Spectroscopic analysis device and spectroscopic analysis method

Abstract

In the spectroscopic analysis apparatus (1) according to the present disclosure, the control section (40) acquires the refractive index information of the sample (S) based on information of a first spectroscopic spectrum in a first wavelength band in which only a resonance spectrum of a surface plasmon is generated in a spectroscopic spectrum, and determines an incident angle of irradiation light (L1) irradiated by the irradiation section (10) with respect to the film (M) at which a peak wavelength of the resonance spectrum and a peak wavelength of an absorption spectrum of the sample (S) coincide with each other in a second spectroscopic spectrum in a second wavelength band in which the resonance spectrum and the absorption spectrum of the sample (S) are generated in the spectroscopic spectrum based on the acquired refractive index information, and analyzes the state of the sample (S) from information of the second spectroscopic spectrum obtained based on the determined incident angle.

Description

[0001] This application claims priority from Japanese Patent Application No. 2019-203646 filed November 11, 2019, the disclosure of which is incorporated herein in its entirety by reference. TECHNICAL FIELD

[0002] The present disclosure relates to a spectroscopic analysis apparatus and a spectroscopic analysis method. BACKGROUND

[0003] In the past, a technique of analyzing a state of a sample including a solution or the like based on a spectroscopic method has been known.

[0004] For example, in Non-Patent Literature 1, a surface plasmon resonance near-infrared spectroscopy (absorption response type near-infrared spectroscopy) in which free electrons in a metal are excited with light, and a resonance spectrum of surface plasmons and an absorption spectrum of a sample are overlapped so that the intensity of the absorption spectrum of the sample is apparently increased is disclosed.

[0005] Non-Patent Literature 1: Appl. Phys. Lett. 83, 2232 (2003); https: / / doi.org / 10.1063 / 1.1610812 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In such a conventional absorption response type near-infrared spectroscopy, if the refractive index of the sample changes in accordance with a change in the state of the sample including a composition of components or the like, the peak wavelength of the resonance spectrum of the surface plasmons changes, and the apparent intensity of the absorption spectrum of the sample decreases. At the time of the change in the state of the sample, in the change in the spectroscopic spectrum including the resonance spectrum and the absorption spectrum, it is difficult to distinguish the information of the change in the refractive index and the information related to the change in the state of the sample. According to the above, it is difficult to analyze the state of the sample with good accuracy.

[0008] An object of the present disclosure is to provide a spectroscopic analysis apparatus and a spectroscopic analysis method capable of analyzing a state of a sample with good accuracy.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] The spectroscopic analysis device according to some embodiments is a spectroscopic analysis device that analyzes a state of a sample disposed on a film that generates surface plasmons, and includes a control unit, an irradiation unit that irradiates the film with irradiation light, and a detection unit that detects measurement light including information of a spectroscopic spectrum, the measurement light being based on the irradiation light irradiated by the irradiation unit, the spectroscopic spectrum including a resonance spectrum of the surface plasmons and an absorption spectrum of the sample, the control unit acquiring information of a refractive index of the sample based on information of a first spectroscopic spectrum in a first wavelength band in which only the resonance spectrum is generated in the spectroscopic spectrum, the control unit determining an incident angle of the irradiation light irradiated by the irradiation unit with respect to the film at which a peak wavelength of the resonance spectrum and a peak wavelength of the absorption spectrum coincide with each other in a second spectroscopic spectrum in a second wavelength band in which the resonance spectrum and the absorption spectrum are generated in the spectroscopic spectrum based on the acquired information of the refractive index, and the control unit analyzing the state of the sample based on information of the second spectroscopic spectrum obtained based on the determined incident angle.

[0011] Thus, the spectroscopic analysis device can analyze the state of the sample with high precision. For example, the control unit acquires information of a refractive index of the sample based on information of a first spectroscopic spectrum in a first wavelength band in which only the resonance spectrum is generated. Thus, the control unit can correct the information of the refractive index by extracting only information of a refractive index change among an absorption change and a refractive index change accompanying a change in the state of the sample in the near-infrared region. Therefore, it is possible to compensate for stability of the spectroscopic spectrum with respect to the refractive index change in the near-infrared region and to acquire only information related to a change in the state of the sample with high precision. For example, the control unit determines the incident angle at which the peak wavelength of the resonance spectrum and the peak wavelength of the absorption spectrum coincide with each other and acquires information of the second spectroscopic spectrum based on the determined incident angle. Thus, the control unit can increase apparent intensity of the absorption spectrum of the sample and improve measurement sensitivity of the absorption spectrum caused by the sample.

[0012] In the spectroscopic analysis device according to one embodiment, the irradiation unit can include a first adjustment mechanism that is capable of adjusting the incident angle by control of the control unit, and the detection unit can include a second adjustment mechanism that is capable of adjusting a light-receiving angle by control of the control unit to detect the measurement light at an exit angle corresponding to the incident angle. Thus, the spectroscopic analysis device can optically adjust the optimal incident angle at which the peak wavelength of the resonance spectrum and the peak wavelength of the absorption spectrum coincide with each other. The spectroscopic analysis device can easily adjust the incident angle by feedback control of the control unit, for example.

