262 results about "Raman scattering" patented technology

The invention relates to the technical field of spectrum detection, and particularly discloses a preparation method of a microstructure enhanced optical fiber and a Raman spectrometer light collection system thereof, the system comprises: a light source assembly for generating laser and performing collimation treatment on the laser to make the collimated laser irradiate a to-be-detected sample; the detection area assembly is used for placing a to-be-detected sample and positioning the to-be-detected sample; the collection assembly is used for collecting Raman scattering light generated by the sample to be detected under laser irradiation based on the microstructure enhanced optical fiber, and the optical fiber end face of the microstructure enhanced optical fiber is provided with a micro-nano structure; the geometric parameters of the micro-nano structure are determined by global optimization by using the genetic algorithm to maximize the coupling efficiency of the unpolarized diffused light in a preset wavelength range as an optimization target; and the control analysis assembly is used for carrying out signal acquisition from the collected Raman scattering light and identifying component information corresponding to the to-be-detected sample through a preset component identification model based on a signal acquisition result.

The invention belongs to the technical field of communication, and provides a communication optical cable state real-time online monitoring method and system. Calculating the vibration displacement of the optical cable based on the original back scattering light signal, and calculating the real strain and temperature of the optical cable based on a Brillouin scattering signal and a Raman scattering signal obtained by separating the original back scattering light signal; carrying out filtering, denoising, normalization and time-space alignment processing on the vibration displacement of the optical cable, the real strain of the optical cable and the temperature, and binding the vibration displacement and the real strain with the obtained geographic coordinates; obtaining time domain, frequency domain and time-frequency domain features based on the preprocessed vibration displacement, real strain and temperature data to form a multi-dimensional feature vector, inputting the feature vector into a pre-trained event recognition model, and outputting an abnormal event classification result; and judging and triggering abnormal event early warning based on an output result of the event recognition model and a preset dynamic threshold.

The invention belongs to the technical field of gas analysis, and relates to a surface-enhanced Raman scattering flexible substrate material as well as a preparation method and application thereof. The surface-enhanced Raman scattering flexible substrate material comprises a three-dimensional network structure and silver nanoparticles, the three-dimensional network structure is composed of hydroxypropyl methyl cellulose nanofibers, the silver nanoparticles are wrapped in the hydroxypropyl methyl cellulose nanofibers, and the silver nanoparticles are of a polyhedral structure. The surface-enhanced Raman scattering flexible substrate material is used for detecting thiol compounds in a solution, and the detection limit can reach 10 <-19 > M level; after the surface of the silver nanoparticle is modified with the probe, the material can detect trace substances in exhaled air. In addition, after the material is stored for 6 months at room temperature, the SERS signal intensity attenuation is less than or equal to 4%, and the relative standard deviation detected by 20 random sites is only 4.04%.

The invention relates to the technical field of subkeys and communication, discloses a quantum key distribution and wavelength division multiplexing cooperative scheduling method for a metropolitan optical network, and aims to solve the problems of insufficient key rate and classic service quality reduction caused by mutual interference of quantum signals and classic services in a shared optical fiber. The method comprises the following steps: modeling Raman scattering and crosstalk noise between quantum and classical signals; constructing a joint optimization model which aims at minimizing classic service degradation and ensures that the quantum key rate is not lower than a threshold; solving wavelength, power and routing allocation by combining mixed integer programming and an intelligent algorithm; the key generation window and the reconfiguration wavelength are dynamically scheduled based on the service load prediction; according to the technical scheme, dual optimization of safety performance and network resource utilization efficiency can be realized.

The invention discloses a spectral analysis device and method for gas Raman scattering of a hollow-core optical fiber, and belongs to the technical field of gas analysis sensing. The spectrum analysis device comprises a laser, a light beam coupling device, a hollow-core optical fiber gas sample chamber, a collecting device and a spectrograph which are sequentially arranged along a light path, the light beam coupling device is used for coupling excitation laser generated by the laser into the hollow-core optical fiber gas sample chamber; to-be-detected gas flows in the hollow-core optical fiber gas sample chamber, excitation laser is conducted, and a transmission light beam containing the excitation laser and Raman scattering light is output; the collecting device is used for separating excitation laser in the transmission light beam and outputting a light beam only containing Raman scattering; a small round hole is formed in an inlet of the spectrograph, spatial filtering is carried out, and the luminous flux lost when a light beam enters the spectrograph is reduced; and the spectrometer receives the Raman scattering to obtain the Raman spectrum of the gas to be detected. The luminous flux lost when the light enters the spectrograph is reduced, the light beam collection efficiency is improved, and the signal-to-noise ratio and the analysis sensitivity are improved.

