141 results about "Fano resonance" patented technology

The invention provides an asymmetric Au particle array and FP cavity coupled refractive index sensor which comprises an insulation substrate, a metal film reflection layer, a transparent medium layer and a two-dimensional metal unit array, wherein at least one surface of the insulation substrate is polished; the metal film reflection layer is deposited on a polishing surface of the substrate; the transparent medium layer is deposited on the metal film reflection layer; the two-dimensional metal unit array is formed on the transparent medium layer, each metal unit in the two-dimensional metal unit array is an asymmetric unit, and is composed of two metal nano columns arranged along the surface of the substrate, and an F-P cavity loop is formed between the two metal nano columns of each metal unit and the metal film reflection layer just below the two metal nano columns. According to the asymmetric Au particle array and FP cavity coupled refractive index sensor, by combining an asymmetric Fano resonance effect and coupling an LSP mode and an FP cavity mode, the full width at half maximum of a resonance valley of the sensor can be reduced, and thus the performance of a local area surface plasma sensor is improved.

The invention relates to a sensor based on Fano resonance characteristics of a dielectric nanostructure. The sensor consists of a transparent substrate to light waves of a working wavelength range and asymmetrical dielectric nano bar pair arrays which are uniformly arranged on the transparent substrate. According to the low loss characteristics of dielectric materials and Fano resonance characteristics of the asymmetrical nano bar pair arrays, high Q-value resonance is generated. Meanwhile, an opening is introduced into a dielectric resonance unit, so that interaction between an electromagnetic field in a Fano resonance mode and ambient environment medium is effectively enhanced, and the sensitivity and quality factor of the sensor are improved. According to the sensor designed by the invention, the quality factor far exceeds that of a similar sensor based on the Fano resonance characteristics of a metal nanostructure, and the sensor disclosed by the invention has significant application prospects in the aspects of chemical and biological sensing, hazardous gas and pollutant monitoring.

The invention relates to a high-sensitivity micro-nano fiber compound type microcavity biochemical sensor. The biochemical sensor consists of a knot type micro-ring resonant cavity and a compound type microcavity, wherein the knot type micro-ring resonant cavity is made of micro-nano fibers, and the compound type microcavity consists of F-P microcavities formed in a manner that a femtosecond laser acts on two sides of the micro-ring resonant cavity. The manufacture method of the biochemical sensor comprises the following steps of: fusing a normal single mode fiber to prepare the micro-nano fiber, manufacturing two reflection mirrors in the micro-nano fiber by the femtosecond laser, and knotting between the two reflection mirrors, thus finally preparing a micro-nano fiber compound type microcavity formed by a micro-nano fiber F-P cavity and a knot type micro-nano fiber ring cavity. The micro-nano fiber compound type microcavity related to the invention has a huge change slope at a central wavelength position due to a Fano resonance spectral line, the tiny environmental parametric variation can be transformed into detectable intensity variation by a steep slope, and the sensitivity of the biochemical sensor can be greatly improved, so that the fast response speed and high-sensitivity micro-nano order biochemical measurement can be realized.

The invention provides a sensor based on gold nanorod dimer array Fano resonance characteristics. The sensor comprises a transparent substrate. The sensor is characterized in that two or more gold nanorod dimmers are arranged uniformly on the transparent substrate, and each gold nanorod dimer is formed by arranging two same gold nanorods in parallel. According to the sensor based on a gold nanorod dimer array structure of the invention, the Fano resonance characteristics of the array are utilized, and the sensing quality factor and the sensitivity are improved.

The invention provides a Fano resonance sensing apparatus based on an axisymmetric optical micro-cavity. The Fano resonance sensing apparatus comprises an axisymmetric optical micro-cavity and a coupled waveguide, wherein the axisymmetric optical micro-cavity has a columnar shape and comprises a straight cylinder type solid cylinder micro-cavity, a straight cylinder type hollow cylinder micro-cavity, a microbubble-like solid cylindrical micro-cavity, a microbubble-like hollow cylindrical micro-cavity, a micro ring cavity, a metal-coated cylindrical micro-cavity and the like, the material of the micro-cavity is silicon dioxide, a macromolecule polymer, an optic crystal, a semiconductor material and the like, and the coupled waveguide is optical fibers with a diameter of 0.5-1.5 [mu]m, a coupled prism having high refractive index, an on-chip integrated waveguide and the like. According to the present invention, the discrete high-order echo wall mode in the micro-cavity and the continuous background light are subjected to offset interference, such that the dynamically-changing Fano resonance spectrum can be stably and effectively produced.

