Analysis system

Abstract

An analysis system 1 comprises: an analysis device 10 which outputs light, receives input of scattered light resulting from scattering of the light on a surface of a measurement object, and detects a spectrum from the scattered light; a multicore optical fiber 20 which allows transmission of the light by using a first core and allows transmission of the scattered light by using a second core; and a probe head 30 which outputs the light transmitted by using the first core to the measurement object through an optics, and outputs the scattered light resulting from scattering of the light on the surface of the measurement object to the second core. The probe head changes the position of the light with respect to the measurement object by moving the position of the optics. The analysis device detects a plurality of spectra on a plurality of surfaces of the measurement object corresponding to a plurality of different positions of the light.

Description

Analysis System

[0001] The present disclosure relates to an analysis system.

[0002] There is a technique for measuring the Raman scattering spectrum of a measurement object (see Patent Document 1).

[0003] JP 2013-064711 A

[0004] However, they only measured the Raman scattering spectrum.

[0005] The present disclosure has been made in consideration of the above circumstances, and an object of the present disclosure is to provide a technique that contributes to the analysis of constituent substances of a measurement object.

[0006] An analysis system according to one aspect of the present disclosure includes an analysis device that outputs light, inputs scattered light scattered by the light on a surface of a measurement object, and detects a spectrum from the scattered light; a multi-core optical fiber that transmits the light through a first core and transmits the scattered light through a second core; and a probe head that outputs the light transmitted through the first core from an optical system to the measurement object, and outputs the scattered light scattered by the light on the surface of the measurement object to the second core, wherein the probe head changes the position of the light with respect to the measurement object by moving the position of the optical system, and the analysis device detects a plurality of spectra for a plurality of surfaces of the measurement object corresponding to a plurality of different positions of the light.

[0007] According to the present disclosure, a technique can be provided that contributes to the analysis of constituent substances of a measurement target.

[0008] Fig. 1 is a diagram showing the configuration of an analysis system according to this embodiment. Fig. 2 is a diagram showing an example of a multi-core optical fiber. Fig. 3 is a diagram showing the operation of the analysis system. Fig. 4 is a diagram showing the operation of the analysis system. Fig. 5 is a diagram showing the operation of the analysis system. Fig. 6 is a diagram showing the operation of the analysis system. Fig. 7 is a diagram showing the operation of the analysis system. Fig. 8 is a diagram showing the operation of the analysis system. Fig. 9 is a diagram showing the operation of the analysis system. Fig. 10 is a diagram showing examples of a plurality of Raman scattering spectra. Fig. 11 is a diagram showing examples of spectra of constituent substances.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same parts are designated by the same reference numerals and the description thereof will be omitted.

[0010] [Summary of the present disclosure] Conventional techniques only measure Raman scattering spectra. Furthermore, when a laser beam (probe beam) is irradiated onto the surface of a measurement object, a mixture of Raman scattering spectra generated from multiple constituent substances present near the surface is observed, making it difficult to separate and analyze the Raman scattering spectra of each individual constituent substance that makes up the measurement object.

[0011] Therefore, the present disclosure detects multiple Raman scattering spectra for multiple different surfaces of a measurement object by controlling the optical system in the probe head. For example, the Raman scattering spectrum of the entire surface of the measurement object is detected by two-dimensionally scanning the position of the focusing lens in the probe head with respect to the surface of the measurement object. This makes it possible to use these multiple Raman scattering spectra, thereby enabling analysis of the constituent substances of the measurement object.

[0012] Furthermore, the present disclosure uses an analytical device to simultaneously perform spectral decomposition on multiple Raman scattering spectra and compare the Raman scattering spectra of substances separated by the spectral decomposition with a Raman spectrum database, thereby enabling easy and accurate in situ analysis of the constituent substances of a measurement object without destroying the measurement object and extracting any part of it.

[0013] The above-described features of the present disclosure are also applicable to spectra such as reflection absorption spectra.

[0014] 1 is a diagram showing the configuration of an analysis system according to this embodiment. The analysis system 1 includes an analysis device 10, a multi-core optical fiber 20, and a probe head 30.

[0015] (Analyzing Device) The analyzing device 10 is a device that outputs laser light, inputs scattered light (Raman scattered light) scattered by the laser light on the surface of the measuring object 100, and detects a Raman scattering spectrum from the scattered light.

[0016] For example, the analysis device 10 includes a laser light source 11 , a spectrometer 12 , a detector 13 , a computer 14 , an estimation unit 15 , and a control unit 16 .

[0017] The laser light source 11 is a device that outputs laser light to the multi-core optical fiber 20. Note that since light has the property of traveling in a straight line, a simple light source that emits light may also be used.

[0018] The spectrometer 12 is an instrument that receives scattered light scattered on the surface of the object 100 to be measured by a laser beam from the multi-core optical fiber 20 and separates the scattered light.

[0019] The detector 13 is a device that detects a Raman scattering spectrum from the scattered light after dispersion. Specifically, the detector 13 detects each of the Raman scattering spectra from the scattered light scattered by each of the multiple different surfaces of the measurement object 100.