[0013] In the spectroscopic analysis apparatus of one embodiment, the irradiation unit can also irradiate the sample with the irradiation light having the prescribed range of the incident angle together with the film, and the detection unit can include a photographing element having an arrangement of a plurality of pixels corresponding to one of the incident angles in the prescribed range and one of the wavelengths in the second wavelength band, respectively. Thus, compared to a case where the spectroscopic analysis apparatus has the first adjustment mechanism and the second adjustment mechanism, the spectroscopic analysis apparatus can be reduced in size. In addition, even when the refractive index of the sample changes, the incident angle of the irradiation light does not need to be adjusted to an optimal angle when the information of the second spectroscopic spectrum is obtained, and thus the sample can be easily measured.

[0014] In the spectroscopic analysis apparatus of one embodiment, the detection unit can include a wavelength separation element that separates first measurement light including information of the first spectroscopic spectrum and second measurement light including information of the second spectroscopic spectrum from the measurement light, and a first detector and a second detector that respectively detect the first measurement light and the second measurement light separated from each other by the wavelength separation element. Thus, the control unit can process the information of the first spectroscopic spectrum and the information of the second spectroscopic spectrum separately. Thus, the control unit can, for example, accurately correct the refractive index information on the basis of the information of the first spectroscopic spectrum. The control unit can, for example, accurately analyze the state of the sample on the basis of the information of the second spectroscopic spectrum obtained by adjusting the peak wavelength of the resonance spectrum using the corrected refractive index information.

[0015] In the spectroscopic analysis apparatus of one embodiment, the detection unit can include a wavelength dispersion element disposed between the wavelength separation element and the first detector, for spectroscopically analyzing the first measurement light separated by the wavelength separation element. Thus, the spectroscopic analysis apparatus can obtain the information of the first spectroscopic spectrum by spectroscopically analyzing the first measurement light.

[0016] In the spectroscopic analysis apparatus of one embodiment, the wavelength dispersion element can be an etalon filter. Thus, the spectroscopic analysis apparatus can obtain the information of the first spectroscopic spectrum as information of a change in intensity of the first measurement light. Thus, for example, compared to a case where the wavelength dispersion element includes a grating, the spectroscopic analysis apparatus can be reduced in size and in manufacturing cost.

[0017] In the spectroscopic analysis apparatus of one embodiment, the irradiation unit can include a single light source that irradiates the irradiation light having a wavelength band including the first wavelength band and the second wavelength band. Thus, the irradiation light of a wide wavelength band can be easily obtained by the single light source. Thus, for example, compared to a case where the irradiation unit includes a plurality of light sources, the spectroscopic analysis apparatus can be reduced in size and in manufacturing cost.

[0018] In the spectroscopic analysis apparatus of one embodiment, the above-described irradiation unit can include a first light source that irradiates first irradiation light having a wavelength band that is smaller than or equal to a full width at half maximum of the above-described resonance spectrum in the above-described first wavelength band, and a second light source that irradiates second irradiation light having the above-described second wavelength band. The above-described first detector detects the above-described first measurement light separated by the wavelength-separating element in a state where the intensity of the light of the above-described first measurement light changes based on the above-described resonance spectrum. Thus, the control unit can calculate the refractive index of the sample by measuring the intensity of the light of the first measurement light in the first detector.

[0019] In the spectroscopic analysis apparatus of one embodiment, the above-described first wavelength band can be included in a visible region and the above-described second wavelength band can be included in a near-infrared region. With the first wavelength band included in the visible region, the spectroscopic analysis apparatus can obtain refractive index information in a wavelength band in which the wavelength of light changes in response to the refractive index well. Thus, the accuracy of the refractive index information obtained by the spectroscopic analysis apparatus is improved. With the second wavelength band included in the near-infrared region, the spectroscopic analysis apparatus can analyze the state of a sample, for example, based on an absorption spectrum derived from molecular vibration.

[0020] The spectroscopic analysis method according to one embodiment is a spectroscopic analysis method performed by a spectroscopic analysis apparatus that analyzes a state of a sample provided on a film that generates surface plasmons, and includes: a step of irradiating the film with irradiation light; a step of detecting measurement light including information of a spectroscopic spectrum, the measurement light being based on the irradiation light, the spectroscopic spectrum including a resonance spectrum of the surface plasmons and an absorption spectrum of the sample; a step of obtaining refractive index information of the sample based on information of a first spectroscopic spectrum in a first wavelength band in which only the resonance spectrum is generated, in the spectroscopic spectrum; a step of determining an incident angle of the irradiation light with respect to the film, at which a peak wavelength of the resonance spectrum and a peak wavelength of the absorption spectrum coincide with each other, in a second spectroscopic spectrum in a second wavelength band in which the resonance spectrum and the absorption spectrum are generated, in the spectroscopic spectrum, based on the obtained refractive index information; and a step of analyzing the state of the sample from information of the second spectroscopic spectrum based on the determined incident angle.

