JP7386444B2 - Raman spectroscopy spectrum analysis device and Raman spectroscopy spectrum analysis method - Google Patents

Description

The present disclosure relates to a Raman spectroscopy spectrum analysis device and a Raman spectroscopy spectrum analysis method.

Raman spectroscopy is a technique for measuring the concentration of a specific substance in a sample containing multiple types of substances. In Raman spectroscopy, molecules and crystals have unique vibrational energy depending on their structure. It is an application of the phenomenon of having a wavelength different from that of a material, so it has excellent selectivity for specific substances.

However, depending on the irradiated light and the type of sample, fluorescence may be emitted. Fluorescent light emits light at a wavelength longer than the wavelength of the irradiating light. In particular, when measuring Stokes Raman scattered light, the spectrum of the Raman light is measured in a wavelength band longer than the wavelength of the irradiated light, so the spectrum of the Stokes Raman scattered light and the fluorescence spectrum may overlap.

Therefore, there is a need for a method to easily remove the influence of fluorescence from spectra measured by Raman spectroscopy. For example, Patent Document 1 discloses a method of irradiating a measurement object with excitation light of two different wavelengths, measuring a Raman spectrum, and deriving a difference spectrum. For example, Patent Document 2 discloses that a measurement target is irradiated with excitation light of two different preset wavelengths, and emitted light including Raman scattered light emitted from the measurement target is selected from emitted light of a specific wavelength band. Disclosed is a method for selecting a light beam and calculating a difference between peak intensities of the selected light beams.

US Patent Application Publication No. 2008/0204715 Japanese Patent Application Publication No. 2015-148535

However, the conventional technique described in Patent Document 1 shifts the wavelength of the excitation light and irradiates the excitation light with two different wavelengths, so it is necessary to measure twice, which is time-consuming. In addition, in the conventional technology described in Patent Document 2, it is necessary to determine in advance the wavelength band to be selected depending on the object to be measured, and furthermore, the wavelength band of the excitation light is adjusted so that the intensity of the light in the selected wavelength band is different. It is time-consuming as it is necessary to shift the

Therefore, the present disclosure provides a Raman spectroscopy spectrum analysis device and a Raman spectroscopy spectrum analysis method that can easily remove the influence of fluorescence from a spectrum measured by Raman spectroscopy.

A Raman spectroscopic spectrum analyzer according to one aspect of the present disclosure includes a light source that irradiates an object to be measured with excitation light, a spectrometer that measures the spectrum of the light by dispersing the light, and a device connected to the spectrometer. a processor, the spectrometer acquires a spectrum of the excitation light irradiated from the light source, and measures a spectrum of scattered light scattered from the object to be measured by the irradiation of the excitation light. The processor includes an analysis unit that calculates a degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, and analyzes the spectrum of the scattered light based on the calculated degree of correlation.

Further, a Raman spectroscopic spectrum analysis method according to an aspect of the present disclosure includes an irradiation step of irradiating an object to be measured with excitation light, acquiring a spectrum of the excitation light irradiated to the object to be measured, and a measuring step of measuring a spectrum of scattered light scattered from the object to be measured by irradiation with light; and calculating a degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, and based on the calculated degree of correlation. and an analysis step of analyzing the spectrum of the scattered light.

Note that these general or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM. , an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

According to the present disclosure, there are provided a Raman spectroscopy spectrum analysis device and a Raman spectroscopy spectrum analysis method that can easily remove the influence of fluorescence from a spectrum measured by Raman spectroscopy.

FIG. 1 is a block diagram showing an example of the functional configuration of a Raman spectroscopic spectrum analysis apparatus according to an embodiment. FIG. 2 is a flowchart illustrating an example of the Raman spectroscopy spectrum analysis method according to the embodiment. FIG. 3 is a flowchart showing a detailed flow of the analysis steps shown in FIG. FIG. 4 is a diagram showing the spectrum of excitation light in Experimental Example 1 and Experimental Example 2. FIG. 5 is a diagram showing spectra of scattered light in Experimental Example 1 and Experimental Example 2. FIG. 6 is a diagram showing correlation spectra in Experimental Example 1 and Experimental Example 2. FIG. 7 is a diagram showing the spectrum of excitation light in Experimental Example 3 and Experimental Example 4. FIG. 8 is a diagram showing spectra of scattered light in Experimental Examples 3 and 4. FIG. 9 is a diagram showing correlation spectra in Experimental Example 3 and Experimental Example 4. FIG. 10 is a diagram showing the spectrum of excitation light in Example 1. FIG. 11 is a diagram showing the spectrum and correlation spectrum of scattered light in Example 1. FIG. 12 is a diagram showing the correlation spectrum in Example 1 and the FTIR spectrum of ZnDTP. FIG. 13 is a diagram illustrating an example of a Raman spectroscopy spectrum analysis system including a Raman spectroscopy spectrum analysis device according to the present disclosure.

An overview of one aspect of the present disclosure is as follows.

A Raman spectroscopic spectrum analyzer according to one aspect of the present disclosure includes a light source that irradiates an object to be measured with excitation light, a spectrometer that measures the spectrum of the light by dispersing the light, and a device connected to the spectrometer. a processor, the spectrometer acquires a spectrum of the excitation light irradiated from the light source, and measures a spectrum of scattered light scattered from the object to be measured by the irradiation of the excitation light. The processor includes an analysis unit that calculates a degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, and analyzes the spectrum of the scattered light based on the calculated degree of correlation.

As a result, in the spectrum of the scattered light, a peak (Raman peak) obtained by shifting the spectrum of the excitation light by a predetermined wave number is emphasized, and a peak that has no correlation with the spectrum of the excitation light is suppressed. Therefore, the degree of correlation represents the spectrum of scattered light from which the influence of noise such as fluorescence has been removed. Therefore, according to the Raman spectroscopic spectrum analyzer according to one aspect of the present disclosure, the influence of fluorescence can be easily removed from the spectrum measured by Raman spectroscopy (so-called spectrum of scattered light).

For example, in the Raman spectroscopy spectrum analysis device according to one aspect of the present disclosure, the light source may emit light having a plurality of emission spectrum peaks with different emission center wavelengths.