The invention discloses a nano-enzyme-SERS (Surface Enhanced Raman Scattering) bifunctional sensor for detecting colorectal cancer markers with high sensitivity as well as a preparation method and application of the nano-enzyme-SERS bifunctional sensor. The preparation method comprises the following steps: coating a layer of platinum (Pt) on the surface of gold nanoparticles (AuNPs) by utilizing a chemical reduction method so as to form gold-platinum nanoparticles (Au (at) Pt NPs); assembling the synthesized Au (at) Pt NPs into an aminated capillary tube through electrostatic adsorption, so as to prepare a capillary tube SERS (Surface Enhanced Raman Scattering) substrate; the surface of Au (at) Pt NPs is modified with a marker aptamer through an Au-S bond, and the nano enzyme-SERS dual-function sensor is prepared. In the presence of hydrogen peroxide (H2O2), the Au (at) Pt NPs can catalyze the oxidation of 3, 3 ', 5, 5'-tetramethyl benzidine (TMB) to generate oxidized TMB (oxTMB) with a strong SERS (Surface Enhanced Raman Scattering) signal. When Hcy exists, the reductive sulfydryl of Hcy consumes hydroxyl free radicals (. OH) generated by H2O2 decomposition, so that TMB oxidation is inhibited, and SERS signal intensity is weakened. A linear regression equation of the logarithm of the Hcy concentration and the signal intensity is drawn according to the SERS signal intensity, so that quantitative detection of the Hcy is realized.

The invention provides a distributed optical fiber temperature measurement method and device, electronic equipment and a storage medium, and belongs to the technical field of optical fiber detection. Multi-dimensional data acquisition including light source power fluctuation data, detector dark current data, optical fiber loss distribution data and environment temperature and humidity data is realized; preprocessing the collected multi-dimensional data, constructing a light source power drift model and a detector sensitivity drift model, and fitting model parameters; and calculating a corresponding error correction coefficient based on the light source power drift model and the detector sensitivity drift model, correcting the ratio of anti-Stokes light intensity to Stokes light intensity of Raman scattering in combination with a dynamic correction result of an optical fiber attenuation coefficient by environment temperature and humidity data, and outputting calibration temperature data. Therefore, on the basis of the Raman scattering technology, light source power fluctuation and detector sensitivity drift core errors are eliminated through a multi-dimensional error compensation model, and the temperature measurement precision is improved.

The invention discloses a cable joint discharge monitoring system, which comprises a sensing layer, a data fusion layer and an analysis layer, and also discloses a cable joint discharge monitoring method, which comprises the following steps: monitoring the high-frequency current of a cable joint, acquiring a back Raman scattering signal of laser in a distributed optical fiber by an optical time domain reflection demodulation unit, obtaining the temperature of a measuring point, and monitoring the temperature of the cable joint. The analysis layer judges whether the temperature exceeds a temperature warning value or not, judges whether a high-frequency current pulse from the high-frequency current sensor is greater than a high-frequency current pulse warning value or not when the temperature exceeds the temperature warning value, and establishes a three-dimensional temperature field according to the temperature of the measuring point when the high-frequency current pulse is greater than the high-frequency current pulse warning value; the method comprises the following steps: acquiring a three-dimensional temperature field, performing spatio-temporal data alignment on the three-dimensional temperature field and high-frequency current acquired by a high-frequency current sensor, generating an abnormal region thermodynamic diagram, judging whether time and temperature data after alignment have interference or not, and performing three-dimensional positioning on a defective region and evaluating the severity of the defective region by an analysis layer when the interference does not exist.