[0021] Thus, the spectroscopic analysis apparatus can analyze the state of the sample with good precision. For example, the control section of the spectroscopic analysis apparatus acquires the refractive index information of the sample based on information of the first spectroscopic spectrum in the first wavelength band in which only the resonance spectrum is generated. Thus, the control section can extract only information of the refractive index change in the absorption change and the refractive index change accompanying the change in the state of the sample included in the near-infrared region to correct the refractive index information. Therefore, it is possible to compensate for the stability of the spectroscopic spectrum with respect to the refractive index change in the near-infrared region and to acquire only information related to the change in the state of the sample with good precision. For example, the control section determines the incident angle at which the peak wavelength of the resonance spectrum and the peak wavelength of the absorption spectrum coincide with each other, and acquires information of the second spectroscopic spectrum based on the determined incident angle. Thus, the control section can increase the apparent intensity of the absorption spectrum of the sample and improve the measurement sensitivity of the absorption spectrum caused by the sample.

[0022] According to the present disclosure, it is possible to provide a spectroscopic analysis apparatus and a spectroscopic analysis method that can analyze the state of a sample with good precision. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic view showing the schematic structure of a spectroscopic analysis apparatus according to an embodiment of the present disclosure.

[0024] Figure 2 is a block diagram corresponding to the schematic structure of the spectroscopic analysis apparatus of Figure 1

[0025] Figure 3

[0026] Figure 4 is a graph showing one example of a resonance spectrum in a visible region of surface plasmons in a metal thin film.

[0027] Figure 5 is a graph showing one example of the wavelength characteristics of an etalon filter included in the wavelength dispersion element.

[0028] Figure 6 is a graph showing one example of a resonance spectrum in a near-infrared region of surface plasmons in a metal thin film and an absorption spectrum of a sample.

[0029] Figure 7 is a flowchart for explaining one example of the operation of the spectroscopic analysis apparatus of Figure 1

[0030] Figure 8 is a schematic view for explaining a modification example of the spectroscopic analysis apparatus of Figure 1 DETAILED DESCRIPTION​​​​

[0031] Further details of the background and problems of the prior art are described.

[0032] In the past, it has been known that a sample is irradiated with irradiation light from an optical prism end abutting on the optical prism, and an attenuated total reflection (ATR) method is performed in which the emitted light from the optical prism which totally reflects at an angle of more than a critical angle is detected. In the ATR method, an evanescent wave based on the irradiation light is generated on the surface of the optical prism at the time of total reflection of the irradiation light. The ATR method is a method in which the evanescent wave is used to acquire an absorption spectrum of the sample.

[0033] However, the evanescent wave exists only on the surface of the optical prism. Therefore, there is a problem in that the irradiation light irradiated to the sample is weak, and the intensity of the absorption spectrum of the sample is low. In order to solve this problem, a surface plasmon resonance near-infrared spectroscopy (absorption response type near-infrared spectroscopy) has been developed in which free electrons in a metal are excited by light to resonate, thereby overlapping a resonance spectrum of surface plasmons and an absorption spectrum of a sample, and apparently increasing the intensity of the absorption spectrum of the sample.

[0034] In the past optical system for the absorption response type near-infrared spectroscopy, the irradiation light irradiated from a wideband light source propagates in a light guide member such as an optical fiber, is adjusted to be parallel light by a lens, a mirror, or the like, and is incident to a prism substrate in which a metal thin film is bonded. The metal thin film contains, for example, a thin film of gold, silver, copper, or the like. The prism substrate includes, for example, a cylindrical prism or a hemispherical prism. For example, a lens rotation mechanism for adjusting the incident angle of the irradiation light with respect to the metal thin film is provided in a lens for adjusting the irradiation light to be parallel light, and the interface between the metal thin film and the prism substrate is used as the center of the axis.

[0035] The emitted light which is reflected in the prism substrate passes through a polarizer having a rotation mechanism for controlling the polarized light of the emitted light, and is condensed by a lens, a mirror, or the like. For example, a lens rotation mechanism for adjusting the light receiving angle of the emitted light, with the interface between the metal thin film and the prism substrate as the center of the axis, is provided in a lens for condensing the emitted light. The emitted light which is adjusted to a prescribed light receiving angle propagates in a light guide member such as an optical fiber, and is detected by a spectrometer. A processing unit acquires information of a spectrogram based on the detected emitted light.

[0036] As described above, in the past absorption response type near-infrared spectroscopy, the irradiation light irradiated from a wideband light source is incident to a prism substrate in which a metal thin film is bonded. The emitted light which totally reflects at the interface of the prism substrate and is emitted is detected by a spectrometer as measurement light, after passing through a polarizer which is adjusted to exclude polarized light in a direction parallel to the interface of the prism substrate or polarized light in a direction perpendicular to the interface of the prism substrate.