Thereby, according to the Raman spectroscopic spectrum analysis device according to one aspect of the present disclosure, the accuracy of calculating the degree of correlation based on the shape of the spectrum of the excitation light emitted from the light source is improved.

For example, in the Raman spectroscopic spectrum analyzer according to one aspect of the present disclosure, the measurement unit may detect the scattered light including the wavelength band of the excitation light during, before, or after measurement of the spectrum of the excitation light. The spectrum of the excitation light may be obtained by measuring the spectrum.

Thereby, according to the Raman spectroscopic spectrum analyzer according to one aspect of the present disclosure, the spectrum of excitation light can be acquired when measuring the spectrum of scattered light, so the accuracy of calculating the degree of correlation is improved.

For example, in the Raman spectroscopic spectrum analysis device according to one aspect of the present disclosure, the analysis unit performs quality determination of the spectrum of the excitation light at least prior to calculating the degree of correlation, and the processor further determines the quality of the spectrum of the excitation light. a control unit that causes the measuring unit to acquire the spectrum of the excitation light and measure the spectrum of the scattered light when the quality of the light is determined to be lower than a predetermined quality; The spectrum of the scattered light may be analyzed based on the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, which is obtained by the control unit causing the measurement unit to perform the analysis.

Thereby, excitation light of a predetermined quality or higher can be used for measurement. Furthermore, even if excitation light that does not meet a predetermined quality has to be used for measurement, analysis can be performed by calculating the degree of correlation. Therefore, according to the Raman spectroscopic spectrum analysis device according to one aspect of the present disclosure, the accuracy of calculating the degree of correlation is improved.

For example, in the Raman spectroscopic spectrum analysis device according to one aspect of the present disclosure, the measurement unit acquires the spectrum of the excitation light and measures the spectrum of the scattered light multiple times, and the analysis unit The degree of correlation between the spectrum of light and the spectrum of the scattered light is calculated, a correlation degree with a high peak intensity is selected from among the plurality of calculated correlation degrees, and the scattering is performed based on the selected correlation degree. The spectrum of light may also be analyzed.

As a result, for example, even if the state of the excitation light becomes unstable during measurement, the state of the excitation light can be stabilized by acquiring the spectrum of the excitation light and measuring the spectrum of the scattered light multiple times. The possibility of obtaining the excitation light spectrum and the scattered light spectrum increases when the Therefore, according to the Raman spectroscopic spectrum analyzer according to one aspect of the present disclosure, a more reliable degree of correlation can be obtained.

For example, in the Raman spectroscopy spectrum analysis apparatus according to one aspect of the present disclosure, the light source includes a light emitting element, and the temperature of the light emitting element, the amount of current conducted to the light emitting element, the frequency of the excitation light, and the light source The spectrum of the excitation light may be changed by changing the oscillation state of the excitation light emitted from the light emitting element based on at least one parameter of the attachment position of the external resonator to the light emitting element.

Thereby, the spectrum of the excitation light can be adjusted to a desired state, so that more appropriate excitation light can be irradiated depending on the object to be measured. Therefore, for example, an object to be measured can be irradiated with a spectrum of excitation light having a characteristic peak shape. Therefore, the calculation accuracy of the degree of correlation is improved, so that the Raman spectroscopic spectrum analyzer according to one aspect of the present disclosure can accurately measure the spectrum of scattered light.

Further, in the Raman spectroscopic spectrum analysis apparatus according to one aspect of the present disclosure, the analysis section may analyze multiple types of components contained in the object to be measured when analyzing the spectrum of the scattered light.

Thereby, according to the Raman spectroscopy spectrum analysis device according to one aspect of the present disclosure, it is possible to analyze the concentrations and states of multiple types of components contained in the object to be measured.

Further, a Raman spectroscopic spectrum analysis method according to an aspect of the present disclosure includes an irradiation step of irradiating an object to be measured with excitation light, acquiring a spectrum of the excitation light irradiated to the object to be measured, and a measuring step of measuring a spectrum of scattered light scattered from the object to be measured by irradiation with light; and calculating a degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, and based on the calculated degree of correlation. and an analysis step of analyzing the spectrum of the scattered light.

As a result, in the spectrum of the scattered light, a peak (Raman peak) obtained by shifting the spectrum of the excitation light by a predetermined wave number is emphasized, and a peak that has no correlation with the spectrum of the excitation light is suppressed. Therefore, the degree of correlation represents the spectrum of scattered light from which the influence of noise such as fluorescence has been removed. Therefore, according to the Raman spectroscopy spectrum analysis method according to one aspect of the present disclosure, the influence of fluorescence can be easily removed from the spectrum measured by Raman spectroscopy (so-called spectrum of scattered light).

Note that these comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM. , a computer program, and a recording medium.

Embodiments of the present disclosure will be specifically described below with reference to the drawings.

Note that the embodiments described below are all inclusive or specific examples. The numerical values, shapes, components, arrangement positions and connection forms of the components, steps, order of steps, etc. shown in the following embodiments are merely examples, and do not limit the present disclosure. Further, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the most significant concept will be described as arbitrary constituent elements. Further, each figure is not necessarily strictly illustrated. In each figure, substantially the same components are denoted by the same reference numerals, and overlapping explanations may be omitted or simplified.

(Embodiment)
[Raman spectroscopic spectrum analyzer]
First, a Raman spectroscopic spectrum analysis apparatus according to an embodiment will be described. FIG. 1 is a block diagram showing an example of the functional configuration of a Raman spectroscopic spectrum analysis apparatus 100 according to an embodiment. In FIG. 1, the movement of light is shown by a broken line, and the direction of signal transmission is shown by a solid line.

The Raman spectroscopic spectrum analyzer 100 irradiates the object to be measured with excitation light, calculates the degree of correlation between the spectrum of the irradiated excitation light and the spectrum of scattered light scattered from the object to be measured by the irradiation of the excitation light, The spectrum of scattered light is analyzed based on the calculated degree of correlation. As shown in FIG. 1, the Raman spectroscopic spectrum analysis apparatus 100 includes a light source 10, a spectrometer 20, and a processor 30. Each configuration will be explained below.

