48 results about "Nonlinear optics" patented technology

The invention discloses a multi-mode nonlinear optical microscopic imaging device and system, and the device achieves the two-photon and three-photon excitation imaging of a sample through an integrated light source module, a dispersion compensation module, a scanning light path module, a fluorescence obtaining module, a synchronous control module and a signal processing module. Fluorescence intensity imaging and fluorescence lifetime imaging can be supported at the same time; wherein the scanning light path module is driven by the random mask to realize sparse scanning, so that scanning point locations are effectively reduced, and the exciting light dosage is reduced; the synchronous control module performs time window screening and processing on the fluorescence signal based on the pulse synchronous signal and the position code, so that the signal acquisition efficiency is improved; the signal processing module adopts an FPGA (Field Programmable Gate Array) to carry out real-time image reconstruction and life calculation, so that the imaging speed and quality are ensured; and the master control PC can also perform high-fidelity reconstruction on the sparse sampling image through a deep learning model, so that high-speed, low-light-dose and high-resolution nonlinear fluorescence intensity and life imaging is realized.

The invention discloses a self-adaptive spatial transformation network for cross-medium optical distortion, and solves the problem that the existing spatial transformation network is difficult to consider both global transformation and local nonlinear optical distortion. The network is integrated in a target detection model, and the method comprises the steps that firstly, a parameter prediction network synchronously outputs affine transformation parameters and a water surface fluctuation physical parameter diagram; then, the local distortion grid generation network generates a distortion sampling grid based on the parameter diagram and a predefined water surface fluctuation physical model; meanwhile, the grid generator generates an affine sampling grid according to the affine transformation parameters; then, a grid fusion device fuses the two grids to generate a final sampling grid; and finally, the sampler samples the input image or the feature map according to the final sampling grid to obtain an output image or a feature map. Through a space transformation mechanism guided by physical prior, optical distortion caused by water surface fluctuation can be effectively relieved, and the accuracy and robustness of a target detection model in a cross-medium underwater scene are remarkably improved.

The invention discloses a reflective pumping detection nondestructive testing device and method capable of saturatively absorbing uniformity in a mirror surface. The device is based on a wavelength degeneracy pumping-detection principle, and comprises a femtosecond laser source, a beam splitter, an optical delay line, a double-frequency optical chopper, a two-dimensional precision translation stage, a coaxial focusing system, a spatial filtering diaphragm arranged in a reflection light path, a photoelectric detector, a lock-in amplifier and a signal processing unit. According to the method, different point positions of a sample are accurately positioned through a two-dimensional translation stage, a nonlinear differential reflectance dynamic curve of each point is measured under low power, the maximum differential reflectance and the carrier lifetime are extracted as characteristic parameters, the spatial relative standard deviation of the characteristic parameters is calculated, and lossless and quantitative in-plane uniformity evaluation is realized. According to the method, the interference of the pump light is effectively filtered through the space filtering diaphragm, the signal-to-noise ratio is remarkably improved in combination with the phase-locked amplification technology, and the problem that the nonlinear optical performance uniformity of the saturable absorber mirror cannot be quantitatively evaluated through a traditional method is solved.

The invention discloses a dual-wavelength frequency doubling regulation and control method based on a PPLN waveguide, and relates to the technical field of nonlinear optics. The method comprises the following steps: constructing a PPLN waveguide model, and determining a fundamental frequency light mode and a frequency doubling light mode; calculating effective refractive indexes of the fundamental frequency light and the frequency doubling light at respective wavelengths; the polarization period is calculated according to the effective refractive index, any target polarization period is fixed, the target polarization period is configured to correspond to two different working wavelengths at the same time, and therefore dual-wavelength frequency doubling light with a specific wave crest interval is generated at the output end of the waveguide; the wave crest interval is regulated and controlled by selecting different polarization periods; according to the invention, dynamic control of dual-wavelength frequency multiplication output is realized by changing the size of a polarization period; the single waveguide can complete various optical function design ideas, and has certain value for research in related fields such as multi-wavelength lasers and wavelength multiplexing communication.

