JP2022041186A - Temperature measurement method by raman scattered light and raman scattered light analyzer - Google Patents

Abstract

To provide a method for measuring the temperature of a sample utilizing Raman scattered light, in which the temperature at a prescribed point of the sample being irradiated with excitation light can be measured easily in a short time with high accuracy.SOLUTION: A provisional temperature at a prescribed point of a sample and detection light intensity which is detected Raman scattered light intensity on anti-Stokes side are applied to a theoretical formula that indicates a relationship between Raman scattered light intensity on Stokes side and Raman scattered light intensity on anti-Stokes side and the sample temperature, and theoretical light intensity that is Raman scattered light intensity on Stokes side at the provisional temperature is thereby calculated. The provisional temperature of the sample when a correlation between theoretical light intensity on the Stokes side and detected Raman scattered light intensity on Stokes side is larger than a maximum or prescribed threshold is defined as a measured temperature.SELECTED DRAWING: Figure 6

Description

The present invention relates to a temperature measuring method or the like using Raman scattered light.

Conventionally, a method of analyzing a sample by using Raman scattered light generated when the sample is irradiated with excitation light (hereinafter referred to as Raman spectroscopy) is known. Raman scattered light is scattered light with a wavelength (wave number) different from that of the excitation light, and appears in the band before and after the peak wavelength of the excitation light.

When analyzing a sample by this Raman spectroscopy, the temperature of the sample rises too much due to the irradiation of the excitation light, and the sample becomes overheated, which may cause degeneration, deterioration, etc. of the sample, resulting in a defect in the analysis.

This can be prevented by monitoring the temperature of the sample. For example, Patent Document 1 describes a configuration in which when an analysis obstruction event occurs in a Raman spectroscopic analyzer, the obstruction event is displayed on a measurement screen and help information prompting the countermeasure is displayed. ing. The above configuration may be applied with the superheated state as an analysis obstruction event.
For that purpose, it is necessary to detect the sample temperature.

However, if a temperature sensor for measuring the sample temperature is separately attached, there is a risk that the size will increase, the structure will become complicated, or the price will increase. Furthermore, it is also difficult to measure the temperature of the pinpoint region irradiated with the excitation light in the sample.

The intensity of Raman scattered light on the Stokes side and the anti-Stokes side depends on the sample temperature. The formula for obtaining the sample temperature from them is known, and a method for measuring the temperature of the sample using this is described in Patent Document 2. Therefore, by utilizing this, the sample can be prepared without providing a dedicated temperature sensor. It is also possible to measure the temperature. However, with this method, it is difficult to measure the accurate temperature of the sample in a short time.

This is because, in this method, in order to ensure the accuracy of temperature measurement, a different value offset is set for each wave number of each wave number of the measured raw Raman spectrum, that is, baseline correction is performed. This is because the calculation load for obtaining the offset value is extremely large and it takes time.

Japanese Patent No. 5385856 Japanese Unexamined Patent Publication No. 11-337420

The present invention has been made in view of the above-mentioned problems, and in a method for measuring a sample temperature using Raman scattered light, the temperature of the sample at a predetermined portion irradiated with excitation light can be easily and accurately measured. Its main purpose is to enable measurement in a short time and to provide a Raman spectroscopic analyzer using the temperature measuring method.

That is, the temperature measuring method according to the present invention is as follows.

In Raman scattered light generated by irradiating a predetermined part of a sample with excitation light, the Stokes side light intensity, which is the light intensity obtained by shifting the excitation light to the Stokes side and the anti-Stokes side by a predetermined shift wave number, respectively. And the Raman scattered light intensity detection step to detect the anti-Stokes side light intensity,
A temperature assumption step that assumes a plurality of temperatures of the predetermined part, and
In the theoretical relationship between the intensity of each Raman scattered light on the Stokes side and the anti-Stokes side and the sample temperature, the detected light intensity on each side detected in the Raman scattered light intensity detection step, and the temperature assumption step. A correlation calculation step for obtaining the correlation with the assumed relationship, which is the relationship with the assumed assumed temperature, for each assumed temperature.
It is characterized by having a temperature specifying step for specifying the measurement temperature of the predetermined portion based on the correlation at each assumed temperature calculated in the correlation calculation step.