[light source]
The light source 10 irradiates the object to be measured with excitation light. The excitation light may be any of ultraviolet light, visible light, and infrared light. Among these, the excitation light is preferably visible light. Furthermore, the excitation light may have multiple emission spectrum peaks with different emission center wavelengths. That is, the light source 10 may emit light having a plurality of emission spectrum peaks with different emission center wavelengths. In this case, the multiple emission spectrum peaks do not need to be completely independently separated. For example, the excitation light may have two emission spectrum peaks with different emission center wavelengths close to each other, and one emission spectrum peak with the tip of the peak divided into two peaks. This improves the accuracy of calculating the degree of correlation based on the shape of the spectrum of the excitation light emitted from the light source 10. Therefore, since an inexpensive visible light laser can be used as the light source 10 and an optical system for visible light can be used, manufacturing costs can be reduced.

The light source 10 includes a light emitting element (not shown), and is based on at least one parameter of the temperature of the light emitting element, the amount of current conducted to the light emitting element, the frequency of excitation light, and the mounting position of the external resonator with respect to the light source. Alternatively, the spectrum of the excitation light may be changed by changing the oscillation state of the excitation light emitted from the light emitting element. Thereby, the spectrum of excitation light can be adjusted to a desired state. Therefore, for example, the object to be measured can be irradiated with excitation light having a characteristic peak shape such that the peak of the excitation light spectrum is divided into two. Therefore, the accuracy of calculating the degree of correlation is improved, so that the spectrum of scattered light can be analyzed with higher accuracy.

The light source 10 may be composed of, for example, a semiconductor laser whose output pulse repetition frequency and pulse width can be controlled over a relatively wide range. The light source 10 is, for example, a distributed feedback (DFB) laser, a distributed reflection Bragg (DBR) laser, a Fabry-Perot (FP) laser, an external cavity laser, or a vertical cavity surface emitting laser (VCSEL). Surface Emitting Laser), etc. Among these, the light source 10 may be a Fabry-Perot semiconductor laser. This allows Raman spectroscopy to be performed at a lower cost than using high-quality lasers used in conventional Raman spectroscopy.

Furthermore, as will be described later, the Raman spectroscopic spectrum analyzer 100 analyzes the spectrum of scattered light based on the degree of correlation between the spectrum of excitation light and the spectrum of scattered light, so it is not easily influenced by the quality of the light source. Therefore, according to the Raman spectroscopic spectrum analyzer 100, even if a laser of lower quality than that used in conventional Raman spectroscopy is used, the influence of noise can be easily removed from the spectrum of scattered light. , a high S/N ratio can be obtained. Furthermore, since a relatively inexpensive laser such as a Fabry-Perot semiconductor laser can be used, Raman spectroscopy can be performed at low cost.

Note that when a laser used as an oscillation source of excitation light is of high quality, it means that the light emitted from the laser has high monochromaticity. Monochromaticity means that the light emitted by a laser contains only a single wavelength component. In an actual laser, oscillation is affected by the purity, structure, and temperature of the element, as well as the characteristics of the optical system (such as an external resonator) placed to stabilize the wavelength of the emitted light. The wavelength of the light emitted is not necessarily a single wavelength. The emission spectrum of an ideally high-quality laser includes a wavelength component distribution approximated by a single Gaussian or Lorentzian function with an extremely narrow half-width. On the other hand, in a low-quality laser, the emission spectrum includes a wavelength component distribution in which the half-width of an approximation function such as a Gaussian function or a Lorentzian function is wide. Furthermore, in a low-quality laser, the emission spectrum may exhibit asymmetrical or multiple emission peaks, as expressed by a superposition of Gaussian functions having multiple center wavelengths and half-widths. In Raman spectroscopy, the wavelength of Raman scattered light is expressed by the difference from the wavelength of excitation light, so when a laser with a wide half-value width is used as the light source 10, the width of the spectrum of Raman scattered light also becomes wide. This reduces the measurement accuracy of Raman spectroscopy.

Therefore, in this embodiment, the quality of the excitation light spectrum is preferably evaluated based on the monochromaticity of the emission spectrum as described above. For example, the emission spectrum of a high-quality laser should not exhibit multiple emission peaks, be approximated by a single Gaussian or Lorentzian function, and have a sufficiently narrow half-width. In this case, the desired half-width value is, for example, 3 nm or less for a 785 nm laser. Note that the value of this half-value width is just an example, and is not necessarily absolute, and may be determined as appropriate depending on the measurement object and required measurement accuracy.

[Spectrometer, measurement section]
The spectrometer 20 measures the spectrum of light by dividing the light into spectra. More specifically, the spectrometer 20 includes a measurement unit 22 that acquires the spectrum of excitation light irradiated from a light source and measures the spectrum of scattered light scattered from the object to be measured by the irradiation of the excitation light. . The spectrometer 20 may further include a spectroscopic section (not shown) and a filter (not shown).

The light reflected and scattered by the object to be measured due to the irradiation with the excitation light enters the spectrometer 20 . The reflected light has the same wavelength as the excitation light, and is called Rayleigh light. The light incident on the spectrometer 20 is incident on a filter (not shown). The filter is, for example, a bandstop filter that passes scattered light and removes Rayleigh light. The scattered light that has passed through the filter is separated into lights for each wavelength band by a spectrometer. The intensity of the light in each wavelength band separated by the spectroscopy section is measured by the measurement section 22. At this time, the measurement unit 22 may measure the spectrum of the excitation light in advance, or may acquire the spectrum of the excitation light measured in advance. Here, "obtaining" includes not only simply obtaining but also measuring.

For example, the measurement unit 22 may acquire the spectrum of the excitation light by measuring the spectrum including the wavelength band of the excitation light during, before, or after the measurement of the spectrum of the scattered light. This makes it possible to obtain the spectrum of the excitation light during measurement, thereby improving the accuracy of calculating the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light.

[Processor, measurement unit, control unit]
The processor 30 performs information processing related to the control of the spectrometer 20 and information processing for analyzing the spectra of the excitation light and scattered light output from the spectrometer 20. The processor 30 includes an analysis section 40 and a control section 50. Processor 30 is connected to spectrometer 20 . The processor 30 may be connected to the spectrometer 20 by wireless communication such as Bluetooth (registered trademark) or wired communication such as Ethernet (registered trademark). The processor 30 may be installed in a computer, for example, or may be installed together with the light source 10 and the spectrometer 20 in one device.