The application discloses an SBS phase conjugation mirror capable of displaying a sound wave field in real time, and belongs to the technical field of nonlinear optics.The application comprises the following steps: pump light passes through a half-wave plate and a polarization beam splitter, passes through an optical isolator, changes a polarization state through a quarter-wave plate, is focused through a focusing lens, and then enters an SBS medium pool, stimulated Brillouin scattering occurs, a periodic density modulation is formed in the medium, and an equivalent acousto-optic grating structure is generated.Through introducing an independent probe light beam, the probe light enters the SBS medium pool at an incident angle satisfying the Bragg diffraction condition, and the probe light will be diffracted on the acousto-optic grating formed by the sound wave field.The intensity of the diffracted light changes with the intensity of the sound wave field, so that the real-time measurement of the sound wave field waveform and the life parameter in the SBS process can be realized by detecting the change of the diffracted light intensity with time.

The utility model discloses a metasurface unit structure and a metasurface formed by the metasurface unit structure, and belongs to the technical field of nonlinear optics. The metasurface unit structure comprises a substrate layer and a dielectric layer which are arranged from bottom to top, wherein a convex groove or a concave groove is formed in the dielectric layer. The sections of the substrate layer and the dielectric layer are square, and the sizes are nanoscale; the substrate layer is made of SiO2, and the dielectric layer is made of DAST crystals. The metasurface is formed by periodically arranging a plurality of metasurface unit structures. According to the utility model, the convex or concave grooved structure, the substrate layer with low refractive index, the DAST dielectric layer which has a higher damage threshold and is easy to process and the like are introduced, so that the loss can be reduced, the asymmetry degree can be conveniently adjusted by changing the grooved structure, the quality factor Q can be changed, the local electric field distribution can be optimized, and different application requirements can be met.

A terahertz wave generating device includes: a pump light source configured to generate pump light; a periodically poled element as a nonlinear optical element having a periodic structure in which a polarization or a crystal orientation is inverted at a certain inversion period; and a rotation stage configured to rotatably support the periodically poled element. The terahertz wave generating device causes the pump light to enter the periodically poled element to generate signal light that is a terahertz wave, and rotates the periodically poled element to change a wavelength of the signal light. The periodically poled element has an incident end face through which the pump light enters and an output end face through which the pump light exits. A rotation axis of the periodically poled element is closer to the incident end face than to the output end face.

The application discloses a kind of based on non-interacting polarization multiplexing multi-path pulse compression device and method, it is related to ultrafast laser technology and nonlinear optics field, device includes: first polarization beam splitter, Faraday rotator, second polarization beam splitter and dispersion compensation module, dispersion compensation module is used to make pulse multiple pass through same dispersion compensation element and form return pulse, return pulse is converted into polarization state orthogonal with incident state by Faraday rotator after by first polarization beam splitter output. By Faraday non-interacting coaxial architecture, pulse keeps high-efficiency polarization matching, reduces astigmatism, spatial chirp and energy loss caused by off-axis folding, and when target dispersion amount is certain, optical envelope volume is reduced, and element light aperture requirement is reduced;While pulse compression and reverse light isolation are integrated in the same magneto-optical component, reduce the number of discrete components, improve system compactness and stability.

The present application belongs to the field of ultrafast laser and nonlinear optics, and particularly relates to a near-infrared few-cycle pulse generation system and method based on high-pressure nonlinear enhancement. The method fills inert gas into a hollow-core anti-resonant optical fiber and adjusts the gas pressure to the high-pressure interval of 20 bar-90 bar, enhances the nonlinear coefficient of the gas to realize the dispersion and nonlinear dynamic balance of the pulse in the waveguide, thereby compensating for the insufficient peak power of the low-energy pump pulse. The pulse feedback module collects the output time-domain intensity waveform and extracts the main peak energy proportion and the splitting factor as feedback indexes. The control module diagnoses the offset state of the self-compression focal point relative to the truncated end face according to the feedback indexes, controls the small-step pressure regulation of the gas pressure regulation module to anchor the focal point on the truncated end face, and directly outputs high-quality and high-coherence near-infrared few-cycle pulses without external dispersion compensation devices.