The invention provides a preparation method and application of a high-sensitivity imprinted membrane for selectively detecting microcystic toxins (MC-LR) in water based on surface enhanced Raman scattering. The preparation method comprises the following steps: step 1, preparation of silver nanocubes; step 2, preparation of Ag NCs-coated TiO2 nanoparticles; step 3, preparation of an Ag NCs-coated TiO2 / PDMS composite membrane; according to the invention, a membrane technology, an SERS technology and MIT are combined, so that the prepared product has excellent physical and chemical properties of a PDMS membrane, high sensitivity of an SERS detection technology and high selectivity of MIT; the invention provides a new method for SERS detection and widens the application range.

The invention provides a distributed optical fiber temperature measurement positioning calibration method and system based on a Raman effect, and relates to the technical field of optical fiber temperature measurement calibration, and the method comprises the steps: obtaining a Raman scattering light signal, and extracting temperature distribution; performing expansion causal convolution and linear activation to obtain an optical fiber starting point coordinate prediction value; constructing a graph topological structure, and constructing a self-adaptive adjacent matrix based on a temperature gradient for feature extraction; lifting wavelet decomposition and self-adaptive denoising are carried out on the topological features of the graph, and registration calibration is carried out after a temperature field is reconstructed.

The invention belongs to the field of antibiotic analysis and detection, and discloses a quinolone drug SERS (Surface Enhanced Raman Scattering) detection method based on an improved silver nano-substrate and a spectral angle matching model. An improved Lee-Meisel method is adopted to synthesize silver nano sol with precisely controlled particle size, molecular adsorption is realized by utilizing electrostatic interaction of a positively charged quinolone drug and negatively charged silver nano particles, and a high-density Raman enhanced hot spot is formed after an agglomeration agent is added; the SERS spectrum is collected at the excitation wavelength of 785 nm and the integral time of 10 s, qualitative distinguishing of drugs is achieved by combining a spectrum angle matching model, and quantitative detection is achieved by constructing a standard curve through the linear relation between the characteristic peak intensity and the drug concentration logarithm. The detection limit of the four drugs is as low as 1.03-1.16 ppb, the classification accuracy rate reaches 100%, the method is obviously superior to existing similar methods, the detection matrix range is wide, such as animal food and dairy products, and universality and high sensitivity are both considered.

The invention discloses a method for rapidly detecting the type and content of bacteria in gas based on a Raman spectrum technology, and relates to the technical field of microbiological detection.The method comprises the steps that a gas sample is collected, dried and dewatered, and the sampling volume is determined; the method comprises the following steps: pre-filtering a gas sample, guiding the pre-filtered gas sample to a low-background filter membrane to enrich bacteria, and irradiating the enriched bacteria on the low-background filter membrane by adopting near-infrared laser to generate a scattered Raman signal; raman signals are collected, and only light in a bacteria Raman characteristic peak interval is allowed to pass through in cooperation with a narrow-band optical filter; performing feature extraction and pattern recognition on the Raman signals, classifying to judge the types of bacteria, comparing the intensity of the Raman signals with a calibration curve of bacteria with known concentration, and calculating the concentration of the bacteria in the gas in combination with the sampling volume. Through exclusive gas sampling pretreatment and surface enhanced Raman scattering and fusion of representative Raman peak intensity, rapid bacteria detection with strong interference resistance, stability, reliability, low detection limit, high quantitative accuracy and cross-batch comparability is realized.

The application relates to the field of surface-enhanced Raman scattering, and specifically provides a three-dimensional SnSe2 surface-enhanced Raman scattering substrate and a preparation method thereof. The three-dimensional SnSe2 surface-enhanced Raman scattering substrate comprises a filter layer, a plurality of filter holes are arranged on the filter layer, a SnSe2 nanostructure layer is fixedly arranged on the upper side of the filter layer, the SnSe2 nanostructure layer is composed of SnSe2 nanostructures, the SnSe2 nanostructure is SnSe2 nanoflower, the SnSe2 nanoflower covers the filter layer, and the SnSe2 nanoflower blocks the filter holes on the filter layer. No vertical gap exists in the SnSe2 nanoflower structure, which makes the local effect of the SnSe2 nanoflower on a light field better, so that the Raman signal enhancement factor is improved. The preparation method of the three-dimensional SnSe2 surface-enhanced Raman scattering substrate comprises the following steps: S1, preparing SnSe2 nanoflower; S2, preparing an aqueous solution of the SnSe2 nanoflower; and S3, performing suction filtration to obtain the SnSe2 surface-enhanced Raman scattering substrate. The preparation method does not use a molecular beam epitaxy method, and the cost is low.