[0037] In the case of polarized light perpendicular to the interface of the prism substrate (p-polarized light), an evanescent wave is generated. On the other hand, in the case of polarized light parallel to the interface of the prism substrate (s-polarized light), total internal reflection occurs at the interface of the metal thin film, and no evanescent wave is generated. Therefore, by rotating the polarizer and switching the polarization angle of the light to 0° (s-polarized light) or 90° (p-polarized light), the absorbed and unabsorbed measurement light are switched, enabling arbitrary detection. The processing unit calculates the difference between the information of the two measurement lights and subtracts the information of the surface plasmon resonance spectrum obtained through calculation, etc., to obtain the absorption spectrum of the sample.

[0038] Under total internal reflection conditions in an optical system where light is incident from the backside of a metal film, when the wavelength of the evanescent wave matches the wavelength of the surface plasmon, the evanescent wave and the surface plasmon resonate, resulting in maximum light absorption. The surface plasmon resonance spectrum depends on the refractive index of the sample on the metal film. More specifically, the maximum absorption wavelength, or peak wavelength, or angle of maximum absorption, of the surface plasmon resonance spectrum shifts depending on the sample's refractive index. Similarly, by varying the angle of incidence of the irradiating light relative to the metal film, the peak wavelength of the surface plasmon resonance spectrum shifts along the wavelength axis.

[0039] Therefore, the peak wavelength of the resonance spectrum can be shifted to a specific wavelength range, aligning the maximum light absorption wavelength under the resonance conditions with the peak wavelength of the sample's absorption spectrum. This apparently increases the intensity of the sample's absorption spectrum, enabling sensitive measurement of the sample's absorption spectrum.

[0040] Conventional absorption-responsive near-infrared spectroscopy, such as that described above, presents several problems when analyzing sample composition, for example, due to changes in the sample's refractive index caused by changes in composition. More specifically, conventional absorption-responsive near-infrared spectroscopy suffers from the problem that the peak wavelength of the surface plasmon resonance spectrum shifts due to changes in the refractive index associated with changes in the sample's composition, reducing the apparent intensity of the sample's absorption spectrum. Consequently, the spectral spectrum, including both the resonance spectrum and the absorption spectrum, becomes unstable with changes in the sample's composition.

[0041] When a sample's composition changes, it can be difficult to distinguish between information related to changes in the refractive index and information related to changes in the sample's composition. Consequently, for example, compensating for spectral stability based solely on information related to changes in the refractive index makes it difficult to accurately obtain only information related to changes in the sample's composition.

[0042] The present disclosure aims to provide a spectroscopic analysis device and a spectroscopic analysis method that can analyze the state of a sample with good precision. Hereinafter, an embodiment of the present disclosure will be described mainly with reference to the drawings.

[0043] Figure 1 is a schematic view showing the outline structure of a spectroscopic analysis device 1 according to an embodiment of the present disclosure. The spectroscopic analysis device 1 analyzes the state of a sample S disposed on a metal thin film M that generates surface plasmons. In the present specification, the "sample S" includes, for example, a solution. The "state of the sample S" includes, for example, the composition of components including the kind and ratio of components in the sample S, and an arbitrary physical or chemical parameter read from the absorption spectrum of another sample S. Referring to Figure 1 , the structure of the spectroscopic analysis device 1 according to an embodiment of the present disclosure will be described mainly.

[0044] The spectroscopic analysis device 1 has a single broadband light source 11 that irradiates irradiation light L1 having a wavelength band including a visible region and a near-infrared region, a light guide member 12 that guides the irradiation light L1 irradiated from the broadband light source 11, and a light parallelization member 13 that adjusts the irradiation light L1 emitted from the light guide member 12 to be parallel light. The irradiation light L1 emitted from the light parallelization member 13 is incident on a prism substrate P to which the metal thin film M is bonded. The metal thin film M includes, for example, a thin film of gold, silver, copper, or the like. The prism substrate P includes, for example, a cylindrical prism or a hemispherical prism. The sample S is disposed on the metal thin film M. The spectroscopic analysis device 1 has, for example, a first rotation mechanism 14 (first adjustment mechanism) that is installed to the light parallelization member 13 and adjusts the incident angle of the irradiation light L1 with respect to the metal thin film M with the interface between the metal thin film M and the prism substrate P as the center.

[0045] The spectroscopic analysis apparatus 1 has a polarizer 21 that has a second rotating mechanism 22 for controlling the polarized light of the measurement light L2 that is reflected in the prism substrate P, and a condensing member 23 that condenses the measurement light L2 that is emitted from the polarizer 21. The spectroscopic analysis apparatus 1 has, for example, a third rotating mechanism 24 (second adjusting mechanism) that is installed to the condensing member 23 and that adjusts the light-receiving angle of the measurement light L2 with the interface between the metal thin film M and the prism substrate P as the center. The spectroscopic analysis apparatus 1 has a wavelength separation element 25 for the visible region and the near-infrared region, a wavelength dispersion element 26 that spectrally disperses the first measurement light L21 of the visible region that is separated by the wavelength separation element 25, and a first detector 27 that detects the first measurement light L21 that is emitted from the wavelength dispersion element 26. The spectroscopic analysis apparatus 1 has a light guide member 28 that guides the second measurement light L22 of the near-infrared region that is separated by the wavelength separation element 25, and a second detector 29 that detects the second measurement light L22 that propagates in the light guide member 28.