More specifically, the temperature measuring method according to the present invention is:
In the Raman scattered light generated by irradiating a predetermined part of the sample with excitation light, the Raman scattered light intensity is the wave number shifted from the wave number of the excitation light to the Stokes side and the anti-Stokes side by a predetermined shift wave number, respectively. Raman scattered light intensity detection step to detect light intensity and anti-Stokes side light intensity,
A theoretical formula storage step for storing a theoretical formula showing the theoretical relationship between the Raman scattered light intensity on the Stokes side and the anti-Stokes side and the sample temperature,
A temperature assumption step that assumes a plurality of temperatures of the predetermined part, and
By applying the assumed temperature assumed in the temperature assumption step and the Raman scattered light intensity on either side (hereinafter referred to as the detected light intensity) detected in the Raman scattered light intensity detection step to the theoretical formula. A theoretical light intensity calculation step for calculating the theoretical Raman scattered light intensity on the other side (hereinafter referred to as theoretical light intensity), and
A correlation calculation step for obtaining the correlation of the detected light intensity on the other side with respect to the theoretical light intensity on the other side for each of the plurality of assumed temperatures.
It is characterized by having a temperature specifying step for specifying the measurement temperature of the predetermined portion based on the correlation at each assumed temperature obtained in the correlation calculation step.

In the above-mentioned invention, the temperature is not obtained atypically from the Raman scattered light intensity, but the temperature is assumed first, and the Raman scattered light intensity derived from the assumed temperature is close to the measured Raman scattered light intensity. Since the sample temperature is measured in a recursive manner, using the assumed temperature at that time as the measurement temperature, it is directly applied to the intensity spectrum data of Raman scattered light that has not been subjected to baseline correction, that is, has not been pretreated. can.

Therefore, operations such as baseline correction, which have a large load and remain uncertain, are not required, and continuous and accurate temperature measurement can be performed in a short time. Then, by using this temperature measurement result, for example, the possibility of temperature damage to the sample can be determined in real time. Of course, since the temperature is measured using Raman scattered light, it is possible to obtain the premise effect that the temperature of the sample at the site irradiated with the excitation light can be measured pinpointly.

Further, since no pretreatment is required, the temperature can be measured regardless of the Raman spectral shape, and the temperature can be measured without specifying the Raman band, there is no dependence on the composition of the sample or the like. This leads to the effect that, for example, temperature mapping data of each part of the sample having a non-uniform composition can be easily obtained. This is because even if the element or composition changes during the mapping process and the band changes, the effect on temperature measurement is extremely small. The effect becomes remarkable when the present invention is applied to a Raman microscope, which is one of the Raman spectroscopic analyzers.

As a specific embodiment in the temperature specifying step, it can be mentioned that the assumed temperature when the correlation becomes the highest or becomes higher than a predetermined threshold value is set as the measured temperature of the predetermined portion.

In order to realize more accurate temperature measurement, it is preferable to correlate the multipoint data, for example, the Raman spectrum. This is because it is less susceptible to intensity fluctuations due to local noise in the Raman spectrum.

For that purpose, in the Raman scattered light intensity detection step, the Stokes side detected light intensity and the anti-Stokes side detected light intensity at a plurality of different shift wave numbers are detected, respectively, and in the theoretical light intensity calculation step, the Raman scattering A plurality of theoretical light intensities of the other side corresponding to each detected light intensity of the other side detected in the light intensity detection step are calculated, and in the correlation calculation step, a plurality of other sides calculated in the theoretical light intensity calculation step. It is preferable to obtain the correlation between each theoretical light intensity of the above and the detected light intensity on the other side of the plurality of light detected in the Raman scattered light intensity detection step.
On the other hand, in this method, the intensity of Raman scattered light (detection light intensity) at a wave number shifted by the same shift wave number to each of the Stokes side and the anti-Stokes side from the wave number of the excitation light is used. However, depending on the spectroscope, it is not possible to conveniently disperse the wave number shifted by the same shift wave number from the wave number of the excitation light.
Therefore, in the Raman scattered light intensity detection step, the Raman scattered light intensity at a plurality of waves detected by the light detector via the spectroscope is interpolated, and the spectral data on the Stokes side and the anti-Stokes side that are continuous with respect to the wave number are calculated. However, it is preferable to calculate the Stokes-side detected light intensity and the anti-Stokes-side detected light intensity at a plurality of different shift wave numbers from these spectral data.

Further, as an embodiment in which the effect of the present invention is particularly remarkable, there is an analysis step of analyzing the predetermined portion of the sample based on the Raman scattered light in the Raman spectroscopic analysis method using the temperature measurement method. A Raman spectroscopic analysis method characterized by having a display step for displaying the measured temperature at the same time on a display screen displaying the analysis process or the analysis result in the analysis step can be mentioned.

In order to be able to grasp the time change of the sample temperature during one sample analysis, the temperature is measured a plurality of times during the analysis of a predetermined part in the analysis step, and in the display step, each time the temperature is measured, the temperature is measured. It is preferable that the measured temperature is updated and displayed.

