidth, narrow application scope, complicated structure and preparation technology and low reliability. The filter is in the structure of a multi-layer flat plate and comprises a glass substrate layer, a first metal structure layer, an insulation layer, a metal seed layer, a second metal structure layer, liquid crystal material and a glass cover plate. The preparation method comprises following steps: first, preparation of metal structure layers; second, preparation of the insulation layer; third, preparation of the metal seed layer; fourth, preparation of a mould structure used for electroplating; fifth, preparation of a periodic slit-metal structure; sixth, filling of liquid crystal material and covering with the glass cover plate. The filter of tunable terahertz metamaterial and the preparation method thereof based on low-voltage-driven liquid crystal material have following beneficial effects: the filter is low in needed voltage, simple in structure, wide in tuning range, high in response speed and good in chemical stability and is not sensitive to polarization; and the method is suitable for preparation of filter of tunable terahertz metamaterial filter of tunable terahertz metamaterial.

The invention provides a terahertz metamaterial device for detecting circulating tumor cells and a preparation method thereof. The device is mainly characterized with a stereo terahertz metamaterial,supplemented by a liquid diversion region. Only a small amount of blood sample is introduced from an inlet hole in a cover plate, and then blood cells of smaller size can be filtered according to structural features. Cancer cells of larger size are fixed at the sensitive positions, namely the clamping positions, of a metamaterial resonant structure. The cancer cells in the sample can be detected by comparing spectral changes before and after the sample is introduced. In addition, the device enables single separation of cancer cells, and can be used for subsequent biological study of individualcancer cells, so as to master the trait changes of each individual cancer cell stimulated by external conditions based on spectral analysis. Compared with the prior art, the device has high sensing sensitivity, and has remarkable effects when being used for fixed-point capture or large cell monitoring.

The invention discloses a modulation method and product of a terahertz metamaterial and belongs to the field of metamaterials. The method comprises the steps that firstly, a periodic cylindrical air cavity is formed in a substrate of a PDMS material, then a flexible medium PDMS thin film is arranged above the air cavity, and the metamaterial is arranged on the PDMS thin film; then, outside pressure is added, so that the flexible medium PDMS thin film above the air cavity is protruding or sunken, then geometric parameters of the metamaterial on the PDMS thin film are changed, and finally the response to the incident terahertz wave is modulated. The invention further provides the product which achieves the modulation method. The product comprises a metamaterial structure and a PDMS substrate, the metamaterial structure is arranged on the PDMS substrate, the metamaterial comprises the PDMS thin film and a two-dimension periodic array which is arranged on the PDMS thin film, and the periodic cylindrical air cavity is formed in the PDMS substrate. The modulation method is simple and reliable, is easily controlled, and is relatively high in modulation performance of the linearly polarized beam and the circularly polarized light.

The invention provides a multiband terahertz meta-material absorber, which belongs to the technical field of multiband terahertz meta-material absorbers and is used to solve the problem that high absorption of electromagnetic waves can be achieved only in a single, two or three frequency bands. The meta-material absorber of the invention is composed of a plurality of absorber units. Each absorberunit is composed of a bottom metal film 1, an intermediate loss medium 2 and a top metal film arranged in sequence from bottom to top, and the bottom metal film 1, the intermediate loss medium 2 and the top metal film cling to one another. The bottom metal film 1 is an all-metal film. The top metal film is an asymmetric metal split ring 3. The geometric center of the asymmetric metal split ring 3,the geometric center of the intermediate loss medium 2 and the geometric center of the bottom metal film 1 are in a straight line. By reasonably designing the geometric size and lattice period of theasymmetric metal split rings, electromagnetic waves vertically incident on the surface of a meta-material can be absorbed completely. The meta-material absorber provided by the invention has high absorption rate, is simple in structure, and has five absorbing peak points.