[0046] The spectroscopic analysis apparatus 1 has a control section 40 that acquires information of a spectroscopic spectrum based on the detected measurement light L2. In the present specification, the "measurement light L2" includes, for example, the first measurement light L21 and the second measurement light L22. In the present specification, the "spectroscopic spectrum" includes, for example, the resonance spectrum of the surface plasmon in the metal thin film M and the absorption spectrum of the sample S. In the present specification, the "information of the spectroscopic spectrum" includes, for example, the profile information of the entire spectroscopic spectrum that is acquired in a prescribed wavelength range as described later. However, the "information of the spectroscopic spectrum" can include, for example, the information of the light intensity of the measurement light L2 that is obtained by transforming the profile information of the spectroscopic spectrum along the wavelength axis by an optical filter that transmits only a fixed portion of the wavelength region. Figure 4 and Figure 6 The spectroscopic analysis apparatus 1 has a control section 40 that acquires information of a spectroscopic spectrum based on the detected measurement light L2. In the present specification, the "measurement light L2" includes, for example, the first measurement light L21 and the second measurement light L22. In the present specification, the "spectroscopic spectrum" includes, for example, the resonance spectrum of the surface plasmon in the metal thin film M and the absorption spectrum of the sample S. In the present specification, the "information of the spectroscopic spectrum" includes, for example, the profile information of the entire spectroscopic spectrum that is acquired in a prescribed wavelength range as described later. However, the "information of the spectroscopic spectrum" can include, for example, the information of the light intensity of the measurement light L2 that is obtained by transforming the profile information of the spectroscopic spectrum along the wavelength axis by an optical filter that transmits only a fixed portion of the wavelength region.

[0047] Figure 2 is a block diagram corresponding to the schematic structure of the spectroscopic analysis apparatus 1 of Figure 1 . Referring to Figure 1 and Figure 2 , the structure of the spectroscopic analysis apparatus 1 according to an embodiment of the present disclosure is described in more detail.

[0048] The spectroscopic analysis apparatus 1 has, in addition to the control section 40 described above, an irradiation section 10, a detection section 20, and a storage section 30.

[0049] The irradiation section 10 includes an arbitrary optical system that irradiates the metal thin film M with the irradiation light L1. For example, the irradiation section 10 includes the broadband light source 11, the light guide member 12, the light parallelization member 13, and the first rotating mechanism 14 described above.

[0050] The wideband light source 11 includes, for example, a single light source that irradiates the irradiation light Ll having a wavelength band including a visible region and a near infrared region. The light guide member 12 can include, for example, an optical fiber, and can include a spatial optical member such as a lens, a mirror, and the like. The light parallelization member 13 includes, for example, a spatial optical member such as a lens, a mirror, and the like. The first rotation mechanism 14 includes an arbitrary mechanism that can rotate the light parallelization member 13 with the interface between the metal thin film M and the prism substrate P as a center, to adjust the incident angle of the irradiation light Ll with respect to the metal thin film M.

[0051] The detection section 20 includes an arbitrary optical system that detects the measurement light L2 including information of a spectroscopic light spectrum, which is based on the irradiation light Ll irradiated by the irradiation section 10. For example, the detection section 20 includes the above-described polarizer 21, the second rotation mechanism 22, the light condensing member 23, the third rotation mechanism 24, the wavelength separation element 25, the wavelength dispersion element 26, the first detector 27, the light guide member 28, and the second detector 29.

[0052] The second rotation mechanism 22 includes an arbitrary mechanism that can rotate the polarizer 21, to control the polarized light of the measurement light L2 that is reflected in the prism substrate P. The light condensing member 23 includes, for example, a spatial optical member such as a lens, a mirror, and the like. The third rotation mechanism 24 includes an arbitrary mechanism that can rotate the light condensing member 23 with the interface between the metal thin film M and the prism substrate P as a center, to adjust the light receiving angle of the measurement light L2. The wavelength separation element 25 includes, for example, a dichroic mirror. The wavelength dispersion element 26 includes, for example, an etalon filter. The first detector 27 includes, for example, a detector having a visible region detection element. The light guide member 28 can include, for example, an optical fiber, and can include a spatial optical member such as a lens, a mirror, and the like. The second detector 29 includes, for example, a spectroscopic light detector having a near infrared region detection element and a near infrared region spectroscopic light element.

[0053] The storage section 30 includes any storage module including an HDD (Hard Disk Drive), an SSD (Solid State Drive), an EEPROM (Electrically Erasable Programmable Read-Only Memory), a ROM (Read-Only Memory), and a RAM (Random Access Memory). The storage section 30 can function as a main storage device, an auxiliary storage device, or a cache memory, for example. The storage section 30 stores any information used in the operation of the spectrometer 1. For example, the storage section 30 can store information of a spectrogram detected by the detection section 20. The storage section 30 can also store a system program, an application program, and the like, for example. The storage section 30 is not limited to being built into the spectrometer 1, but can be an external storage module connected through a digital input / output port such as a USB (Universal Serial Bus).