A kind of full-automatic intelligent, multi-functional high-order nonlinear fluorescence kinetics test method and device, it relates to nonlinear optics and nanophotonics field.The optical testing device consisting of excitation light generation module, automatic power regulation module, excitation light modulation module, sample scanning module, data acquisition and analysis module and intelligent control module is built, under the excitation of incident laser, based on the overall coordination of intelligent control module, drive the rest each module to complete the dynamic response test of nonlinear fluorescence sample, realize full-automatic intelligent, multi-functional, high-precision, simple, efficient, low cost, universal fluorescence kinetics test analysis.The problem of traditional manual time-consuming and low test accuracy is solved.In addition, the multi-functional integration of fluorescence response curve, fluorescence rise time, fluorescence lifetime and fluorescence imaging effectively improves the test efficiency and application scenario, greatly reduces the system cost.

The invention relates to the technical field of semiconductor measurement, in particular to a film layer measuring device and method.The film layer measuring method comprises the steps that a to-be-measured position on the upper surface of a to-be-measured film layer is irradiated with pump light, and the pump light initiates second-order nonlinear optical coefficient change of the to-be-measured film layer and forms local disturbance; the local disturbance is propagated back and forth between the upper surface and the lower surface of the to-be-detected film layer; probe light is adopted to irradiate the to-be-detected position, the probe light generates frequency multiplication signal light based on the second-order nonlinear optical effect, and when the local disturbance is transmitted to the upper surface, the light intensity of the frequency multiplication signal light reaches a peak value; and receiving the frequency-doubled signal light, and obtaining the thickness of the to-be-measured film layer based on a time interval between two adjacent light intensity peak values of the frequency-doubled signal light. The invention is at least beneficial to improving the film thickness measurement precision.

The invention provides a nonlinear optical neural network system and a nonlinear optical calculation method, and the system comprises an optical feedback structure which is used for forming a circulating light path so as to enable a light beam to be circularly transmitted in the system; the input coupling assembly and the output coupling assembly are respectively used for coupling an input light beam to the circulating light path and coupling a part of light beam from the circulating light path as an output light beam; the spatial light modulation device is used for regulating and controlling at least one of the amplitude and the phase of the light beam input by the spatial light modulation device; the diffraction regulation and control assembly is used for executing multi-layer diffraction operation and regulation and control on the light beams input by the diffraction regulation and control assembly; wherein the spatial light modulation device and the diffraction regulation and control assembly are both arranged in the circulation light path, and the configuration mode of the spatial light modulation device and the diffraction regulation and control assembly enables a light beam to sequentially pass through the spatial light modulation device and the diffraction regulation and control assembly in each circulation, and the light beam reaches the output coupling assembly after passing through the diffraction regulation and control assembly.

The present invention generally relates to improved methods for characterizing the cell wall complex composition of a bacterial specimen via differential transport kinetics of a small molecule. The present invention also relates to improved and automated methods for Gram differentiation of a bacterial specimen using nonlinear optical techniques.

The invention provides a nonlinear data generation and processing method based on light quantum and a light quantum computer, and the method comprises the steps: obtaining a nonlinear function and attribute information of a nonlinear layer; according to the frequency spectrum number and the attribute information of the nonlinear function, constructing an initial light quantum circuit; measuring the initial light quantum circuit, and determining a target function corresponding to the initial light quantum circuit according to a measurement result; loss information of the target function is determined, whether the initial light quantum circuit is applied or not is determined according to the loss information, and if yes, the initial light quantum circuit serves as a target light quantum circuit; and performing operation on input data of the nonlinear layer based on the target light quantum circuit. According to the method, the low-energy-consumption characteristic of photon calculation, the nonlinear characteristic of light quantum calculation and the general programmable capability of electronic calculation can be fused, and high-energy-efficiency calculation can be carried out on input data of a nonlinear layer. In addition, the method also has the advantages that the complexity of a quantum circuit is smaller, and the participation of a nonlinear optical device is not needed.

The invention discloses a cylindrical light-transmitting frequency doubling device for generating tunable yellow light and a laser device, and belongs to the nonlinear optical technology, the cylindrical light-transmitting frequency doubling device comprises a rubidium titanyl phosphate crystal, the rubidium titanyl phosphate crystal is processed into a cylinder along the Y-axis direction, and the cylindrical surface of the cylinder is plated with a dual-waveband antireflection film of 1140-1180 nm and a dual-waveband antireflection film of 570-590 nm. By means of the cylindrical surface light-passing frequency doubling device, the comprehensive performance of the yellow light frequency doubling device can be improved.