The invention provides a dynamic Raman detection device and method based on a magnetic control cluster. The device comprises a magnetic SERS probe, a magnetic field generation unit, a Raman detection unit and an imaging unit, wherein the magnetic field generation unit is used for generating a programmable time-varying magnetic field to drive the magnetic SERS probe to form a dynamic micro-nano motor cluster; the Raman detection unit is used for performing laser irradiation on a magnetic control cluster area and collecting Raman scattering signals; the imaging unit is used for monitoring and positioning the magnetic control cluster in real time; a control unit; the to-be-detected area is located in the effective working space of the magnetic field generation unit; and the control unit is electrically connected with the magnetic field generation unit, the Raman detection unit and the imaging unit and is used for adjusting magnetic field parameters, synchronously controlling a detection time sequence and processing imaging and spectral data. According to the technical scheme, the dynamic motion characteristic and the surface Raman enhancement effect of the micro-nano motor cluster are combined, the external magnetic field is used for driving the probe to form a reconfigurable dynamic cluster, and high-sensitivity and accurate positioning detection in a complex environment is achieved.

The invention belongs to the technical field of surface enhanced Raman scattering (SERS) detection, and relates to an electrochemical Raman SERS substrate and a trace substance selective detection method. The electrochemical Raman SERS substrate comprises a bottom layer and a surface layer, the bottom layer is a conductive substrate, and the surface layer is a semiconductor oxide film. Taking an electrochemical Raman SERS substrate as a working electrode, immersing the working electrode into the detection liquid A to construct a three-electrode system, and carrying out laser Raman spectrum detection by utilizing a Raman spectrometer and an electrochemical workstation; the detection solution A comprises a target detection substance and an electrolyte solution. According to the technical scheme provided by the invention, electrochemical cycle regulation and control of semiconductor band gaps is matched and combined with molecular HOMO-LUMO energy levels, so that precise recognition of a single component in a mixture can be realized; according to the technical scheme, the regulation and control flexibility is high, and multi-component detection can be completed without replacing the substrate. The trace substance selective detection method is wide in applicability, simple, convenient and efficient to operate, free of complex pretreatment and suitable for on-site rapid screening.

The invention relates to a surface-enhanced flexible Raman substrate, a surface-enhanced Raman sensor for nano-plastic trace detection and a preparation method of the surface-enhanced Raman sensor. The preparation method of the surface-enhanced flexible Raman substrate comprises the following steps: preparing a colloidal solution by taking BNCs, a CS solution and a HAuCl4 aqueous solution as raw materials; the preparation method specifically comprises the following steps: dispersing an aqueous solution of HAuCl4 into an aqueous solution of BNCs, adding pvp for physical mixing and stirring, and then adding ethanol to obtain a mixture; and irradiating the mixture with laser, washing with deionized water for three times to obtain a BNCs / AuNWs colloidal solution, dropwise adding a CS solution, stirring, and carrying out suction filtration on the colloidal solution to obtain the BNCs / AuNWs coated CS surface-enhanced Raman scattering substrate. The CS substrate enhances molecular adsorption, so that the adsorption rate of the nano-scale plastic particles is greatly improved, the gold nanoparticles generate an enhanced LSPR effect on the surface of the substrate, a Raman signal is improved by 60-63 times, and the detection efficiency is improved.