[0054] The control section 40 includes one or more processors. In one embodiment, the "processor" is a general-purpose processor or a dedicated processor dedicated to a specific process, but is not limited thereto. The control section 40 is communicably connected to each of the constituent sections constituting the spectrometer 1 and controls the operation of the entire spectrometer 1.

[0055] Referring again to Figure 1 , the function of the optical system in the spectrometer 1 will be mainly described.

[0056] In the spectrometer 1, the irradiation light L1 irradiated from the broadband light source 11 is incident on the prism substrate P having the metal thin film M bonded thereto via the light guide member 12 and the light parallelization member 13. The measurement light L2 totally reflected at the interface of the prism substrate P and emitted passes through the polarizer 21 adjusted to exclude polarized light in a direction parallel to the interface of the prism substrate P or polarized light in a direction perpendicular to the interface of the prism substrate P, and is condensed by the condensing member 23. The measurement light L2 condensed by the condensing member 23 is detected by the first detector 27 and the second detector 29.

[0057] In the case of polarized light (p-polarized light) in the direction perpendicular to the interface of the prism substrate P, an evanescent wave is generated. On the other hand, in the case of polarized light (s-polarized light) in the direction parallel to the interface of the prism substrate P, total reflection occurs at the interface of the metal thin film M without generating an evanescent wave. Therefore, by rotating the polarizer 21 to switch the azimuth angle of the polarized light to 0° (s-polarized light) or 90° (p-polarized light), the measurement light L2 that is absorbed and the measurement light L2 that is not absorbed are switched, and thus arbitrary detection can be performed. The control section 40 calculates the difference between the information of the two measurement lights L2, and subtracts the information of the resonance spectrum of the surface plasmon obtained by calculation or the like, and thus the absorption spectrum can be obtained.

[0058] In the total reflection condition of the optical system in which the irradiation light L1 is incident from the back surface of the metal thin film M, when the wavelength of the evanescent wave coincides with the wavelength of the surface plasmon, the evanescent wave resonates with the surface plasmon, and great light absorption occurs. The resonance spectrum of the surface plasmon depends on the refractive index of the sample S on the metal thin film M. More specifically, based on the refractive index of the sample S, the maximum absorption wavelength, i.e., the peak wavelength, or the maximum absorption angle of the resonance spectrum of the surface plasmon shifts. Similarly, by changing the incident angle of the irradiation light L1 with respect to the metal thin film M, the peak wavelength of the resonance spectrum of the surface plasmon changes in the wavelength axis direction.

[0059] Therefore, it is possible to shift the peak wavelength of the resonance spectrum to a specific wavelength range to coincide the maximum light absorption wavelength in the resonance condition with the peak wavelength of the absorption spectrum of the sample S. As a result, the intensity of the absorption spectrum of the sample S is apparently increased, and the measurement sensitivity of the absorption spectrum caused by the sample S is improved.

[0060] In the spectrometric analysis device 1, the measurement light L2 condensed by the condensing member 23 is separated by the wavelength separation element 25 into the first measurement light L21 including the information of the first spectrometric spectrum, and the second measurement light L22 including the information of the second spectrometric spectrum.

[0061] In the present specification, the "first spectrometric spectrum" includes, for example, the spectrum in the first wavelength band of the spectrometric spectrum in which only the resonance spectrum of the surface plasmon in the metal thin film M is generated. In the present specification, the "first wavelength band" includes, for example, in the visible region. In the present specification, the "visible region" includes, for example, the wavelength region of light of 400 nm or more and less than 800 nm. For example, the sample S does not include the complex refractive index in the visible region, i.e., information related to absorption, and does not exhibit an arbitrary absorption spectrum.

[0062] In the present specification, the "second spectroscopic light" includes, for example, a spectrum in a second wavelength band in which a resonance spectrum of the surface plasmon in the metal thin film M and an absorption spectrum of the sample S are generated. In the present specification, the "second wavelength band" is included, for example, in the near-infrared region. In the present specification, the "near-infrared region" includes, for example, a wavelength region of light of 800 nm or more and less than 2.5 μm.

[0063] The first measurement light L21 of the visible region separated by the wavelength separation element 25 is incident on the wavelength dispersion element 26, and is detected by the visible region detection element in the first detector 27. The control section 40 acquires information of the first spectroscopic light based on the detection information output from the first detector 27.

[0064] Figure 3 is a graph showing one example of the wavelength dispersion of the refractive index of a substance. In Figure 3 , the vertical axis is the refractive index, the horizontal axis is the wavelength, and the wavelength dispersion of the refractive index is shown for three substances of water, ethylene glycol, and ethanol.

[0065] As shown in Figure 3 , generally, in the wavelength dispersion of the refractive index of a substance, the change in the refractive index of the visible region is larger than the change in the refractive index of the near-infrared region. Therefore, in the visible region, the wavelength of light has a good responsiveness to the change in the refractive index.