Further, the present invention is based on a light source that irradiates a predetermined portion of a sample with excitation light, a light detector that detects Raman scattered light generated by irradiation of the excitation light, and Raman scattered light detected by the light detector. A temperature measuring unit for measuring the temperature of the predetermined portion is provided.
The temperature measuring unit
Based on the Raman scattered light detected by the light detector, the Stokes side Raman scattered light is the intensity of the Raman scattered light at the wave number shifted from the wave number of the excitation light to the Stokes side and the anti-Stokes side by the same shift wave number. A Raman scattered light intensity detector that detects the intensity and the Raman scattered light intensity on the anti-Stokes side,
A theoretical formula storage unit that stores in advance a theoretical formula showing the relationship between the Raman scattered light intensity on the Stokes side and the anti-Stokes side and the sample temperature.
A temperature assumption part that assumes a plurality of temperatures of the predetermined part, and a temperature assumption part.
By applying the assumed temperature assumed by the temperature assumption unit and the Raman scattered light intensity on one side (hereinafter referred to as the detected light intensity) detected by the Raman scattered light intensity detection unit to the theoretical formula, the other side is applied. The theoretical light intensity calculation unit that calculates the theoretical Raman scattered light intensity (hereinafter referred to as the theoretical light intensity) of
A correlation calculation unit for obtaining the correlation of the detected light intensity on the other side with respect to the theoretical light intensity on the other side for each of the plurality of assumed temperatures.
The temperature measuring device may be characterized in that it is provided with a temperature specifying unit that specifies the measured temperature of the predetermined portion based on the correlation at each assumed temperature obtained by the correlation calculation unit.

Further, as an embodiment in which the effect of the present invention is particularly remarkable, an analysis unit that analyzes the predetermined portion of the sample based on the Raman scattered light, an analysis process or analysis result in the analysis unit, and the measurement temperature are used. Can be mentioned as a Raman spectroscopic analyzer equipped with a display unit that simultaneously displays the above on the same screen.

Further, the present invention is a program applied to a Raman spectroscopic analyzer including a light source that irradiates a predetermined portion of a sample with excitation light and a light detector that detects Raman scattered light generated by irradiation of the excitation light. hand,
Based on the Raman scattered light detected by the light detector, the shift wave number at the wave number shifted from the wave number of the excitation light to the Stokes side and the anti-Stokes side by a predetermined shift wave number. A Raman scattered light intensity detector that detects a certain Stokes side light intensity and anti-Stokes side light intensity,
A temperature assumption part that assumes a plurality of temperatures of the predetermined part, and a temperature assumption part.
The theoretical relationship between the intensity of each Raman scattered light on the Stokes side and the anti-Stokes side and the sample temperature, the detected light intensity on each side detected in the Raman scattered light intensity detection step, and the temperature assumption step. A correlation calculation unit that obtains the correlation with the assumed relationship, which is the relationship with the assumed temperature assumed in, for each assumed temperature.
The program may be characterized in that it exerts a function as a temperature specifying unit that specifies the measured temperature of the predetermined portion based on the correlation at each assumed temperature calculated in the correlation calculation step.

According to the present invention, as described above, the temperature of the sample at a predetermined site irradiated with the excitation light can be easily and accurately measured in a short time.

It is an overall schematic diagram of the Raman spectroscopic analyzer in one Embodiment of this invention. It is a flowchart which shows the operation of the temperature measuring part (temperature measuring apparatus) in the same embodiment. It is an analysis screen display example of the Raman spectroscopic analyzer in the same embodiment. Correlation showing the correlation between the anti-Stokes side assumed Raman spectrum (anti-Stokes side assumed light intensity) and the anti-Stokes side detected Raman spectrum (Stokes side detected light intensity) when the temperature is specified in the temperature measurement in the same embodiment. It is a graph. In the temperature measurement in the same embodiment, the spectrum showing the anti-Stokes side assumed Raman spectrum (anti-Stokes side assumed light intensity) and the anti-Stokes side detected Raman spectrum (Stokes side detected light intensity) superimposed when the temperature is specified. It is a figure. It is a flowchart of the manual temperature measurement method in another embodiment of this invention. It is an analysis screen display example of the Raman spectroscopic analyzer in still another embodiment of this invention. It is an example of temperature display of the Raman spectrophotometer in still another embodiment of this invention.

Hereinafter, the Raman spectroscopic analyzer according to the embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic block diagram showing the overall configuration of the Raman spectroscopic analyzer 100 of the present embodiment.
In this figure, reference numeral 1 indicates a light source for irradiating the sample W with excitation light. Here, a laser light source that emits a monochromatic laser light is used as the light source 1, but the light source is not limited to this.