The invention discloses a gold-silver alloy nanoparticle interface modified copper-zinc-tin-sulfur-selenium film, a preparation method thereof and a solar cell, and belongs to the technical field of photoelectric material new energy. Gold-silver alloy nanoparticles are uniformly distributed on the surface of the copper-zinc-tin-sulfur-selenium film. According to the invention, interface modification is carried out on the CZTSSe film by using the gold-silver alloy nanoparticles, so that the light absorption performance, Raman scattering performance and the like of the CZTSSe film are effectively improved, and then the performance of collection efficiency, open-circuit voltage, short-circuit current density, filling factors and the like of the solar cell is improved by applying the interface-modified CZTSSe to the solar cell. Therefore, the solar cell has more excellent use performance.

A label-free method for detecting tryptophan and kynurenine in serum based on surface-enhanced Raman scattering (SERS) technology is disclosed, belonging to the field of molecular SERS detection using Raman spectroscopy. The purpose of this invention is to address the problems of expensive equipment, cumbersome operation, and time-consuming analysis in traditional methods for detecting Trp and Kyn molecules, which are difficult to meet the needs of real-time clinical testing, and the current lack of research in the field of direct and simultaneous detection of Trp and Kyn molecules in serum based on label-free SERS technology. Method: 1. Preparation of gold-core tellurium-shell nanoparticles; 2. Preparation of Au@TeNPs SERS substrate using a self-assembly method; 3. SERS detection of tryptophan and kynurenine molecules. This invention, based on the Au@TeNPs SERS substrate, achieves for the first time simultaneous and rapid SERS detection of Trp and Kyn molecules within physiological concentration ranges in serum media. The detection method is rapid, economical, and has significant potential for clinical application.

A kind of distributed multi-parameter sensing system based on multi-core optical fiber, including laser, laser light source is sent to the signal generator input trigger pulse drive respectively with the signal input end of phase-sensitive optical time domain reflectometer based on Rayleigh scattering and its demodulation device, Raman optical time domain reflectometer based on Raman scattering and its demodulation device, Brillouin optical time domain reflectometer based on Brillouin scattering and its demodulation device are connected, the signal output end of phase-sensitive optical time domain reflectometer and its demodulation device, Raman optical time domain reflectometer and its demodulation device, Brillouin optical time domain reflectometer and its demodulation device is connected with the signal input end of multi-core optical fiber through multi-core optical fiber fan-in fan-out module;The present application utilizes the principle of space division multiplexing, each fiber core in optical cable as separate sensing channel carries out measurement and signal transmission;Multi-core optical fiber fuses three kinds of distributed optical fiber sensing systems together, realizes in-situ measurement and mutual compensation decoupling of temperature, strain and vibration, improves the measurement precision of sensing system.

The invention discloses a Raman scattering temperature measurement monitoring system based on a long-distance optical fiber, which relates to the technical field of optical fiber sensing temperature measurement, and comprises a step of injecting pulse laser to a sensing optical fiber through a laser transmitting module to excite backward Raman scattering light. The receiving and separating module separates the scattered light into a Stokes light signal and an anti-Stokes light signal. The processing and positioning module converts the signal strength into data distributed along the optical fiber position. And the temperature demodulation module establishes a calibration equation based on the strength ratio of the two, and calculates initial temperature data along the optical fiber according to the calibration equation. And the compensation and correction module constructs a correction model fusing the inherent attenuation and external disturbance characteristics of the optical fiber, compensates and corrects the initial data, and finally generates accurate temperature field data distributed along the optical fiber. According to the system, the spatial consistency, absolute precision and long-term environmental stability of long-distance distributed temperature measurement are improved through accurate calculation of a scattered light intensity ratio and systematic error modeling compensation.

The application relates to a surface enhanced Raman scattering (SERS) substrate, a preparation method and application thereof, and belongs to the technical field of Raman spectrum detection. The substrate comprises, from bottom to top, a substrate layer, a distributed Bragg reflector, a chalcogen phase change material functional layer and a nanoscale metal structure layer. The distributed Bragg reflector is composed of a periodic structure stack of medium materials with different refractive indexes. The distributed Bragg reflector is coupled with the nanoscale metal structure layer to excite a Tamm state. The chalcogen phase change material functional layer can realize reversible regulation of amorphous state and crystalline state under external light excitation, changes the Tamm state resonance wavelength to regulate the SERS enhancement effect. The application realizes high-sensitivity detection through double enhancement of the Tamm state and localized surface plasmon resonance, has the characteristics of non-volatility, reconfigurability, high reproducibility and design flexibility, is convenient to operate, stable in performance, and is suitable for fields of chemical biological sensing, laboratory chip systems and optical encryption.