An optical surface analysis device (1) allows for the advantageous measurement, at the same location on a sample surface, of a nonlinear second harmonic generation (SHG) signal and a linear absorption signal in reflectivity, and their correlation to obtain information about the sample surface microstructure. The optical device was designed to integrate nonlinear reflectometry for SHG signal detection, visible reflection-absorption spectroscopy (Vis-RAS), and a visual control device for the sample surface using bright-field microscopy (CF), while maintaining the device's compact size. Abstract figure: Figure 1

A laser system generates laser pulses having a determined carrier-envelope-offset, CEO. The laser system includes a Cr-doped II-VI based laser oscillator system having a resonator cavity, which emits laser pulses having a peak power of at least 0.75 MW. The laser system further includes a nonlinear optical element for spectrally broadening at least a part of the emitted laser pulses irradiated onto the nonlinear optical element to provide the laser pulses with octave-spanning spectral components, and a frequency-doubling element for generating second harmonic spectral components of at least a part of the octave-spanning spectral components. In addition, the laser system includes an f-2f-interferometry device for generating a beating signal of at least a part of the overlapping spectral components exiting the frequency-doubling element and interfering with each other at the f-2f-interferomtry device and for determining and / or controlling the CEO of the emitted laser pulses based on the beating signal.

A decrease in accuracy caused by influence of noise light is suppressed.A spectroscopic device (1) includes a light source (2), a quantum optical system (4), a detection unit (6) that detects a light intensity of light output from the quantum optical system (4), and an analysis device (8), the quantum optical system (4) including one or more nonlinear optical elements (12) that generates a photon pair of idler light and signal light from the pump light in an entangled photon pair generation process, and a sample placement tool (35) that places a sample (SP) on an optical path of the idler light. The quantum optical system (4) is configured to emit first and second signal lights (s1, s2) along different optical paths, the detection unit (6) includes a beam splitter (40) that receives the first and second signal lights (s1, s2) from the quantum optical system (4), and detects a light intensity of each of two lights emitted from the beam splitter (40), and the analysis device (8) acquires an interferogram from the two lights detected by the detection unit (6).

This invention belongs to the field of nonlinear optics and extreme ultraviolet coherent light source technology, specifically relating to a method for generating a quasi-monochromatic circularly polarized extreme ultraviolet light source. The method involves: constructing a reverse-rotating bicolor circularly polarized laser field as the driving light source; this reverse-rotating bicolor circularly polarized laser field is a superimposed field of reverse-rotating circular polarization composed of a fundamental frequency light field and a second harmonic light field; in a vacuum environment, the reverse-rotating bicolor circularly polarized laser field is coincident in time and space and focused into a medium to generate high-order harmonic radiation; by adjusting the relative intensity of the fundamental frequency light field and the second harmonic light field, a quasi-monochromatic circularly polarized extreme ultraviolet light source is generated; the medium is an atomic, ionic, or unarranged molecular system. The method of this invention is simple to implement experimentally, and the resulting circularly polarized extreme ultraviolet light source has high monochromaticity and high polarization purity, solving the problem of previous methods for generating quasi-monochromatic extreme ultraviolet light sources that relied on complex media and could not simultaneously achieve monochromaticity and circular polarization state.

The invention belongs to the field of integrated optics, optical communication and nonlinear optics, and particularly discloses an optical device based on a double-resonance PPLN. Through the two cascaded FP cavities, the resonant FP inner cavity only resonates frequency doubling light to improve the difference frequency efficiency, and the resonant FP outer cavity only resonates pump light to improve the frequency doubling efficiency; in the frequency doubling process, the pump light and the frequency doubling light are respectively enhanced by resonance due to the outer cavity and the inner cavity; in the difference frequency process, the frequency doubling light is enhanced by resonance, so that the nonlinear frequency mixing efficiency can be greatly enhanced through triple resonance enhancement in the optical parametric amplification process. Signal light in the structure does not resonate in the inner cavity and the outer cavity, so that wavelength transparent operation can be realized in a large range. The optical parametric amplification or wavelength conversion function is realized based on the frequency doubling and difference frequency principle, the signal light is not limited by the FSR of the resonant cavity, broadband operation can be realized, and the realization of high-speed all-optical signal processing is expected to be promoted.