The analysis unit 40 calculates the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, and analyzes the spectrum of the scattered light based on the calculated degree of correlation. Note that the degree of correlation represents the likelihood that the shape of each point in the spectrum of scattered light matches the shape of the excitation light spectrum. A method for calculating the degree of correlation will be described later with reference to FIG. 3. In this way, in order to analyze the spectrum of scattered light based on the degree of correlation, the peak (Raman peak) where the spectrum of excitation light is shifted by a predetermined wave number in the spectrum of scattered light is emphasized and correlated with the spectrum of excitation light. Peaks without are suppressed. Therefore, the degree of correlation represents the spectrum of scattered light from which the influence of noise such as fluorescence has been removed. Therefore, according to the Raman spectroscopic spectrum analyzer 100, the influence of fluorescence can be easily removed from the spectrum measured by Raman spectroscopy (so-called spectrum of scattered light).

In analyzing the spectrum of scattered light, the analysis unit 40 analyzes multiple types of components contained in the object to be measured. This makes it possible to analyze the concentrations and states of multiple types of components contained in the object to be measured.

Furthermore, the analysis unit 40 may determine the quality of the spectrum of the excitation light at least prior to calculating the degree of correlation. At this time, if the analysis unit 40 determines that the quality of the excitation light is lower than a predetermined quality, the control unit 50 causes the measurement unit 22 to acquire the spectrum of the excitation light and measure the spectrum of the scattered light. . Next, the analysis section 40 analyzes the spectrum of the scattered light based on the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light obtained by the measurement section 22. Thereby, excitation light of a predetermined quality or higher can be used for measurement. Furthermore, even if excitation light that does not meet a predetermined quality has to be used for measurement, analysis can be performed by calculating the degree of correlation. Therefore, the accuracy of calculating the degree of correlation is improved.

Note that, as described above, the quality of the excitation light spectrum is determined based on the monochromaticity of the emission spectrum. For example, the analysis unit 30 determines whether the emission spectrum of the excitation light emitted from the light source 10 (i) shows a plurality of emission peaks or not; and (ii) whether it can be approximated by a single Gaussian function or Lorentzian function. , and (iii) the quality of the excitation light spectrum may be determined based on whether the half-width of the emission peak is narrower than a threshold value. The threshold value may be determined as appropriate depending on the measurement target and measurement accuracy.

Note that the measurement unit 22 may acquire the spectrum of excitation light and measure the spectrum of scattered light multiple times. At this time, the analysis unit 40 calculates the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, and selects the degree of correlation with the highest peak intensity from among the plurality of calculated degrees of correlation. Analyze the spectrum of scattered light based on the degree of correlation. As a result, for example, even if the state of the excitation light becomes unstable during measurement, the state of the excitation light can be stabilized by acquiring the spectrum of the excitation light and measuring the spectrum of the scattered light multiple times. The possibility of obtaining the excitation light spectrum and the scattered light spectrum increases when the Therefore, a more reliable degree of correlation can be obtained.

[Raman spectroscopy spectrum analysis method]
Next, an example of a Raman spectroscopic analysis method will be described with reference to FIG. 2. FIG. 2 is a flowchart illustrating an example of the Raman spectroscopy spectrum analysis method according to the embodiment.

The spectroscopic spectrum analysis method according to the embodiment includes an irradiation step S100 of irradiating an object to be measured with excitation light, acquiring a spectrum of the excitation light irradiated to the object to be measured, and irradiating the object with the excitation light. a measurement step S200 of measuring the spectrum of the scattered light scattered from the source; and an analysis step of calculating the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, and analyzing the spectrum of the scattered light based on the calculated degree of correlation. S300.

Each step will be explained in more detail below.

As shown in FIG. 2, in the Raman spectroscopy spectrum analysis method, first, the light source 10 irradiates the object to be measured with excitation light (irradiation step S100). The excitation light may be any of ultraviolet light, visible light, and infrared light. The excitation light is, for example, laser light. At this time, the light source 10 is, for example, a Fabry-Perot semiconductor laser. In the Raman spectroscopy spectrum analysis method, a high S/N ratio can be obtained even when using a laser of lower quality than the high quality laser used in conventional Raman spectroscopy. This is because by calculating the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, the influence of noise such as fluorescence can be easily removed from the spectrum of the scattered light.

Next, the measurement unit 22 acquires the spectrum of the excitation light irradiated to the object to be measured, and measures the spectrum of the scattered light scattered from the object to be measured by the irradiation of the excitation light (measurement step S200). As described above, the measurement unit 22 may measure the spectrum of the excitation light in advance, or may acquire the spectrum of the excitation light measured in advance.

Next, the analysis unit 40 calculates the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, and analyzes the spectrum of the scattered light based on the calculated degree of correlation (analysis step S300). Here, the analysis step S300 will be explained in more detail with reference to FIG. FIG. 3 is a flowchart showing the detailed flow of analysis step S300 shown in FIG.

In analysis step S300, the analysis unit 40 performs preprocessing on the spectrum of scattered light (step S301). More specifically, the analysis unit 40 performs DC offset removal, cosmic ray removal, and baseline correction on the spectrum of the scattered light.

Next, the analysis unit 40 determines the peak position of the spectrum of the excitation light (step S302). This determines the peak wavelength of the excitation light, which serves as a reference for wave number calculation.

Next, the analysis unit 40 converts the wavelength of the excitation light spectrum and the wavelength of the scattered light spectrum into Raman shift amounts (that is, wave numbers) (step S303). Next, the analysis unit 40 extracts the first calculation interval from the spectrum of the scattered light, and extracts the wave number of the central sample point (step S304). More specifically, the analysis unit 40 selects the same wavenumber range as the wavenumber range of the excitation light spectrum (this is the calculation interval) in the spectrum of the scattered light, and determines the central wavenumber of the selected wavenumber range. At this time, the analysis unit 40 takes a plurality of sample points at predetermined intervals in the first calculation interval of the spectrum of the scattered light, and generates a table (hereinafter referred to as a 1 calculation interval table).