The invention discloses a full-medium metasurface refractive index sensor based on polarization insensitive Fano resonance. The full-medium metasurface refractive index sensor is sequentially composedof a medium substrate and a medium metasurface microstructure unit array from bottom to top; the medium metasurface microstructure unit array is composed of a plurality of medium metasurface microstructure units; and each medium metasurface microstructure unit is composed of three V-shaped medium antennas, wherein the three V-shaped medium antennas are in mirror symmetry with respect to a plane (x=0) and have 120-degree rotational symmetry. The full-medium metasurface refractive index sensor is insensitive to the polarization state of any normal accident light, can generate Fano resonance, and has high-quality factors and high sensitivity, and the measurement needs in practical application are met.

The invention provides a terahertz metasurface biosensor based on Fano resonance, and a preparation method thereof. An ultrathin flexible polyimide film is used as a substrate of the sensor, and a periodically arranged metal asymmetric split ring structure is prepared on the upper surface of the sensor. When a line-bias terahertz wave of which the electric field vibration direction is parallel tothe structure opening direction is vertically incident, the Fano resonance effect can be excited, and a sharp asymmetric transmission spectrum line type is generated. Based on the metasurface design of Fano resonance, the ultrathin polyimide with low dielectric constant and low loss is used as the substrate, so that the detection sensitivity can be further improved, and the trace detection is realized. The terahertz metasurface biosensor has the advantages of low preparation cost, good ductility, small size, simple and convenient measurement and the like, and can be widely applied to terahertzwave spectrum biosensing.

The invention discloses a refractive index sensor based on double-Fano resonance. The sensor comprises a metal-insulator-metal waveguide; a metal partition in the waveguide takes the waveguide as thecenter, and the two sides of the waveguide are respectively provided with a rectangular cavity A and a rectangular cavity B; the rectangular cavity A is parallel to the waveguide, and the rectangularcavity B is vertical to the waveguide; the width of the metal-insulator-metal waveguide is w; the thickness of the metal partition is dm; the width and height of the rectangular cavity A are respectively L1 and H1; the distance between the rectangular cavity A and the waveguide is G1; the width and height of the rectangular cavity B are respectively L2 and H2; and the distance between the rectangular cavity B and the waveguide is G2. Optical waves can be coupled into the rectangular cavities at the two sides when being transmitted in a waveguide core; when a resonance condition is met, the Fano resonance is formed, and a corresponding resonance peak appears on the transmission spectrum of the Fano resonance. The Fano resonance is a weak coupling effect and is particularly sensitive to changes of structural parameters; the refractive index of filling mediums in the rectangular cavities at the two sides is changed to enable the Fano resonance peak to be deviated, so that the sensing of the refractive index of the medium is realized.

The invention discloses an asymmetric metamaterial capable of enhancing absorption by a fanno resonance on a near-infrared band. A resonant element of the metamaterial is removed from the center position thereof and rotated at an angle; and the transmission property of the resonant element on an electromagnetic wave is changed, so that an original dipole is changed into a quadrupole; and the resonance is enhanced. A sharp fanno resonance with a high-quality factor is formed on the near-infrared band, so that absorption on a near-infrared light is enhanced. The asymmetric metamaterial can be applied to the fields of a photocell, a slow light, sensing, nonlinearity, a photoswitch and the like.

The invention discloses an ultrahigh-precision wavelength resolver based on Fano resonance. A waveguide beam splitter is connected with an input end of a plurality of Fano filters; output ends of the Fano filters are connected to a signal processing module through the respective Fano filters; light to be detected is split into a plurality of bundles of light through the waveguide beam splitter; the plurality of bundles of light enter the Fano filters respectively, and are filtered, and then signals are output to a Ge-Si photoelectric detector; each Fano filter is internally provided with a TiN thermal electrode; and a Fano filtering spectral line is generated by adjusting the output of the Fano filters through heating the TiN thermal electrodes, so that an X-shaped frequency spectrum is formed. The ultrahigh-precision wavelength resolver based on the Fano resonance can realize ultrahigh-precision wavelength detection in an X frequency spectrum range; and the device is made of a common SIO silicon sheet, and has good CMOS (Complementary Metal Oxide Semiconductor) technical compatibility and can be integrated in a large scale.