A temperature strain separable dynamic and static combined measurement distributed optical fiber sensing system, comprising: laser, optical modulator, radio frequency signal generator, optical filter, DFB laser, polarization controller, first acoustooptic modulator, depolarizer, erbium-doped fiber amplifier, two optical circulators, optical wavelength division multiplexer, receiving module, signal acquisition and processing module are arranged in sequence, the application carries out temperature sensing to the back Raman scattering light of the pulse while receiving the Rayleigh scattering light of the detection pulse, and controls the time interval of adjacent pump pulse and detection pulse to carry out three-bit pulse coding and decoding, so that the back Raman scattering signals of individual pulse in pulse pair are separated in time, and finally the simultaneous measurement of dynamic variable (vibration) and static variable (temperature, static strain) is realized and the spatial resolution of measurement is ensured not to be lost.

The invention relates to the technical field of electrical equipment testing, and particularly provides a space charge detection device and method based on optical measurement. The space charge detection device based on optical measurement comprises a sensing acquisition array which is uniformly distributed around detected equipment in the circumferential direction, full-surrounding detection of space charges is achieved, collaborative design of four optical detection technologies is adopted, multi-dimensional detection of the space charges is achieved through the complementary effect of Raman scattering, the photoacoustic effect, LIBS and the photoelectric effect, and the detection accuracy of the space charges is improved. The detection limitation of a single technology is made up; according to the space charge detection method based on optical measurement, a space-time synchronization-weight distribution-feature fusion algorithm and a signal-to-noise ratio-based adaptive weight distribution fusion algorithm are adopted, space-time synchronization calibration and Kalman filtering are combined, the problems of space-time inconsistency and random errors of multi-source data are solved, and the precision of data fusion is improved.

According to an aspect there is provided an apparatus for Raman light detection, said apparatus comprising: an illumination unit, configured to provide a wavelength modulation for generating and outputting wavelength modulated laser light towards a sample for inducing generation of Raman scattered light from the sample; a wavelength filter for filtering the Raman scattered light; and a light detector, configured to receive the Raman scattered light filtered by the wavelength filter and to provide an instantaneous response signal dependent on an intensity of the received Raman scattered light.

The application belongs to the technical field of thiocyanate detection, and specifically relates to a method for detecting thiocyanate based on inherent internal standard surface-enhanced Raman scattering substrate, which comprises the following steps: S1. Preparing a thiocyanate standard curve: taking the thiocyanate concentration as the horizontal coordinate, and the ratio of the peak intensity at the characteristic peak of thiocyanate with different concentrations to the peak intensity at the internal standard peak of a bare silver SERS chip as the vertical coordinate to establish a linear regression equation, thereby obtaining the thiocyanate standard curve; S2. Detecting experimental precision; S3. Quantitatively detecting the thiocyanate content: detecting the SERS signals of the thiocyanate sample to be measured and the bare silver SERS chip, and comparing the SERS signals with the thiocyanate standard curve in step S1 to obtain the thiocyanate content to be measured. In the application, the inherent peak generated by the substrate silver oxide in the bare silver SERS chip is used as an internal standard reference, no additional internal standard substance is added, the substrate detection performance is not affected, the linear fitting of the standard curve equation is better, the influence of errors is greatly reduced, the quantification is more accurate, and the thiocyanate can be rapidly detected.