The invention relates to a polaroid and a display device. The polaroid comprises a base layer, a polarization layer and a light modulation layer. The polarization layer is arranged on one side of the base layer; the light modulation layer is arranged on one side of the polarization layer away from the base layer; wherein the material of the light modulation layer comprises a nonlinear material, and the light modulation layer is configured to dynamically regulate and control the polarization state of polarized light incident to the light modulation layer; according to the polaroid, the light modulation layer is arranged on the polarization layer, the light modulation layer contains the nonlinear material and has the nonlinear optical characteristic, and therefore the light modulation layer can respond to changes of external conditions, dynamic regulation and control over the polarization state of polarized light are achieved, and the requirements of a self-adaptive optical system, high-dynamic-contrast display and the like are met; and meanwhile, the device has the characteristics of simple structure and high response speed.

The invention discloses a method for predicting Se vacancy infrared nonlinear optical response in few-layer PtSe2, and the method comprises the following steps: S1, constructing a few-layer PtSe2 model, and carrying out the in-plane expansion; s2, introducing Se vacancy into the model after cell expansion; s3, performing structural relaxation on the Se-containing vacancy structure until atomic force and energy converge; s4, calculating an electron energy band structure of the relaxed structure based on a density functional theory; s5, constructing a maximum localization Wannier function, and fitting the electron energy band structure obtained in the step S4; s6, calculating an in-plane nonlinear displacement current component of the few-layer PtSe2 in an infrared band; and S7, analyzing the change of the nonlinear displacement current component obtained in the step S6 in the infrared band, and predicting the influence of Se vacancy on the infrared nonlinear optical property. The infrared nonlinear optical property prediction method provided by the invention is low in cost and high in precision.

The utility model discloses medical imaging equipment based on terahertz, and the imaging equipment comprises a terahertz radiation module which generates broadband high-intensity terahertz waves based on the nonlinear optical effect of a nanometer antenna array, and is used for irradiating a detection body within the range of the terahertz waves; the terahertz wave band composite FSS band-pass filter is arranged between the terahertz radiation module and the detection body and is used for gating terahertz waves; the detection module is used for receiving terahertz waves carrying optical information of a detection body; and the image processing module is electrically connected with the detection module and is used for carrying out digital image processing on the terahertz waves carrying the optical information of the detection body to obtain a terahertz medical image of the detection body. Therefore, three-dimensional real-time non-destructive living medical imaging and objective case detection can be realized.

A non-linear optical metasurface of a planar structure and a preparation method thereof belong to the technical field of metasurfaces, the non-linear optical metasurface comprises a substrate layer, a non-linear material layer and a protective layer, the non-linear material layer is located on the surface of the substrate layer, and the protective layer is located on the surface of the non-linear material layer; the non-linear material layer comprises crystalline-state superstructure units and amorphous-state regions which are periodically arranged in a sub-wavelength manner; the sub-wavelength periodically arranged crystalline state superstructure units are of a cylinder structure in the geometrical shape, and the arrangement mode is a square lattice, a hexagonal lattice or a triangular lattice. According to the invention, the interaction between light and a nonlinear material can be enhanced, and the third harmonic conversion efficiency of a specific mid-infrared band is enhanced; meanwhile, the surface topography of the metasurface fluctuates slightly and is far smaller than the working wavelength, the metasurface can be regarded as a flat surface on the optical scale, and the metasurface can be easily integrated with an on-chip nonlinear optical system; in addition, one-step preparation can be achieved, developing and etching are not needed, the machining speed is high, cost is low, and the requirement for the machining environment is simple.

A method of mode-locking utilizes passive frequency modulation of frequency comb induced stimulated Brillouin scattering resonance (SBSR) in a waveguide. It is discovered by the inventor that the SBSR effect creates a feedback control in forming down-chirped sech2-shaped bright or dark solitons in waveguides. These genuine solitons do not suffer from Cherenkov (or dispersive) radiation in transmission and adapt to different waveguides if peak intensity requirements are met. The mode-locking of an adaptive soliton laser with all passive fibers having the same type of dispersion is self-started and sustained by SBSR effect. This nonlinear optical effect suppresses Kelly-sidebands and broadens the spectrum for chirped femtosecond soliton generation. Adaptive soliton lasers of normal dispersion are capable of generating high energy solitons.