Although not shown, the analysis unit 40 also takes sample points at predetermined intervals for the spectrum of the excitation light. At this time, if the number of sample points in the spectrum of the excitation light is smaller than the number of sample points in the first calculation interval of the spectrum of the scattered light, the analysis unit 40 corresponds to the wave number of each sample point in the spectrum of the scattered light. Interpolate the sample points to the wave number. Next, the analysis unit 40 creates a table (hereinafter referred to as an excitation light table) in which wave numbers and measured values at each sample point of the excitation light spectrum are associated with each other.

Next, the analysis unit 40 calculates the covariance of the table of the first calculation interval and the table of excitation light (step S305). The following equation (1) is used to calculate the covariance. The analysis unit 40 stores the calculated covariance value in a table (hereinafter referred to as a correlation table) in association with the wave number corresponding to the central sample point of the first calculation interval. Thereby, the degree of correlation between the spectrum of scattered light and the spectrum of excitation light in the first calculation interval is calculated. Note that, unlike Raman scattered light, fluorescence generated by irradiation with excitation light does not reflect the shape of the spectrum of excitation light. Therefore, by calculating the covariance, the influence of fluorescence can be removed from the spectrum of scattered light. Further, as described above, since the degree of correlation is calculated in a fixed interval, the influence of high frequency noise and offset other than fluorescence is also reduced.

（上記式中、Ｓ_ｘｙ：共分散、ｎ：データの総数、（ｘ_ｉ，ｙ_ｉ）：ｉ番目のデータの値、Ｘ，Ｙ：ｘ，ｙの平均を示す。）

(In the above formula, S _xy : covariance, n: total number of data, (x _i , y _i ): value of the i-th data, X, Y: indicates the average of x, y.)

Next, the analysis unit 40 determines whether the calculation of covariance has been completed in a predetermined range of the spectrum of the scattered light (step S306). Here, the predetermined range refers to the analysis target range in the spectrum of scattered light. The analysis target range may differ depending on the object to be measured.

If the covariance calculation has not been completed in the predetermined range of the spectrum of the scattered light (NO in step S306), the analysis unit 40 calculates the central sample point of the previous calculation interval (here, the first calculation interval). A calculation interval whose central sample point is the sample point shifted by 1 from 1 is extracted (step S307). At this time, similar to the procedure described in step S304, the analysis unit 40 takes a plurality of sample points at predetermined intervals in the calculation interval, and creates a table (second Create a calculation interval table). Next, the analysis unit 40 calculates the covariance of the table of the second calculation interval and the table of excitation light (step S305). The analysis unit 40 repeats the loop of S305 to S307, and when the calculation of the covariance in a predetermined range is completed (YES in step S306), the analysis unit 40 calculates the degree of correlation between the spectrum of the scattered light and the spectrum of the excitation light in the predetermined range. Calculation is complete. The correlation table stores the degree of correlation at each wave number. The data stored in the correlation table is called correlation spectrum data. The analysis unit 40 stores the correlation spectrum data in a storage unit (not shown) (step S308).

As a result, in the spectrum of the scattered light, a peak (Raman peak) where the spectrum of the excitation light is shifted by a predetermined wave number is emphasized, and a peak that has no correlation with the spectrum of the excitation light is suppressed. Therefore, the degree of correlation represents the spectrum of scattered light from which the influence of noise such as fluorescence has been removed. Therefore, according to the Raman spectroscopy spectrum analysis method according to one aspect of the present disclosure, the influence of fluorescence can be easily removed from the spectrum measured by Raman spectroscopy (so-called spectrum of scattered light).

Hereinafter, the Raman spectroscopic analysis method of the present disclosure will be specifically explained using experimental examples and examples, but the present disclosure is not limited to the following experimental examples and examples.

First, Experimental Examples 1 to 4 will be explained. In the following experimental examples, the object to be measured is silicon, and the light source is a Fabry-Perot semiconductor laser.

(Experiment example 1 and experiment example 2)
First, Experimental Example 1 and Experimental Example 2 will be explained with reference to the drawings. FIG. 4 is a diagram showing the spectrum of excitation light in Experimental Example 1 and Experimental Example 2. FIG. 5 is a diagram showing spectra of scattered light in Experimental Example 1 and Experimental Example 2. FIG. 6 is a diagram showing correlation spectra in Experimental Example 1 and Experimental Example 2. In each figure, (a) shows the data of Experimental Example 1, and (b) shows the data of Experimental Example 2.

As shown in FIG. 4, in Examples 1 and 2, the excitation light spectrum was irradiated with a laser beam whose peaks had two peaks. As shown in FIG. 4(a), in Experimental Example 1, the spectrum of excitation light and the spectrum of scattered light were measured while the light source was stable. On the other hand, as shown in FIG. 4B, in Experimental Example 2, the excitation light spectrum and the scattered light spectrum were measured while the light source was unstable due to slight disturbance (for example, current amount or temperature). At this time, the width of the peak of the spectrum of the excitation light was broadened, and the shape had a small peak at the foot of the peak. Therefore, in Experimental Example 2, the peak intensity of the excitation light spectrum was lower than in Experimental Example 1. As shown in FIG. 4, the wave number range of the spectrum of the excitation light in Experimental Example 1 and Experimental Example 2 was −100 cm ⁻¹ to 100 cm ⁻¹ , respectively. This was used as one calculation interval in the correlation degree calculation below.

Each object to be measured was irradiated with excitation light having the spectral states shown in FIG. 4, and the spectrum of the scattered light was measured. As a result, in Experimental Example 1, as shown in FIG. 5A, the shape of the peak of the spectrum of the scattered light had a shape that correlated with the shape of the spectrum of the excitation light. Similarly, in Experimental Example 2, as shown in FIG. The shape of the spectrum was correlated with the shape of the spectrum. However, when the ease of detecting the peak was evaluated using the value obtained by subtracting the DC offset intensity from the peak intensity of scattered light divided by 3σ (S/N ratio), in Example 1, (Peak-DC )/3σ=5.12, and in Example 2, (Peak-DC)/3σ=4.75. In Experimental Example 2, since the peak intensity of the excitation light was lower than that in Experimental Example 1, the peak intensity of the Raman scattered light also decreased, and as a result, it is thought that the ease of detecting the peak decreased.