Reference numeral 2 indicates a spectroscope that disperses the Raman scattered light generated by the irradiation of the excitation light. Here, a grating is used as a spectroscope, but the present invention is not limited to this.

Reference numeral 3 indicates an optical detector that detects light of each wavelength dispersed by the spectroscope and outputs a Raman detection signal having a value corresponding to the detected light intensity of each wavelength. The photodetector 3 is, for example, a signal that generates the Raman detection signal by subjecting an optical sensor such as a CCD or a photomultiplier tube and an output signal of the optical sensor to, for example, impedance conversion processing or digitization processing. It is equipped with a converter.

Reference numeral 4 indicates an information processing apparatus that receives a Raman detection signal output from the photodetector 3 and performs arithmetic processing on the signal to analyze the sample. The information processing device 4 is a so-called computer having a CPU, a memory, an I / O port, and the like, and the CPU and peripheral devices cooperate with each other according to a program stored in the memory in advance.
(1) Receiving unit 41 that receives the Raman detection signal for each wavelength.
(2) The value of each of these Raman detection signals, that is, the light intensity for each wavelength is interpolated to generate substantially continuous Raman spectrum data (hereinafter, also referred to as the original Raman spectrum) with respect to the wavelength (wave number). Further, the preprocessing unit 42, which applies baseline correction or the like to the original Raman spectrum data to generate secondary Raman spectrum data that can be used for analysis.
(3) Sample analysis unit 43 that analyzes the physical characteristics of the sample based on the secondary Raman spectrum data.
(4) Output unit 44 that outputs the analysis result data by the sample analysis unit to a display, a file, or the like.
It exerts its function as such.
As the interpolation method described in (2), for example, a method of taking a weighted average of the data of the latest two points can be mentioned.

As shown in FIG. 1, the Raman spectroscopic analyzer 100 according to the present embodiment has a temperature measuring unit 45 (temperature within the range of the patent claim) for measuring the temperature at a predetermined portion of the sample W irradiated with the excitation light. It is equipped with a measuring device).

The temperature measuring unit 45 measures the sample temperature during analysis in real time by using the Raman detection signal used for sample analysis, and is specifically realized by the program of the information processing apparatus 4. To.
Therefore, the details of the temperature measuring unit 45 will be described below with the explanation of the temperature measuring method which is the operation thereof.

As shown in FIG. 2, first, the temperature measuring unit 45 determines whether or not the sample W is irradiated with the excitation light to start the analysis (step S1), and if the analysis is in progress, the pretreatment unit 45. The original Raman spectrum data generated in 42 is acquired (step S2). As described above, this original Raman spectrum data is simply formed by interpolating the discrete Raman detection signal values for the wavenumber so as to have continuous values for the wavenumber, and the Raman detection signal value itself is used. It can be said to be spectral data showing the raw intensity of Raman scattered light for each wave number without performing baseline correction or the like to change it.

Next, the temperature measuring unit 45 refers to the original Raman spectrum data, and Raman scattering at the wave number (ω _o + ω _R ) shifted from the wave number ω _o of the excitation light to the Stokes side by a predetermined shift wave number ω _r . Raman scattered light intensity (hereinafter, also referred to as Stokes side detection light intensity IS) and Raman scattered light intensity (hereinafter, also referred to as Stokes side detection light intensity IS) and wave number (ω _{o --ω R} ) shifted from the excitation light to the anti-Stokes side by the shift wave number ω _R. Anti-Stokes side detection light intensity I _AS (also called) is acquired.

The temperature measuring unit 45 performs this operation for n different predetermined shift wavenumbers ω _{R (1)} to ω _{R (n)} , and the Stokes side detected light intensities _{IS (1)} to _{IS (n)} and anti. The Stokes side detection light intensities I _{AS (1)} to I _{AS (n)} are acquired and stored in a predetermined area of the memory (step S3). The Stokes side detected light intensities I _{S (1)} to I _{S (n)} and the anti-Stokes side detected light intensities I _{AS (1)} to I _{AS (n)} were detected on the so-called Stokes side and the anti-Stokes side. Raman spectrum data.

The range of shift wavenumbers ω _{R (1)} to ω _{R (n)} is set as wide as possible so as to cover at least a plurality of Raman peaks. Further, n is set to be as large as possible and the shift wavenumber interval is made as small as possible. The range and interval of the shift wavenumber are appropriately determined by the trade-off between the accuracy of the temperature measurement and the calculation time of the temperature measurement.