[0066] Figure 4 is a graph showing one example of the resonance spectrum of the surface plasmon in the visible region in the metal thin film M. In Figure 4 , it is shown that, each time the refractive index of the sample S changes to n1, n2, and n3, the peak wavelength of the resonance spectrum of the surface plasmon in the visible region in the metal thin film M shifts to λ1, λ2, and λ3 on the wavelength axis. The information of the first spectroscopic light is stored in the storage section 30, for example, as information of the resonance spectrum of the surface plasmon reflecting the change in the refractive index of the sample S.

[0067] For example, when the refractive index of the sample S changes according to a change in the composition of the sample S, a change in the temperature, or a change in the pressure, or the like, as shown in Figure 4 , the peak wavelength of the resonance spectrum of the surface plasmon in the visible region in the metal thin film M changes. The control section 40 acquires the refractive index information of the sample S based on such information of the first spectroscopic light. In the present specification, the "refractive index information" includes, for example, the value of the refractive index and the differential value of the value of the refractive index accompanying the change in the refractive index.

[0068] Figure 5 is a graph showing one example of the wavelength characteristics of the etalon filter included in the wavelength dispersion element 26. As Figure 5As shown, the etalon filter included in the wavelength dispersion element 26 has, for example, a wavelength characteristic in which the peak wavelength of the transmittance is located on the low wavelength side than λ1, and the flatness of the profile on the high wavelength side relative to the peak wavelength extends from λ1 to λ3.

[0069] For example, when the refractive index of the sample S changes to n1, n2, and n3, and the peak wavelength of the resonance spectrum in the visible region of the surface plasmon in the metal thin film M changes to λ1, λ2, and λ3, respectively, the intensity of the first measurement light L21 changes based on the absorption of the surface plasmon and the transmittance of the etalon filter. The control section 40 acquires the refractive index information of the sample S based on the information of the first spectroscopic spectrum that is the information of the intensity change of the first measurement light L21. More specifically, the control section 40 calculates the light intensity of the first measurement light L21 from the detection information output from the first detector 27, and calculates the changed refractive index of the sample S based on the calculated light intensity of the first measurement light L21.

[0070] The second measurement light L22 in the near-infrared region separated by the wavelength separation element 25 is detected by, for example, a spectroscope having a near-infrared region spectroscopic element and a near-infrared region detection element in the second detector 29. The control section 40 acquires the information of the second spectroscopic spectrum based on the detection information output from the second detector 29.

[0071] Figure 6 is a graph showing one example of the resonance spectrum in the near-infrared region of the surface plasmon in the metal thin film M and the absorption spectrum of the sample S. In Figure 6 In, for example, the peak wavelength of the resonance spectrum in the near-infrared region and the peak wavelength of the absorption spectrum are different from each other as the refractive index of the sample S changes. In this way, the information of the second spectroscopic spectrum is stored in, for example, the storage section 30 as information that reflects the information of the resonance spectrum of the surface plasmon and the complex refractive index of the substance, that is, the information related to the absorption, of the sample S as the refractive index changes.

[0072] In the second spectroscopic spectrum, the control section 40 determines the incident angle of the irradiation light L1 irradiated by the irradiation section 10 relative to the metal thin film M at which the peak wavelength of the resonance spectrum and the peak wavelength of the absorption spectrum coincide with each other based on the refractive index information of the sample S acquired through the information of the first spectroscopic spectrum. For example, the control section 40 calculates the incident angle as the resonance condition in the near-infrared region at which the peak wavelength of the resonance spectrum and the peak wavelength of the absorption spectrum coincide with each other based on the refractive index of the sample S calculated from the resonance spectrum in the visible region of the surface plasmon. At this time, the peak wavelength of the absorption spectrum of the sample S as the target of the coincidence of the peak wavelength of the resonance spectrum is known. Therefore, the control section 40 calculates the incident angle as the resonance condition in the near-infrared region based on the refractive index of the sample S and the peak wavelength of the absorption spectrum.

[0073] The control unit 40 analyzes the state of the sample S based on the information from the second spectroscopic spectrum obtained based on the determined incident angle. At this point, the control unit 40 performs feedback control, or in other words, angle control, on the first and third rotating mechanisms 14 and 24 based on the incident angle, which serves as the determined resonance condition, to achieve the desired resonance condition in the near-infrared region. More specifically, the control unit 40 controls the first rotating mechanism 14 of the irradiation unit 10 to achieve the desired incident angle. The control unit 40 controls the third rotating mechanism 24 of the detection unit 20 to adjust the light receiving angle in order to detect the second measurement light L22 at an emission angle corresponding to the determined incident angle.

[0074] For example, Figure 6 As shown, the control unit 40 adjusts the peak wavelength of the near-infrared resonance spectrum of the surface plasmons by varying the incident angle of irradiation light L1. For example, each time the incident angle of irradiation light L1 changes to θ1, θ2, and θ3, the peak wavelength of the near-infrared resonance spectrum of the surface plasmons in the metal thin film M shifts on the wavelength axis to λ4, λ5, and λ6, respectively. By aligning the peak wavelength of the resonance spectrum with the peak wavelength of the absorption spectrum, the control unit 40 can effectively increase the intensity of the absorption spectrum of the sample S.