Subsequently, the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light was calculated according to the calculation method explained in FIG. 3, and a correlation spectrum was derived. In Experimental Example 1, as shown in FIG. 6(a), the peak intensity of the correlation spectrum is approximately 150,000, and in Experimental Example 2, as shown in FIG. 6(b), the peak intensity of the correlation spectrum is , about 130,000. However, in the correlation spectrum of Example 1, compared to the correlation spectrum of Example 2, the spectrum in the region other than the peak was not smooth. Furthermore, in the correlation spectra of Experimental Examples 1 and 2, for example, when comparing the spectra of wave numbers 550 cm ^-1 to 600 cm ^-1 , it is found that the peak detected in Example 2 is difficult to detect in Example 1 due to noise. That's what I found out. Similarly to FIG. 5, in FIG. 6, the value of (Peak-DC)/3σ was calculated, and it was 10.60 in Example 1 and 13.20 in Example 2. When these values were compared with the value of (Peak-DC)/3σ in the spectrum of the scattered light in FIG. 5, by calculating the degree of correlation, Example 1 was improved by 2.07 times, 2, the improvement was 2.78 times.

Therefore, from the results of Examples 1 and 2, even if low-quality laser light is used, the influence of fluorescence can be easily analyzed by analyzing the spectrum of scattered light based on the degree of correlation (the above correlation spectrum). It was confirmed that it could be removed easily and accurately. In addition, since the peak shape of the excitation light spectrum is more characteristic when the excitation light is distorted than when the excitation light is stable, the degree of correlation between the excitation light spectrum and the scattered light spectrum can be improved. It was found that calculations can be made with good accuracy.

(Experiment example 3 and experiment example 4)
Next, Experimental Examples 3 and 4 will be described with reference to the drawings. FIG. 7 is a diagram showing the spectrum of excitation light in Experimental Example 3 and Experimental Example 4. FIG. 8 is a diagram showing spectra of scattered light in Experimental Examples 3 and 4. FIG. 9 is a diagram showing correlation spectra in Experimental Example 3 and Experimental Example 4. In each figure, (a) shows the data of Experimental Example 3, and (b) shows the data of Experimental Example 4.

As shown in FIG. 7, in Examples 3 and 4, the tips of the peaks of the excitation light spectrum are two peaks, and the peak width is narrower than that of the laser beams used in Examples 1 and 2. , and a laser beam with a low peak intensity was irradiated. As shown in FIG. 7A, in Experimental Example 3, the spectrum of excitation light and the spectrum of scattered light were measured in a state where mode hops occurred due to slight fluctuations in the light source. At this time, since the peak of the excitation light spectrum was divided into two, the peak intensity decreased. The value obtained by subtracting the intensity of the DC offset from the intensity of the main peak was Peak-DC=114412. On the other hand, as shown in FIG. 7B, in Experimental Example 4, the spectrum of excitation light and the spectrum of scattered light were measured in a state where the light source was stable. At this time, the value obtained by subtracting the DC offset intensity from the peak intensity was Peak-DC=131159. As shown in FIG. 7, the wave number range of the spectrum of the excitation light in Experimental Example 3 and Experimental Example 4 was −100 cm ⁻¹ to 100 cm ⁻¹ , respectively. This was used as one calculation interval in the correlation degree calculation below.

Each object to be measured was irradiated with excitation light having the spectral states shown in FIG. 7, and the spectrum of the scattered light was measured. As a result, in Experimental Example 3 as well, as shown in FIG. The shape of the spectrum was correlated with the shape of the spectrum. Similarly, in Experimental Example 4, as shown in FIG. 8(b), the shape of the peak of the spectrum of the scattered light had a shape that correlated with the shape of the spectrum of the excitation light. However, when the ease of peak detection was evaluated using the value obtained by subtracting the DC offset intensity from the peak intensity of scattered light divided by 3σ (S/N ratio), in Example 3, (Peak-DC )/3σ=3.45, and in Example 4, (Peak-DC)/3σ=5.32. In Experimental Example 3, the peak intensity of the excitation light was lower than in Experimental Example 4, so the peak intensity of the Raman scattered light was also reduced, and as a result, it is thought that the ease of detecting the peak was reduced.

Subsequently, the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light was calculated according to the calculation method explained in FIG. 3, and a correlation spectrum was derived. In Experimental Example 3, as shown in FIG. 9(a), the peak intensity of the correlation spectrum is approximately 90,000, and in Experimental Example 4, as shown in FIG. 9(b), the peak intensity of the correlation spectrum is approximately 90,000. , about 120,000. Further, similarly to FIG. 8, in FIG. 9, the value of (Peak-DC)/3σ was calculated, and it was 5.27 in Experimental Example 3 and 7.28 in Experimental Example 4. Comparing these values with the value of (Peak-DC)/3σ in the spectrum of the scattered light in FIG. 4, the improvement was 1.37 times. These values were lower than those in Experimental Examples 1 and 2. In addition, in Experimental Example 3, the improvement rate was higher than in Experimental Example 4, but unlike in Experimental Examples 1 and 2, the value of (Peak-DC)/3σ of the correlation spectrum in Experimental Example 3 was It was smaller than the value of Experimental Example 4.

Therefore, from the results of Experimental Examples 3 and 4, when the peak intensity of the excitation light is lower than a predetermined value, if the excitation light is unstable, the correlation will be lower than when the excitation light is stable. I understand. Therefore, in order to obtain better analysis results, it is preferable to use excitation light whose peak intensity is equal to or higher than a predetermined value. In other words, if the peak intensity of the excitation light is lower than a predetermined value, adjust the excitation light so that the peak intensity of the excitation light is greater than or equal to the predetermined value, and re-measure the spectrum of the excitation light and the spectrum of the scattered light. Then I was able to confirm something good.

Furthermore, even if the light source (for example, a Fabry-Perot semiconductor laser) is controlled under certain conditions, it may become unstable. Therefore, it is advisable to perform the measurement multiple times and select the more reliable data from among them. In other words, it was confirmed that it is better to measure the spectrum of excitation light and the spectrum of scattered light multiple times, calculate the degree of correlation for each, and select the degree of correlation with a high peak intensity (the above-mentioned correlation spectrum).

(Example 1)
Next, Example 1 will be described. In Example 1, the object to be measured is ZnDTP (Zinc Dialkyldithiophosphate), and the light source is a Fabry-Perot semiconductor laser.