The application relates to the field of coordination chemistry and provides a lead-based perovskite material, a preparation method and application, the chemical formula of the lead-based perovskite material is (C 10 H 11 N3)PbBr4, the lead-based perovskite material belongs to a monoclinic system, and the preparation method comprises the following steps: placing bis (4-pyridine) amine and lead bromide in a round-bottom flask, then adding hydrobromic acid, and then reacting under an oil bath at 373-393 K for 3 h; after standing, filtering, and cooling to room temperature, the lead-based perovskite material is obtained. The lead-based perovskite material with a second-order nonlinear optical effect, the preparation method and application, the lead-based perovskite material preparation operation is simple, energy consumption is low, easy to realize, reaction time is short, and the requirements for reaction and purity are low; and the lead-based perovskite material has a second-order nonlinear optical effect.

The application relates to the field of nonlinear optics and discloses a nonlinear transmission matrix measuring device and method, which comprise a first laser, a first half-wave plate, a first convex lens, a second convex lens, a first reflector, a second laser, a second half-wave plate, a third convex lens, a fourth convex lens, a spatial light modulator, a second reflector, a first dichroic mirror, a second dichroic mirror, an objective lens, a second-order nonlinear scattering medium, a third reflector, a filter, a fifth convex lens and a CCD camera. The application generalizes the traditional transmission matrix method from linear optics to the field of nonlinear optics, realizes accurate solving and measuring of a transmission matrix between a fundamental frequency light field incident into a scattering medium and an emitted nonlinear scattering light field, and realizes arbitrary regulation and control of nonlinear harmonics through the nonlinear transmission matrix. Compared with a feedback algorithm, the nonlinear transmission matrix method can reduce time consumption and realize quick switching of different regulation and control requirements.

The present application belongs to the field of ultrafast laser and nonlinear optics, and particularly relates to a near-infrared few-cycle pulse generation system and method based on high-pressure nonlinear enhancement. The method fills inert gas into a hollow-core anti-resonant optical fiber and adjusts the gas pressure to the high-pressure interval of 20 bar-90 bar, enhances the nonlinear coefficient of the gas to realize the dispersion and nonlinear dynamic balance of the pulse in the waveguide, thereby compensating for the insufficient peak power of the low-energy pump pulse. The pulse feedback module collects the output time-domain intensity waveform and extracts the main peak energy proportion and the splitting factor as feedback indexes. The control module diagnoses the offset state of the self-compression focal point relative to the truncated end face according to the feedback indexes, controls the small-step pressure regulation of the gas pressure regulation module to anchor the focal point on the truncated end face, and directly outputs high-quality and high-coherence near-infrared few-cycle pulses without external dispersion compensation devices.

The application relates to the technical field of nonlinear optics, and discloses a second-harmonic signal reconstruction method and product based on amplitude-phase joint filtering, which comprises the following steps: performing second-harmonic polarization imaging on a sample by using a microscopic imaging system to obtain a plurality of second-harmonic intensity images; constructing a three-dimensional image stack based on the plurality of second-harmonic intensity images; performing Fourier transform on the three-dimensional image stack along a third dimension to obtain a target frequency domain data set; performing joint filtering processing on the amplitude and the phase in the target frequency domain data set, and reconstructing to obtain a plurality of initial time domain second-harmonic intensity images after denoising; and performing adaptive threshold denoising processing on the plurality of initial time domain second-harmonic intensity images to obtain a plurality of target time domain second-harmonic intensity images of the sample. Therefore, by implementing the application, the amplitude and the phase information are jointly processed, the target signal can be more accurately restored, and the imaging quality is improved.

The application discloses a kind of big energy stimulated raman laser based on batten structure, belong to laser technology and nonlinear optics field.The laser includes pump source, shaping optical system, batten laser crystal, Q device, resonant cavity and amplification structure.The laser uses batten gain medium and raman crystal, realizes high-efficiency 1 μm pulse laser output by partial end face pumping and polarization double-pass amplification technology;Further utilize external cavity raman resonant cavity to generate stable stimulated raman seed light, and pass through multi-mirror regulation light path, so that seed light and pump light are in batten raman amplification crystal space synchronization, realize high-efficiency stimulated raman amplification.The application effectively solves the problem of poor heat dissipation and significant thermal effect of traditional rod structure, has the advantages of high heat dissipation efficiency, good beam quality, large output energy, strong stability, is suitable for atmospheric laser radar detection, photoelectric countermeasure, spectrum detection, medical treatment and industrial processing and other fields.