Note that this step S3 corresponds to the Raman scattered light intensity detection step in the claims, and the functional unit on the program that realizes the Raman scattered light intensity detection step is the Raman scattered light intensity detection unit in the claims. Corresponds to.

On the other hand, a theoretical formula storage unit is set in a predetermined area of the memory. As shown in the following formula (Equation 1), the theoretical formula storage unit stores in advance a theoretical formula showing the relationship between the Raman scattered light intensity on the Stokes side and the anti-Stokes side and the sample temperature.

Here, ω _o is the absolute wave number of the excitation light (laser light), ω _R is the Raman shift wave number, h is Planck's constant, c is the light velocity, k _B is the Boltzmann constant, and T is the absolute temperature.
It should be noted that this theoretical formula includes a formula equivalent to (Equation 1) and also includes a table format in which numerical values are listed.

Next, the temperature measuring unit 45 assumes a temperature T of a predetermined portion of the sample W (step S4). Here, the assumed temperature T is stored in the memory in advance and is configured to be acquired by the temperature measuring unit 45, but a value instructed by operator input or communication may be used as the assumed temperature. do not have.

Note that this step S4 and step S8 described later correspond to the temperature assumption step in the claims, and the functional part in the program that realizes the temperature assumption step corresponds to the temperature assumption part in the claims.

Next, on the assumption that the sample temperature is the assumed temperature T, the temperature measuring unit 45 applies the anti-Stokes side detected light intensities I _{AS (1)} to I _{AS (n)} at each shift wavenumber to the above equation (number). Substituting into 1), the Stokes side light intensities _{IS (1)} to _{IS (n)} at each shift wave number at the assumed temperature T are calculated (step S5). In the following, in order to distinguish the calculated Stokes side light intensities I _{S (1)} to I _{S (n)} from the Stokes side detection light intensities I _{S (1)} to I _{S (n)} , the Stokes side theoretical light Intensity I _{'S (1)} to I _{'S (n)} .

Note that this step S5 corresponds to the theoretical light intensity calculation step in the claims, and the functional unit on the program that realizes the theoretical light intensity calculation step corresponds to the theoretical light intensity calculation unit in the claims. ..

Next, the temperature measuring unit 45 compares the Stokes-side detected light intensities I _{S (1)} to _{IS (n)} with the Stokes-side theoretical light intensities I _{'S (1)} to I _{'S (n)} , respectively. Then, the correlation is calculated (step S6). Here, the correlation coefficient is used to determine the correlation, but the residual sum of squares or the coefficient of determination may be used. Specifically, for example, for each shift wave number ω _{R (i)} (i is an integer of 1 to n), the Stokes-side detected light intensity I _{S (i)} and the Stokes-side theoretical light intensity I _{'S (i)} are obtained. The comparison is performed, the correlation coefficient is obtained from the comparison result, and the correlation coefficient is set as the correlation value X and stored in a predetermined area of the memory. The correlation value (correlation coefficient) X takes a value between -1 and 1, and when it is 1, the correlation is the highest (strongest). Since the method of calculating this correlation coefficient is known, the description thereof will be omitted.

This step S6 corresponds to the correlation calculation step in the claims, and the functional unit on the program that realizes the correlation calculation step corresponds to the correlation calculation unit in the claims.

Next, the temperature measuring unit 45 determines whether or not the correlation value is maximized (step S7). Here, a determined value that is the square of the correlation value is used. Since this determined value has a maximum value, it is determined that the correlation value is the maximum when the maximum value is reached. More specifically, it is determined that the correlation value is the maximum when the rate of change between the determined value at the previous assumed temperature and the determined value at the current assumed temperature changes from + to − or from − to +.
If it is determined that the temperature is not the maximum, the assumed temperature is changed (step S8), and the process returns to step S5. As for the method of changing the assumed temperature, it may be increased or decreased at regular intervals or irregular intervals. For example, the change width and change direction of the assumed temperature should be changed each time according to the change tendency of the correlation value. You may do it.

When it is determined to be the maximum, the temperature measuring unit 45 sets the assumed temperature T at that time as the measurement temperature, and sets the measurement temperature data indicating the measurement temperature as the measurement time and the position data indicating the predetermined measurement site of the sample W in a memory. Log to. Further, the temperature measuring unit 45 outputs the measured temperature data via the output unit 44, and as shown in FIG. 3, the measured temperature indicated by the measured temperature data is displayed in real time on the Raman analysis display screen. Display as a numerical value or a graph with (step S9).