(1) Measurement of spectrum of excitation light First, the spectrum of excitation light was measured. The conditions are as follows.

Exposure conditions: 0.5 seconds x 100 times Measurement timing: Immediately before measuring the spectrum of scattered light

FIG. 10 is a diagram showing the spectrum of excitation light in Example 1. As shown in FIG. 10, the excitation light was in a state in which weak mode hops occurred on the lower wave number side (that is, on the shorter wavelength side) than the peak. The wave number range of the spectrum of the excitation light was −138.3 cm ⁻¹ to 135.5 cm ⁻¹ . The wave number range of the spectrum of this excitation light was defined as one calculation interval, and was used in the calculation of the degree of correlation below.

(2) Measurement of object to be measured and calculation of degree of correlation After measuring the spectrum of excitation light, the spectrum of scattered light from the object to be measured was measured. The conditions are as follows.

Exposure conditions: 30 seconds x 10 times Object to be measured: ZnDTP

After measuring the spectrum of the scattered light, the degree of correlation (hereinafter referred to as covariance) between the spectrum of the excitation light and the spectrum of the scattered light was calculated according to the procedure explained in FIG. One calculation interval is the wave number range of the excitation light spectrum.

FIG. 11 is a diagram showing the spectrum and correlation spectrum of scattered light in Example 1. As explained in FIG. 3, the correlation spectrum is a covariance (likelihood) graph in a predetermined range of the spectrum of scattered light. In the correlation spectrum, a peak enhancement effect was obtained by applying covariance. In other words, peaks correlated with the excitation light spectrum were emphasized, and uncorrelated noise was efficiently removed. This is clear from the scattered light spectrum and correlation spectrum shown in FIG. Therefore, it was confirmed that the S/N ratio was improved by calculating the covariance in each calculation interval of the spectrum of scattered light using the method described in FIG.

(3) Comparison with FTIR spectrum Next, the correlation spectrum of ZnDTP obtained in (2) was compared with the FTIR spectrum of ZnDTP. FIG. 12 is a diagram showing the correlation spectrum in Example 1 and the FTIR spectrum of ZnDTP.

As shown in FIG. 12, it was confirmed that the positions of many peaks in the ZnDTP correlation spectrum and FTIR spectrum generally coincided. For example, in the FTIR spectrum, the absorption of the S=P bond in the ZnDTP molecule is detected around 670 cm ⁻¹ . A peak was also detected at almost the same position in the correlation spectrum. Furthermore, in the FTIR spectrum, the absorption of the POR bond in the ZnDTP molecule is detected around 970 cm ⁻¹ . A peak was also detected at almost the same position in the correlation spectrum. Similarly, for other peaks detected in the FTIR spectrum, peaks were detected at approximately the same positions in the correlation spectrum.

From the above, it was confirmed that the degree of correlation between the spectrum of excitation light and the spectrum of scattered light could be calculated, and the spectrum of scattered light could be analyzed based on the calculated degree of correlation (the above correlation spectrum). Therefore, it can be confirmed that according to the Raman spectroscopy spectrum analysis device and the Raman spectroscopy spectrum analysis method of the present disclosure, it is possible to easily remove the influence of fluorescence from the spectrum measured by Raman spectroscopy (so-called spectrum of scattered light). Ta.

(Other embodiments)
The Raman spectroscopy spectrum analysis device and Raman spectroscopy spectrum analysis method according to one or more aspects of the present disclosure have been described above based on the above embodiments, but the present disclosure is not limited to these embodiments. It's not something you can do. Unless it deviates from the spirit of the present disclosure, one or more embodiments of the present disclosure may be modified by making various modifications to the embodiments that those skilled in the art would think of, or by combining components of different embodiments. may be included within the range.

Note that in the above embodiment, covariance is used as the calculation formula for the degree of correlation, but other correlation indexes may be used as the calculation formula. For example, it may be a product-sum coefficient, a Pearson correlation coefficient, a determination coefficient, or the like.

For example, some or all of the components included in the Raman spectroscopic spectrum analysis apparatus in the above embodiment may be configured from one system LSI (Large Scale Integration). For example, a Raman spectroscopic spectrum analysis device may be configured from a system LSI having a light source, a spectroscopic section, and an analysis section. Note that the system LSI does not need to include a light source.

A system LSI is an ultra-multifunctional LSI manufactured by integrating multiple components on a single chip, and specifically includes a microprocessor, ROM (Read Only Memory), RAM (Random Access Memory), etc. A computer system that includes: A computer program is stored in the ROM. The system LSI achieves its functions by the microprocessor operating according to a computer program.

Note that although it is referred to as a system LSI here, it may also be called an IC, LSI, super LSI, or ultra LSI depending on the degree of integration. Moreover, the method of circuit integration is not limited to LSI, and may be implemented using a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used.

Furthermore, if an integrated circuit technology that replaces LSI emerges due to advancements in semiconductor technology or other derived technology, then of course the functional blocks may be integrated using that technology. Possibilities include the application of biotechnology.

Moreover, one aspect of the present disclosure may be not only such a Raman spectroscopy spectrum analysis apparatus but also a Raman spectroscopy spectrum analysis method that uses a characteristic component included in the apparatus as a step. Further, one aspect of the present disclosure may be a computer program that causes a computer to execute each characteristic step included in the Raman spectroscopy spectrum analysis method. Further, one aspect of the present disclosure may be a computer-readable non-transitory recording medium on which such a computer program is recorded.

[Application example]
FIG. 13 is a diagram illustrating an example of a Raman spectroscopy spectrum analysis system 500 including a Raman spectroscopy spectrum analysis device 100a according to the present disclosure. The Raman spectroscopy spectrum analysis system 500 is, for example, a system that monitors the state of a consumable member included in the mechanical device 200 and notifies the user of the mechanical device 200 of the state of deterioration of the consumable member.

The mechanical equipment 200 includes, for example, various types of large or small mechanical equipment installed inside or outside factories, offices, public facilities, and residences, construction equipment that operates outdoors, trucks, buses, passenger cars, motorcycles, ships, aircraft, and trains. , industrial vehicles, construction vehicles, and their equipment, such as engines, transmissions, and operating devices.