[0020] The calculator 14 is a computer that extracts, from the detected Raman scattering spectrum, the Raman scattering spectra of the constituent elements of the object 100. Specifically, the calculator 14 performs spectral resolution on the multiple Raman scattering spectra collectively, thereby separating the Raman scattering spectra of each constituent element that is mixed and distributed on the surface of the object 100 from the multiple Raman scattering spectra.

[0021] The estimation unit 15 is a computer that estimates the substances constituting the measurement object 100 from the Raman scattering spectrum of each extracted component. Specifically, the estimation unit 15 determines the constituent substances of the measurement object 100 by comparing the Raman scattering spectrum of each component separated from the multiple Raman scattering spectra with a spectrum database.

[0022] The control unit 16 is a device and / or a computer that controls the laser light source 11 , the spectrometer 12 , the detector 13 , the calculator 14 , and the estimation unit 15 .

[0023] (Multi-core optical fiber) The multi-core optical fiber 20 is an optical fiber that connects the analysis device 10 and the probe head 30. For example, a Y-branch optical fiber in which a central core 21 (first core) and a plurality of peripheral cores 22 (second cores) are branched midway in the longitudinal direction, as shown in Fig. 2, can be used.

[0024] The multi-core optical fiber 20 transmits the laser light from the analysis device 10 to the probe head 30 through a central core 21 (hereinafter referred to as a laser light core), and transmits the scattered light from the probe head 30 to the analysis device 10 through peripheral cores 22 (hereinafter referred to as a scattered light core). Note that a method of transmitting the laser light through the peripheral cores and the scattered light through the central core may also be considered.

[0025] (Probe Head) As shown in FIG. 1 , the probe head 30 is a device that outputs laser light transmitted through the multi-core optical fiber 20 (laser light cores 21) to the object to be measured 100, and outputs scattered light scattered on the surface of the object to be measured 100 by the laser light to the multi-core optical fiber 20 (scattered light cores 22).

[0026] The probe head 30 includes an optical system 31 including a first optical system 311 and a second optical system 312 , and a control unit 32 .

[0027] The first optical system (optical system) 311 is an optical system that includes a collimator lens and a condenser lens (not shown in Figure 1), and converts laser light into parallel rays using the collimator lens, condenses the parallel rays using the condenser lens, and outputs them to the object to be measured 100.

[0028] The second optical system 312 is an optical system that includes a collimator lens or a plurality of focusing lenses (not shown in FIG. 1 ), and converts the scattered light scattered by the laser light on the surface of the object to be measured 100 into parallel rays using the collimator lens, or focuses the scattered light using the plurality of focusing lenses, and outputs it to the multi-core optical fiber 20 (scattered light core 22).

[0029] The control unit 32 is a device, a circuit, a computer, or the like that controls the first optical system 311 and the second optical system 312. Specifically, the control unit 32 changes the position of the laser light relative to the measurement object 100 by moving the position of the first optical system 311.

[0030] 3, the laser light emitted from the laser light source 11 is converted into parallel rays by a collimator lens 41 and is incident on the laser light core 21. Alternatively, as shown in FIG. 4, the laser light may be focused by a condenser lens 42 and then incident on the laser light core 21.

[0031] Next, as shown in Figure 5, the laser light emitted from the opposite side of the laser light core 21 is converted into parallel rays by the collimator lens 311a in the first optical system 311, and the control unit 32 controls the position of the focusing lens 311b in the first optical system 311 to move back and forth in the z-axis direction so that the parallel rays are focused on the object to be measured 100.

[0032] Next, as shown in Fig. 6, the scattered light from the measurement object 100 is collimated by a collimator lens 312a in the second optical system 312, and the collimated light is input to the plurality of scattered light cores 22. Alternatively, as shown in Fig. 7, a plurality of condenser lenses 312b may be arranged in the second optical system 312 to condense the scattered light from the measurement object 100 and collect more scattered light.

[0033] Next, as shown in Figure 8, each scattered light emitted from the multiple scattered light cores 22 is converted into parallel rays by multiple collimator lenses 43, and each parallel beam is focused by a focusing lens 44 and directed to a spectrometer 12, where the Raman scattering spectrum is detected by a detector 13.

[0034] The method for detecting the Raman scattering spectrum on one surface of the measurement object 100 has been described above.

[0035] 9, the control unit 32 moves the position of the first optical system 311 on a plane perpendicular to the laser optical axis, that is, scans the xy plane, thereby focusing the laser light at different surface positions on the measurement object 100. Then, the detector 13 measures the Raman scattering spectrum of each.

[0036] At this time, the control unit 32 performs position control on the order of micrometers for the first optical system 311 by using an electrically controlled MEMS (Micro Electro Mechanical Systems) device such as a cantilever.

[0037] As a result, scattered light can be acquired while changing the measurement position on the surface of the measurement object 100 with micrometer-order precision, and the Raman scattering spectrum can be measured at each measurement position. In principle, since the diameter of the focused laser spot is on the order of the wavelength of the laser light, it is sufficient to be able to scan the measurement object 100 with micrometer-order resolution.