FIG. 4 shows an example of a correlation graph when the temperature is specified as described above. Further, FIG. 5 shows the detected Raman spectral data (Stokes side detected light intensity _{IS (1)} to _{IS (n)} ) and the theoretical Raman spectral data (Stokes side theoretical light) when the temperature is specified. The intensities I _{'S (1)} to I _{'S (n)} ) are shown on the same graph. In FIG. 5, the solid line represented by Stokes shows the spectrum by the Stokes-side detected light intensities _{IS (1)} to _{IS (n)} , and the alternate long and short dash line shown by Anti Stokes Corr is the Stokes-side theoretical light intensity. The spectra by I _{'S (1)} to I _{'S (n)} are shown.

From these FIGS. 4 and 5, it can be seen that the high correlation and the degree of agreement can be grasped, and that the temperature measurement is effectively performed.

Next, the temperature measuring unit 45 returns to step S1, and if the analysis of the predetermined portion is completed, the temperature measuring unit 45 is in a standby state until the analysis of another portion of the sample W or another sample W is started, and the analysis is still completed. If not, that is, if the laser beam is applied to the predetermined portion, the temperature measurement of the predetermined portion is started again. Then, when the measurement is completed, the measured temperature is additionally recorded in the memory by pairing with the measurement time and the position data indicating the predetermined part of the sample W, and the display on the Raman analysis display screen is updated.

However, in such a case, since the temperature is measured directly from the Raman spectrum data that has not been subjected to baseline correction, that is, that has not been preprocessed, the load such as the baseline correction is performed. It eliminates the need for large and uncertain calculations, and enables continuous and accurate temperature measurement in a short time. Using this temperature measurement result, for example, the possibility of temperature damage to the sample can be determined in real time. Moreover, since the temperature is measured using Raman scattered light, the temperature of the sample at the site irradiated with the excitation light can be measured pinpointly.

Further, since no pretreatment is required and the temperature can be measured regardless of the Raman spectrum shape and Raman band, there is no dependence on the composition of the sample and the like. This leads to the effect that, for example, temperature mapping data of each part of the sample whose composition is not uniform can be easily obtained. This is because even if the element or composition changes during the mapping process and the band changes, the effect on temperature measurement is extremely small.

Further, in the present embodiment, since the temperature is measured from the correlation of n multipoint data, in other words, the correlation between the spectral shapes, the temperature is less likely to be affected by the intensity fluctuation due to the local noise of the Raman spectrum, and the measurement is performed. Accuracy can be guaranteed.
Further, since the measured temperature is recorded as a pair with the measurement time and the measurement site, not only the temperature verification at the same time as the analysis but also the temperature verification by the log recording can be performed after the sample analysis.

In the present embodiment, the intensity of Raman scattered light (detection light intensity) at a wave number shifted by the same shift wave number to each of the Stokes side and the anti-Stokes side from the wave number of the excitation light is used. However, it is practically extremely difficult to use a spectroscope to separate the wave number of the excitation light into a wave number shifted by the same shift wave number, even if it is theoretically possible.
Therefore, in the present embodiment, spectral data on the Stokes side and anti-Stokes side that are substantially continuous with respect to the wave number are calculated by interpolation, and the Stokes side detected light intensity and the anti-Stokes side at a plurality of different shift wave numbers are calculated from these spectral data. The detected light intensity is calculated respectively. Since this interpolation does not impose a large computational load, it is possible to measure the temperature with high accuracy while using a general spectroscope used for Raman spectroscopy.

The present invention is not limited to the above embodiment.
For example, in the above embodiment, the Stokes side theoretical light intensity is calculated and the sample temperature is measured based on the correlation between this and the Stokes side detected light intensity, but the anti-Stokes side theoretical light intensity is calculated and this and Anti-Stokes. The sample temperature may be measured based on the correlation with the side detection light intensity.

The sample temperature may be calculated ex post facto from the Raman spectrum data (specifically, the original Raman spectrum data) measured and acquired in advance. At that time, the temperature can be calculated manually. For reference, FIG. 6 shows a flowchart in the case of manual calculation. In this way, it becomes possible to verify the temperature of the data acquired in the past by Raman spectroscopy.

この式（数２）では左辺がストークス側光強度とアンチストークス側光強度との比になっている。 For example, the theoretical formula can be expressed as the following formula (Equation 2) obtained by equivalent conversion of the formula (Equation 1).

In this equation (Equation 2), the left side is the ratio of the Stokes side light intensity and the anti-Stokes side light intensity.