Further, the consumable members included in the mechanical device 200 are used repeatedly within the mechanical device 200, and are replaced periodically, for example. The consumable member is, for example, oil that functions as a lubricating medium, cooling medium, or power transmission medium for the mechanical device 200, or a filter that filters oil. Since such consumable members are arranged inside the mechanical device 200, it is not easy for the user of the mechanical device 200 to check the condition of the consumables. Therefore, by incorporating the Raman spectroscopy spectrum analyzer 100a into the mechanical device 200, it becomes possible to measure the condition of the consumable member in-line.

For example, as shown in FIG. 13, in a Raman spectroscopic spectrum analysis apparatus 100a, a light source 10a and a spectrometer 20a are built into a mechanical device 200, and a processor 30a is installed in a computer. The processor 30a is not limited to a computer, and may be installed in a terminal such as a smartphone, a mobile phone, a tablet terminal, a wearable terminal, or a computer installed in the mechanical device 200. Spectrometer 20a and processor 30a can communicate with each other. For example, the user may input operation information via an input unit (not shown) such as a touch panel, keyboard, mouse, or microphone, and transmit it to the light source 10a, spectrometer 20a, or server 300. Further, the user may select necessary information and have it presented on a presentation unit such as a monitor or speaker. Thereby, the user can obtain information such as the condition of the consumable member, the timing of replacing the consumable member, and troubles that may occur in the mechanical device 200. Note that the input section and the display section only need to be connected to the processor 30a, and may be provided in a device other than the device in which the processor 30a is mounted. Further, the number of input units and presentation units is not limited to one each, and a plurality of input units and presentation units may be connectable to the processor 30a. The device equipped with the processor 30a is connected to the server 300 via the network 400, transmits the measurement results of consumable parts to the server 300, and analyzes the results using an information processing program stored in a database located on the server 300. You may also obtain the analyzed results. The processor 30a may cause the presentation unit to present the acquired analysis results to inform the user.

In the present disclosure, in order to analyze the spectrum of scattered light based on the degree of correlation between the spectrum of excitation light and the spectrum of scattered light from the object to be measured, the influence of fluorescence is determined from the spectrum of scattered light measured by Raman spectroscopy. Can be easily removed. This effect can be achieved regardless of the spectral quality of the excitation light. Therefore, it is possible to use a low-quality laser that cannot conventionally be used as a light source for Raman spectroscopy. Therefore, according to the present disclosure, it is possible to provide a device that has a simple configuration and is miniaturized, for example, without using high-definition equipment. In addition, the Raman spectrometer spectrometer of the present disclosure is not limited to analytical use, but can also be applied to industrial use as in this application example, and can be used simply and quickly in various fields such as cosmetics, medicine, or food. The object to be measured can be measured with high accuracy.

According to the present disclosure, since the influence of fluorescence can be easily and efficiently removed from a spectrum measured by Raman spectroscopy, it is possible to analyze a Raman spectrum with high accuracy. Furthermore, since a general-purpose laser can be used, it is possible to provide a simple and compact analyzer without using any special optical system. Therefore, it can be used not only as an analysis device but also as an in-line analysis device by incorporating it into a mechanical device.

DESCRIPTION OF SYMBOLS 10, 10a Light source 20, 20a Spectrometer 22 Measurement part 30, 30a Processor 40 Analysis part 50 Control part 100, 100a Raman spectroscopy spectrum analysis device 200 Mechanical device 300 Server 400 Network 500 Raman spectroscopy spectrum analysis system

Claims (8)

a light source that irradiates an object to be measured with excitation light;
a spectrometer that measures the spectrum of the light by dividing the light;
a processor connected to the spectrometer;
Equipped with
The spectrometer includes a measurement unit that acquires the spectrum of the excitation light irradiated from the light source and measures the spectrum of scattered light scattered from the object to be measured by the irradiation of the excitation light,
The processor includes an analysis unit that calculates a degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, and analyzes the spectrum of the scattered light based on the calculated degree of correlation.
Raman spectroscopy spectrum analyzer. The light source emits light having a plurality of emission spectrum peaks with different emission center wavelengths,
The Raman spectroscopic spectrum analyzer according to claim 1. The measurement unit acquires the spectrum of the excitation light by measuring the spectrum of the scattered light including the wavelength band of the excitation light during, before, or after measurement of the spectrum of the excitation light.
The Raman spectroscopic spectrum analysis device according to claim 1 or 2. The analysis unit determines the quality of the spectrum of the excitation light at least prior to calculating the correlation degree,
The processor further includes a control unit that causes the measurement unit to acquire the spectrum of the excitation light and measure the spectrum of the scattered light when it is determined that the quality of the excitation light is lower than a predetermined quality. Prepare,
The analysis unit analyzes the spectrum of the scattered light based on the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, which is obtained by causing the measurement unit to execute the analysis unit.
The Raman spectroscopic spectrum analysis device according to any one of claims 1 to 3. The measurement unit acquires the spectrum of the excitation light and measures the spectrum of the scattered light multiple times,
The analysis unit calculates the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, selects a degree of correlation with a high peak intensity from among the plurality of calculated degrees of correlation, and calculates the degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light. analyzing the spectrum of the scattered light based on the degree of correlation;
The Raman spectroscopic spectrum analysis device according to any one of claims 1 to 4. The light source includes a light emitting element, and is based on at least one parameter of the temperature of the light emitting element, the amount of current conducted to the light emitting element, the frequency of the excitation light, and the mounting position of the external resonator with respect to the light source. , changing the spectrum of the excitation light by changing the oscillation state of the excitation light emitted from the light emitting element;
The Raman spectroscopic spectrum analysis device according to any one of claims 1 to 5. The analysis unit analyzes a plurality of types of components contained in the object to be measured in analyzing the spectrum of the scattered light.
The Raman spectroscopic spectrum analyzer according to any one of claims 1 to 6. an irradiation step of irradiating the object to be measured with excitation light;
a measuring step of acquiring a spectrum of the excitation light irradiated to the object to be measured, and measuring a spectrum of scattered light scattered from the object to be measured by the irradiation of the excitation light;
an analysis step of calculating a degree of correlation between the spectrum of the excitation light and the spectrum of the scattered light, and analyzing the spectrum of the scattered light based on the calculated degree of correlation;
including,
Raman spectroscopy spectrum analysis method.

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