The invention discloses a terahertz metamaterial waver absorber with a proactively tunable frequency and a manufacturing method thereof. The wave absorber comprises a bottom structure, an intermediatedielectric layer and a top resonant structure. The bottom structure includes at least one metal film. The intermediate dielectric layer is fixed to the bottom structure. The top resonant structure isfixed to the intermediate dielectric layer, and includes a plurality of metal resonant structures arranged in an array. The plurality of metal resonant structures are fixed to the same end surface ofthe intermediate dielectric layer away from the bottom structure. A resonant cavity is disposed in each of the metal resonant structures. Each resonant cavity and the corresponding metal resonant structure are in a cross shape and have a coincident center. Both the metal film and the metal resonant structures are made of copper. The intermediate dielectric layer is made of a flexible PDMS material. Each resonant cavity is filled with a SrTiO3 material. The waver absorber realizes control of incident electromagnetic waves, tunes the wave absorbing frequency of the metamaterial in a large range, and overcomes the limitation of the passive tuning method of the wave absorbing property of the metamaterial.

The invention provides a tunable terahertz graphene metamaterial absorber. The tunable terahertz graphene metamaterial absorber comprises a four-layer structure laminated together: including a patterned graphene metamaterial top layer, a dielectric middle layer, a metal bottom layer and a substrate; the metal bottom layer is arranged on the substrate; the dielectric middle layer is arranged on themetal bottom layer; and the patterned graphene metamaterial top layer is arranged on the dielectric middle layer. Graphene is adopted to replace the conventional metal structure to establish the terahertz metamaterial absorber, and the Fermi energy of two graphene circular plates are tuned through static doping, so that the resonance characteristic of the two graphene circular plates and the nearfield coupling characteristic between the circular plates can be controlled, thereby realizing flexible control on the absorption strength, bandwidth and frequency of the absorber.

The invention discloses an adjustable terahertz metamaterial absorbing structure. The structure comprises a dielectric material substrate and metamaterial units distributed on the substrate, any one metamaterial unit comprises a pair of bottom metal layers correspondingly arranged and a super material array, the super material array is fixedly arranged on a flexible dielectric film, a cavity is formed between the flexible dielectric film and the bottom metal layers, the pressure of the cavity is regulated to achieve the regulation and control of the whole supper material absorbing structure for the terahertz absorbing. Through the whole formation of the supper material absorbing structure, special improvement for the key super material regulation and control principle (namely a corresponding) terahertz wave attraction control principle and the related corresponding components, the problems can be solved that the supper material is not convenient to prepare and not flexible in regulation compared to the prior art.

The invention discloses a multilayer annular terahertz metamaterial wave absorber comprising a bottom metal reflector plate and a multilayer structure above the metal reflector plate and characterizedin that the multilayer structure comprises three dielectric substrates and resonant units above respective dielectric substrates, wherein each resonant unit is coated with a high-resistance surface.The wave absorber has a good absorption effect on TE polarized waves and TM polarized waves. By coating the resonant unit above each dielectric substrate with the high-resistance surface, the wave absorber can achieve ultra-wideband wave absorption in the terahertz band. The multilayer annular terahertz metamaterial wave absorber avoids metal ohmic loss and heat loss by coating the resonant unitsabove the dielectric substrates with the high-resistance surfaces, so as to be suitable for operating in the light wave and terahertz band. The multilayer annular terahertz metamaterial wave absorberis simple in structure, flexible in design and powerful in functions.

The invention provides a terahertz ring couple device based on a photoselective regulation of metal-two-dimensional organic-inorganic hybrid perovskite material and a preparation method thereof, relates to the field of microelectronics and terahertz metamaterial functional devices, and solves the problems of complicated structure and preparation process, single function and narrow application range of the existing terahertz ring dipole metamaterials. The device comprises a substrate, two periodically arranged double-opening metal resonance ring structural units and two-dimensional organic-inorganic hybrid perovskite with different components respectively covered on the two double-opening metal resonance rings. The method comprises the steps: high resistance silicon is coated with photoresist, pre-baked, exposed, developed and fixed; metal is deposited; Parylene is deposited to form a mask structure; a perovskite solution is coated; annealing is performed; Parylene is deposited to forma mask structure; the perovskite solution is coated; and annealing is performed. The device has the advantages of simple application conditions, free switching of working modes, simple process and lowcost. The device is applied to the field of microelectronics and terahertz metamaterial functional devices.