Therefore, the assumed temperature T is substituted into the right-hand side of the equation (Equation 2) to calculate the right-hand side value, while the detected Stokes-side detected light intensity and the anti-Stokes-side detected light intensity are substituted into the left-hand side of the equation (Equation 2). The lvalue is calculated, and the assumed temperature is changed one after another so that the rvalue approaches the lvalue, that is, the correlation becomes high, and the correlation becomes equal to or higher than a predetermined threshold as in the above embodiment. The assumed temperature may be the measured temperature.

In short, the correlation of the relationship expressed by the above theoretical formula with respect to the relationship between the assumed temperature and the Stokes-side detected light intensity and the anti-Stokes-side detected light intensity is obtained, and the correlation becomes the highest or a predetermined threshold value. The measured temperature may be the assumed temperature when the temperature exceeds. The above-described embodiment also performs temperature measurement included in this concept.

The theoretical formulas 1 and 2 use a wavenumber cubed formula, but this is a case where a photon count sensor such as a CCD is used as the optical sensor. For example, when an energy-based optical sensor such as a radiator is used, as a theoretical formula, the cube term of the equation 1 or 2 becomes a fourth term as in the equation 3 below.

In the above embodiment, the assumed temperature is changed one after another starting from the initial value, but the change range and / or the change width of the assumed temperature is determined from the beginning, and each theory at a plurality of predetermined assumed temperatures is determined. The light intensity may be calculated, these may be compared with the detected light intensity, and the hypothetical temperature having the highest correlation may be used as the measurement temperature.
Although the accuracy of temperature measurement may be slightly reduced, the assumed temperature when the correlation value exceeds a predetermined threshold value may be used as the measured temperature.

The format of the temperature display can also be modified in various ways. For example, in the above embodiment, the measured temperature is numerically displayed and updated to the latest value one after another, but for example, it is updated only when the measured temperature exceeds the previous measured temperature, that is, only the maximum value of the measurement is displayed. Alternatively, a graph may be displayed in which the measurement time is on the horizontal axis and the measurement temperature is on the vertical axis instead of the numerical values.

For example, in the case of a micro-Raman spectroscopic analyzer that maps and analyzes a sample, as shown in FIG. 7, for each analysis site of the sample displayed on the screen, for example, when an analysis cursor is applied, the measured temperature at that site is measured. You may make it displayed. Further, FIG. 8 shows an example of a screen in which only the temperature of the sample is displayed in different colors.
In addition, various modifications and combinations of embodiments may be made as long as it does not contradict the gist of the present invention.

100 ... Raman spectroscopic analyzer 45 ... Temperature measuring unit (temperature measuring device)
W ... Sample

Claims (11)