The invention discloses a method for realizing optical cable fiber core health prediction by using a B-OTDR technology, which comprises the following steps: a multi-physical quantity fusion detection module synchronously obtains Brillouin scattering and Raman scattering signals by using a double-pulse modulation technology, separates two kinds of scattered light through frequency division multiplexing, and constructs a strain-temperature decoupling model; and the dynamic self-adaptive sampling module automatically switches sampling resolution according to the position of the optical fiber, adopts high-resolution continuous scanning on a historical fault high-incidence area, adopts low-resolution sparse sampling on a normal area, and automatically triggers local encryption sampling when an abnormal event is detected. The double pulses are respectively calculated by adopting a double-pulse modulation technology, so that the prediction accuracy is improved; dynamic self-adaptive sampling is adopted, segmented sampling is carried out on a high fault area and a normal area, meanwhile, local sampling is carried out on an abnormal section, the invalid data volume is reduced, and meanwhile the monitoring precision of a key area is ensured.

Provided is a method for generating a Raman spectrum with a high SN ratio using spectral data in a quenching process, wherein the Raman spectrum is generated by separating Raman scattered light from fluorescence by a method free of arbitrariness.　The method for generating a Raman spectrum comprises: a step for repeating a procedure in which a sample is irradiated with laser light, Raman scattered light that is scattered from the sample and fluorescence that is radiated from the sample are received, and a spectrum that contains the Raman scattered light and the fluorescence is obtained, and recording a first spectrum, a second spectrum, ..., and an nth spectrum; a step for determining, for each of the n recorded spectra, the intensity of the Raman scattered light as the product of an exposure time and the power of the laser light with which the sample is irradiated; a step for determining the intensity of the fluorescence for each of the n recorded spectra; and a step for using the intensity of the determined Raman scattered light and the intensity of the determined fluorescence to determine a Raman spectrum by the least squares method.

Raman spectrometer with a high-power laser diode (16) for emission of laser light (31) which has a central wavelength (λ) La ) in the blue spectral range, with a measuring chamber (20) through which a gas (22) flows, with first focusing means (18) for focusing the laser light (31) into the measuring chamber (20) and with a spectrally resolving detector (70) and with second focusing means (21) for imaging Raman scattered light (34) generated in the measuring chamber (20) into the spectrally resolving detector (70), characterized in that an optical short-pass filter (19) is arranged in the beam path of the laser light (31) between the high-power laser diode (16) and the measuring chamber (20), the cutoff wavelength (λ) of which KP ) is longer than the central wavelength (λ La ) of the laser light (31).

The invention relates to a Raman spectroscopy device for measuring the concentration of a gas (22). The essential aspect of the invention is that the Raman spectroscopy device (30) in the gas measurement chamber (20, 56) has a sleeve-shaped component (40), wherein the sleeve-shaped component (40) has a cavity (41) inside, and wherein the gas to be measured is conductable in the longitudinal direction essentially through the cavity (41) of the sleeve-shaped component (40). that the sleeve-shaped component (40) has openings (42) on its outer surface through which the laser light of the high-power laser (14) can be directed into or out of the cavity (41), that the sleeve-shaped component (40) has at least one aperture section (43) which projects into the cavity (41), that the sleeve-shaped component (40) has an outlet opening (44) on its outer surface for supplying Raman scattering to the spectral analysis unit (38), that the aperture section (43) is geometrically arranged between the openings (42) through which laser light enters and exits the cavity (41) and the outlet opening (44), that the aperture section (43) is designed in the form of at least two aperture flaps directed inwards into the component.

The application provides a method for detecting PFAS based on a three-dimensional Ag / NiFe-LDHs surface enhanced Raman scattering substrate and ion pair extraction, and belongs to the technical field of PFAS detection, and comprises the following steps: first, a three-dimensional Ag / NiFe-LDHs SERS substrate is prepared; then, ion pair extraction-dissociation treatment is performed on a water sample to be measured to obtain a detection solution; finally, the substrate is immersed in the detection solution for adsorption, a spectrum is collected by using a Raman spectrometer, and semi-quantitative detection of PFAS in the water sample is realized according to the linear relationship between the characteristic peak intensity and the logarithm of the molar concentration of PFAS. The application realizes the synergistic application of the three-dimensional Ag / NiFe-LDHs SERS substrate and the ion pair extraction technology and the indirect detection of PFAS, improves the detection difficulty of weak PFAS Raman signals and difficult enrichment, improves the detection sensitivity and adaptability of PFAS in the water sample, and lays an application foundation for rapid monitoring of PFAS pollution in environmental water.