[0038] Thereafter, the computer 14 performs spectral decomposition on the multiple Raman scattering spectra collectively, thereby separating and extracting Raman scattering spectra corresponding to the individual molecular species that make up the object to be measured 100 from the mixed spectrum of the multiple molecular species that are mixed and distributed on the surface of the object to be measured 100.

[0039] As a method for separating and extracting spectra, for example, nonnegative factorization, which obtains compressed matrix decomposition under nonnegative constraints, can be applied. Multiple Raman scattering spectra are mixed spectra of multiple compounds present on the surface of the measurement object 100, but by performing matrix decomposition on the multiple Raman scattering spectra collectively, they can be decomposed into a matrix representing a spectrum unique to each chemical molecular species and a matrix representing the amounts of the components.

[0040] Fig. 10 shows multiple Raman scattering spectra measured on the surface of a metal oxide, while Fig. 11 shows the individual Raman scattering spectra of three molecular species distributed on the surface of the metal oxide, obtained by matrix decomposition of the multiple Raman scattering spectra.

[0041] Finally, the estimation unit 15 compares the separated and extracted individual Raman scattering spectra with a compound spectrum database of Raman scattering spectra, thereby estimating and calculating the constituent substances of the measurement object 100.

[0042] For example, the estimation unit 15 calculates the distance (e.g., Huffman distance or Kullback-Leibler distance) between each individual Raman scattering spectrum and each spectrum registered in the spectrum database, and presents the closest one or the Nth closest ones (N is a natural number) as the estimated compound. The three types of Raman scattering spectra shown in Figure 11 are estimated to be the β-iron oxyhydroxide Raman spectrum (thick line), the γ-iron oxyhydroxide Raman spectrum (dashed line), and fluorescence due to the fluorescent substance (thin line).

[0043] [Effect] According to this embodiment, the probe head 30 moves the position of the first optical system 311 to change the position of the laser light relative to the object to be measured 100, and the analyzing device 10 detects multiple Raman scattering spectra for multiple surfaces of the object to be measured 100 corresponding to the multiple different positions of the light, making it possible to use these multiple Raman scattering spectra and analyze the constituent substances of the object to be measured 100.

[0044] Furthermore, according to this embodiment, the analytical device 10 performs spectral decomposition on multiple Raman scattering spectra all at once, and compares the Raman scattering spectra of the components separated by this spectral decomposition with a Raman spectrum database. This makes it possible to easily and accurately analyze the constituent substances of the object to be measured 100 in situ, without destroying the object to be measured 100 and extracting any part of it.

[0045] [Modification] The present disclosure can be applied to other spectra by using the same system configuration and spectral decomposition method as described above. For example, by changing the laser light source 11 to a white light source with a wide wavelength range, the detector 13 can detect a reflection-absorption spectrum instead of a Raman scattering spectrum. The calculator 14 performs spectral decomposition of multiple reflection-absorption spectra instead of multiple Raman scattering spectra. The estimation unit 15 then compares the reflection-absorption spectrum with a compound spectrum database of reflection-absorption spectra instead of a compound spectrum database of Raman scattering spectra, thereby estimating and calculating the constituent substances of the measurement object 100. Using a similar mechanism, the present disclosure can be applied to spectra other than Raman scattering spectra and reflection-absorption spectra.

[0046] REFERENCE SIGNS LIST 1 Analysis system 10 Analysis device 11 Laser light source 12 Spectrometer 13 Detector 14 Calculator 15 Estimation unit 16 Control unit 20 Multi-core optical fiber 21 Central core, core for laser light, first core 22 Peripheral core, core for scattered light, second core 30 Probe head 31 Optical system 311 First optical system 311a Collimator lens 311b Collector lens 312 Second optical system 312a Collimator lens 312b Collector lens 32 Control unit 41 Collimator lens 42 Collector lens 43 Collimator lens 44 Collector lens 100 Measurement object

Claims

1. An analysis system comprising: an analyzer that outputs light, inputs scattered light caused by the light on the surface of a measurement object, and detects a spectrum from the scattered light; a multi-core optical fiber that transmits the light through a first core and transmits the scattered light through a second core; and a probe head that outputs the light transmitted through the first core from an optical system to the measurement object, and outputs the scattered light caused by the light on the surface of the measurement object to the second core, wherein the probe head changes the position of the light with respect to the measurement object by moving the position of the optical system; and the analyzer detects a plurality of spectra for a plurality of surfaces of the measurement object corresponding to a plurality of different positions of the light.

2. The analysis system according to claim 1, wherein the analysis device performs spectral decomposition on the plurality of spectra collectively to separate the spectra of each component constituting the object to be measured from the plurality of spectra, and compares the spectrum of each component with a spectral database to estimate the substance constituting the object to be measured.

3. The analysis system according to claim 2, wherein the spectral decomposition is a non-negative matrix factorization.

4. An analysis system according to any one of claims 1 to 3, wherein the spectrum is a Raman scattering spectrum or a reflection absorption spectrum.

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