In Raman scattered light generated by irradiating a predetermined part of a sample with excitation light, the shift wave number on the Stokes side and the anti-Stokes side is the number of waves shifted from the wave number of the excitation light to the Stokes side and the anti-Stokes side by a predetermined shift wave number, respectively. The Raman scattered light intensity detection step for detecting the Stokes side light intensity and the anti-Stokes side light intensity, which are the light intensities of
A temperature assumption step that assumes a plurality of temperatures of the predetermined part, and
The theoretical relationship between the intensity of each Raman scattered light on the Stokes side and the anti-Stokes side and the sample temperature, the detected light intensity on each side detected in the Raman scattered light intensity detection step, and the temperature assumption step. Correlation calculation step to obtain the correlation with the assumed relationship, which is the relationship with the assumed temperature assumed in, for each assumed temperature.
A temperature measuring method comprising a temperature specifying step for specifying a measurement temperature of a predetermined portion based on a correlation at each assumed temperature calculated in the correlation calculation step. For the theoretical formula showing the theoretical relationship between the Raman scattered light intensity and the sample temperature on the Stokes side and the anti-Stokes side, either the assumed temperature assumed in the temperature assumption step or the Raman scattered light intensity detection step detected. It has a theoretical light intensity calculation step that applies the detected light intensity, which is the Raman scattered light intensity on one side, and calculates the theoretical light intensity, which is the theoretical Raman scattered light intensity on the other side.
The temperature measuring method according to claim 1, wherein in the correlation calculation step, the correlation of the detected light intensity on the other side with respect to the theoretical light intensity on the other side is obtained for each of the plurality of assumed temperatures. The temperature measuring method according to claim 1 or 2, wherein the assumed temperature at which the correlation becomes the highest or becomes higher than a predetermined threshold value in the temperature specifying step is the measured temperature of the predetermined portion. In the Raman scattered light intensity detection step, the Stokes side detection light intensity and the anti-Stokes side detection light intensity at a plurality of different shift wavenumbers are detected, respectively.
In the theoretical light intensity calculation step, a plurality of theoretical light intensities on the other side corresponding to each detected light intensity on the other side detected in the Raman scattered light intensity detection step are calculated.
In the correlation calculation step, the correlation between each of the plurality of theoretical light intensities on the other side calculated in the theoretical light intensity calculation step and the plurality of detected light intensities on the other side detected in the Raman scattered light intensity detection step is obtained. The temperature measuring method according to claim 2, wherein the temperature is measured. In the Raman scattered light intensity detection step, each Raman scattered light intensity detected by the light detector via the spectroscope is interpolated to calculate continuous Stokes-side and anti-Stokes-side spectral data for the number of waves, and these spectra are calculated. The temperature measurement method according to claim 4, wherein the Stokes-side detected light intensity and the anti-Stokes-side detected light intensity are calculated from the data at a plurality of different shift wave numbers. A Raman spectroscopic analysis method using the temperature measuring method according to claim 1, 2, 3, 4 or 5.
An analysis step of analyzing the predetermined part of the sample based on the Raman scattered light,
A Raman spectroscopic analysis method comprising a display step for displaying the measured temperature at the same time on a display screen for displaying the analysis process or the analysis result in the analysis step. The Raman spectroscopic analysis method according to claim 6, wherein the temperature is measured a plurality of times during the analysis of a predetermined portion in the analysis step, and the measured temperature is updated and displayed each time the temperature is measured in the display step. The temperature of the predetermined part based on the light source that irradiates the predetermined part of the sample with the excitation light, the light detector that detects the Raman scattered light generated by the irradiation of the excitation light, and the Raman scattered light detected by the light detector. Equipped with a temperature measuring unit to measure
The temperature measuring unit
Based on the Raman scattered light detected by the light detector, the shift wave number at the wave number shifted from the wave number of the excitation light to the Stokes side and the anti-Stokes side by a predetermined shift wave number. A Raman scattered light intensity detector that detects a certain Stokes side light intensity and anti-Stokes side light intensity,
A temperature assumption part that assumes a plurality of temperatures of the predetermined part, and a temperature assumption part.
The theoretical relationship between the intensity of each Raman scattered light on the Stokes side and the anti-Stokes side and the sample temperature, the detected light intensity on each side detected by the Raman scattered light intensity detection unit, and the temperature assumption unit. A correlation calculation unit that obtains the correlation with the assumed relationship, which is the relationship with the assumed temperature assumed in, for each assumed temperature.
A temperature measuring device having a temperature specifying unit for specifying a measurement temperature of a predetermined portion based on a correlation at each assumed temperature calculated by the correlation calculating unit. The temperature measuring unit has the assumed temperature assumed by the temperature assumption unit and the Raman scattered light intensity with respect to the theoretical formula showing the theoretical relationship between the Raman scattered light intensity on the Stokes side and the anti-Stokes side and the sample temperature. It also has a theoretical light intensity calculation unit that applies the detected light intensity, which is the Raman scattered light intensity on either side, detected by the detection unit, and calculates the theoretical light intensity, which is the theoretical Raman scattered light intensity on the other side. ,
The temperature measuring device according to claim 8, wherein the correlation calculation unit obtains the correlation of the detected light intensity on the other side with respect to the theoretical light intensity on the other side for each of the plurality of assumed temperatures. A Raman spectroscopic analyzer having the temperature measuring device according to claim 8 or 9.
An analysis unit that analyzes the predetermined part of the sample based on the Raman scattered light, and
A Raman spectroscopic analyzer provided with a display unit that simultaneously displays the analysis process or analysis result in the analysis unit and the measurement temperature on the same screen. A program applied to a Raman spectroscopic analyzer or a temperature measuring device equipped with a light source that irradiates a predetermined portion of a sample with excitation light and a light detector that detects Raman scattered light generated by irradiation of the excitation light.
Based on the Raman scattered light detected by the light detector, the shift wave number at the wave number shifted from the wave number of the excitation light to the Stokes side and the anti-Stokes side by a predetermined shift wave number. A Raman scattered light intensity detector that detects a certain Stokes side light intensity and anti-Stokes side light intensity,
A temperature assumption part that assumes a plurality of temperatures of the predetermined part, and a temperature assumption part.
The theoretical relationship between the intensity of each Raman scattered light on the Stokes side and the anti-Stokes side and the sample temperature, the detected light intensity on each side detected by the Raman scattered light intensity detection unit, and the temperature assumption unit. A correlation calculation unit that obtains the correlation with the assumed relationship, which is the relationship with the assumed temperature assumed in, for each assumed temperature.
A program characterized by exerting a function as a temperature specifying unit that specifies the measured temperature of the predetermined portion based on the correlation at each assumed temperature calculated by the correlation calculation unit.

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