The invention provides an LSPR (localized surface plasma resonance) sensing device. The LSPR sensing device comprises a substrate, wherein the substrate is provided with a metal layer, the metal layer is in an XI shape, and the size of XI is of a nano grade. The LSPR sensing device prepared through the method establishes an asymmetric XI nano gold structure, a specific peak in the LSPR phenomenon can be produced independently by the X and I structure; after the XI structure is formed by combining the X structure and I structure, the spectrum of the two structures can be collectively heterozygozed, and a multipeak phenomenon occurs; the XI structure can have a coupling effect, so that the heterozygosis peak is deviated; the DNA detection precision and sensitivity can be greatly improved; the noise caused by the nonuniform structure caused by a traditional method can be avoided, the situation that the peak is widened due to the disorder structure can be avoided, the heterozygosis of the specific spectrums of the two structures is resonated with Fano produced by the asymmetric structure, so that the LSPR sensor is more accurate in detection.

The invention discloses a double-layer coupling type Fano resonance sensor based on graphene and belongs to sensing devices in the technical field of infrared, and the surface plasma characteristics of the graphene are utilized; the sensing device is in a three-dimensional periodic structure and structurally comprises a silicon substrate layer, a silicon dioxide substrate layer, a graphene disk middle layer, a silicon dioxide isolation layer and a graphene disk top layer; the transmittance spectrum of the double-layer coupling type Fano resonance sensor based on the graphene in the middle-infrared band is computed and simulated with a finite element method, the sensor structure is optimized, high-performance Fano resonance can be stimulated in the middle-infrared band, the resonance curveis sensitive to the change of substance refractive indexes, and the detection functions on gas and liquid in the middle-infrared band are provided. The double-layer coupling type Fano resonance sensorbased on the graphene is simple, compact and reasonable in structure and convenient to process.

The invention discloses a device and a method for measuring the detection limit of a Fano resonance sensor. The device comprises a laser, a collimating objective lens, a polarizer, a sensor, a polarization detector, a focusing objective lens and a spectrometer. The sensor comprises a coupling prism, an Au film, a Cytop film, a TiO2 film, and a sensing medium. Compared with other polarization measuring devices, the device adopts the coupling of a surface plasma polariton mode and a planar waveguide mode formed in a multilayer medium to generate the Fano resonance, so that the detection limit ofthe plasma sensor is further improved; the structure is simpler by replacing original two polarizers with one polarizer; more importantly, the polarization effect of a reflected light is analyzed byadopting the method for measuring the Fano resonance sensor, and the traditional reflected light intensity detection is replaced with a polarization function, so that the detection limit of the Fano resonance sensor is remarkably improved.

An MIM type nanorod dimer capable of realizing triple Fano resonance adopts a metal-insulator-metal (MIM) type nanorod dimer structure, and realizes triple Fano resonance through exciting magnetic surface plasmons (MSPs) to obtain triple Fano resonance; and two MIM type nanorods with completely same dimensions are arranged in a side-to-side manner in the xy plane, the material of two metal layers is gold (Au), the thicknesses of the two metal layers are same, and a dielectric layer between the two metal layers is silica (SiO2). The MIM type nanorod dimer structure is simple, is easy to prepare, can realizes triple Fano resonance, and can be used to design and produce multi-wavelength optoelectronic devices; and when the MIM type nanorod dimer structure is used in biochemical sensing, the low loss characteristic of Fano resonance and the common sensing using multiple wavelengths with different sensitivities make the sensing sensitivity and the sensing accuracy be improved.

The invention discloses a multi-wavelength adjustable nanosensor capable of realizing Fano resonance. The multi-wavelength adjustable nanosensor comprises a substrate and a nanostructure arranged on the substrate, wherein the nanostructure comprises a cavity, an input waveguide, an output waveguide, double nanorings located in the cavity and a nanostrip located in the center of the double nanorings, wherein the input waveguide and the output waveguide are located on two sides of the cavity and oppositely arranged; the double nanorings comprise an outer nanoring and an inner nanoring which are distributed concentrically, and each of the outer nanoring and an inner nanoring comprises at least two symmetrically distributed split ports; the angle of a longitudinal direction, relative to an electromagnetic wave signal input/output direction, of any edge of the nanostrip is adjustable, so that the sensor realizing different transmissivity is obtained. The multi-wavelength adjustable nanosensor capable of realizing Fano resonance is designed on the basis of the principle of a metal surface plasmon effect, is simple in structure, convenient to manufacture, high in sensitivity and wide in adjusting range and is applicable to detection and monitoring in the fields of chemistry, medical treatment, environment and the like.

The invention provides an adjustable Fano resonance integrated device. The device comprises a substrate, and further comprises a micro-ring waveguide and a coupling straight waveguide which are integrated on the substrate, wherein grating reflectors which are arranged on a top surface of a coupling straight waveguide and are positioned at two ends of a coupling region, and a micro heater which isarranged above the micro-ring waveguide. The invention further provides a manufacturing method of the device, a grating is etched on a top surface of the coupling waveguide to form the partial reflectors, a Fabry-Perot resonant cavity is formed between the two partial reflectors and acts with the micro-ring resonant cavity, namely, the micro-ring resonant mode is coupled with the Fabry-Perot resonant mode, and a Fabry-Perot resonant spectral line is formed at an output end. The resonance wavelength of the micro-ring is thermally adjusted by externally applying a voltage to the micro heater, sothe resonance wavelength and slope of the Fano resonant spectral line can be flexibly adjusted. The device can stably generate high-sharpness fano resonance spectral lines, can be used for large-scale tape-out production of a general semiconductor micromachining platform, and has a high application prospect.

The invention is a method of Fano resonance microwave spectroscopy of high absorption matter. The method comprises: embedding a magnetic-dipolar-mode (MDM) ferrite disk in the microwave cavity, loading a sample of the high absorption matter in the microwave cavity, using a bias magnetic field to tune the MDM resonance frequency of the ferrite disk to the resonance frequency of the cavity; and observing the symmetric Lorentz-like lineshape of the resonance peaks that are obtained.

The invention provides a sensor with a three-aperture structure. An asymmetric response spectrum line shape with steep is produced by using mutual effect of explicit mode resonance and implicit mode resonance of three dipole resonance units of the structure, thereby designing the sensor with the three-aperture structure possessing a Fano resonance phenomenon transmission spectrum. Under the same switch contrast, the wavelength shift or interval reuiqred by the asymmetric response spectrum line shape is less than the spectral width of the symmetric Lorenz-like line shape obtained by a single resonant cavity, and the wavelength resolution of a wave-division multiplexer and the sensitivity of the biosensor can be increased. The red shifts in different degrees of the Fano peak occur in the transmission spectrum by controlling geometric parameters of the structure, thereby realizing the tuning of the Fano resonance; the resonant frequency band change in the sensor can be realized by changing the scale of the structure parameters in equal proportion by adopting scaling theorem, namely, the working band is not limited to the THz band; the sensor can be used for the wave-division multiplexer, an optical switch, the biosensor and like fields.

The invention relates to a device and a method for realizing electric regulation and control of Fano resonance based on asymmetric split-ring resonators. A variable capacitance diode is embedded in the middle of each of the two split-ring resonators, and meanwhile, feeding wires are added to the upper side and lower side of the two split-ring resonators respectively; the feeding wires are connected with an external power supply and adjust the voltage at the two ends of the variable capacitance diode; and inductors are added between the feeding wires and the split-ring resonators respectively to isolate the influence of the feeding wires on the electromagnetic response of the metamaterial structure. The working state of the variable capacitance diode is adjusted by using the feed voltage, and then the working frequencies of the two split-ring resonators are adjusted, so that dynamic modulation of the Fano resonance transmission spectral line is realized. The two split-ring resonators are different in size, the asymmetric structure is utilized to excite a magnetic four-level mode, and destructive interference occurs between the magnetic four-level mode and a magnetic dipole mode excited by an electric field, so that the transmission spectral line shows a Fano resonance line type.

A terahertz meta-structure device with strong Fano resonance is designed, and the intensity of the terahertz meta-structure device can be modulated by low-power continuous light. The device is simplein structure, a thin silicon substrate is obtained through the technology of etching high-resistance silicon and SOI(silicon on an insulating substrate) on the back side, the used substrate serves asa photoactive layer, extra photoactive materials are not needed, the overall preparation process is matched with an existing processing technology, and the device can be processed in a process mode, is not influenced by the technology of operators and is high in yield. Because carriers in the silicon substrate can be excited by photons with the forbidden bandwidth higher than that of the silicon substrate, the Fano resonance intensity can be modulated by low-power continuous light, an expensive femtosecond pulse source is not needed, 90% of modulation depth and 0.6-0.85 of modulation amplitudecan be easily obtained, the modulation amplitude is 2-3 times of that reported in the past, and the modulation efficiency is greatly improved. The terahertz meta-structure device opens up a new way for biochemical sensors with higher sensitivity pursuit.