[0075] Figure 7 It is used for Figure 1 A flowchart illustrating an example of the operation of the spectroscopic analysis device 1 is provided. Figure 7 , an example of the operation of the spectroscopic analysis device 1 will be mainly described.

[0076] In step S100 , the control unit 40 irradiates the metal thin film M with the irradiation light L1 using the irradiation unit 10 .

[0077] In step S101 , the control unit 40 detects measurement light L2 including spectral spectrum information including the resonance spectrum of the surface plasmon and the absorption spectrum of the sample S based on the irradiation light L1 irradiated by the irradiation unit 10 in step S100 through the detection unit 20 .

[0078] In step S102 , the control unit 40 acquires the refractive index information of the sample S based on information of the first spectral spectrum in the first wavelength band where the resonance spectrum occurs, among the spectral spectrums included as information in the measurement light L2 detected in step S101 .

[0079] In step S103, the control section 40 determines the incident angle of the irradiation light Ll at which the peak wavelength of the resonance spectrum and the peak wavelength of the absorption spectrum coincide with each other, in the second spectral light spectrum in the second wavelength band in which the resonance spectrum and the absorption spectrum are generated, among the spectral light spectrum detected in step S101 as information having the refractive index information acquired in step S102.

[0080] In step S104, the control section 40 analyzes the state of the sample S from the information of the second spectral light spectrum based on the incident angle determined in step S103.

[0081] According to the spectral analysis device 1 related to the embodiment described above, the state of the sample S can be analyzed with good precision. For example, the control section 40 acquires the refractive index information of the sample S based on the information of the first spectral light spectrum in the first wavelength band in which only the resonance spectrum is generated. Thus, the control section 40 can correct the refractive index information by extracting only the information of the refractive index change among the absorption change and the refractive index change accompanying the change in the state of the sample S included in the near-infrared region. Therefore, the stability of the spectral light spectrum with respect to the refractive index change in the near-infrared region can be compensated for, and only the information related to the change in the state of the sample S can be acquired with good precision. For example, the control section 40 determines the incident angle at which the peak wavelength of the resonance spectrum and the peak wavelength of the absorption spectrum coincide with each other, and acquires the information of the second spectral light spectrum based on the determined incident angle. Thus, the control section 40 can increase the apparent intensity of the absorption spectrum of the sample S, and improve the measurement sensitivity of the absorption spectrum caused by the sample S.

[0082] For example, the spectral analysis device 1 can optically adjust the optimum incident angle at which the peak wavelength of the resonance spectrum and the peak wavelength of the absorption spectrum coincide with each other, by having the first rotating mechanism 14 and the third rotating mechanism 24. The spectral analysis device 1 can easily adjust the incident angle, for example, by feedback control of the control section 40.

[0083] For example, by including the first rotating mechanism 14 and the third rotating mechanism 24, and being able to simultaneously measure the first spectral light spectrum of the visible region and the second spectral light spectrum of the near-infrared region, Figure 1 The same optical system shown in the drawing maintains the simultaneity of the correction of the refractive index information, that is, the correction of the incident angle of the irradiation light Ll, and the information of the change in the state of the sample S. Therefore, in the second spectral light spectrum of the near-infrared region, the peak wavelength of the resonance spectrum can be adjusted with good precision based on the correction accuracy of the refractive index information that correctly corresponds in time.

[0084] For example, by including the first rotating mechanism 14 and the third rotating mechanism 24, Figure 1The coaxial optical system shown suppresses a spatial deviation of the measurement position in the sample S, and can maintain the identity of the measurement position in the sample S. Thus, the spectroscopic analysis device 1 can correct the refractive index information while ensuring the identity of the measurement position in the sample S, with respect to the acquired first and second spectroscopic spectra.

[0085] By including the wavelength separation element 25, the first detector 27, and the second detector 29 in the detection section 20, the control section 40 can distinguish the information of the first spectroscopic spectrum and the information of the second spectroscopic spectrum and process them individually. Thus, the control section 40 can, for example, accurately correct the refractive index information based on the information of the first spectroscopic spectrum. The control section 40 can, for example, accurately analyze the state of the sample S based on the information of the second spectroscopic spectrum obtained by adjusting the peak wavelength of the resonance spectrum based on the corrected refractive index information.

[0086] By including the wavelength dispersion element 26 in the detection section 20, the spectroscopic analysis device 1 can acquire the information of the first spectroscopic spectrum by spectroscopically analyzing the first measurement light L21. For example, by including an etalon filter in the wavelength dispersion element 26, the spectroscopic analysis device 1 can acquire the information of the first spectroscopic spectrum as information of the intensity variation of the first measurement light L21. Thus, for example, compared to a case where the wavelength dispersion element 26 includes a grating, the spectroscopic analysis device 1 can be downsized and the manufacturing cost of the spectroscopic analysis device 1 can be reduced.

[0087] By including a single light source that emits the measurement light L1 having a wavelength band including the first and second wavelength bands in the irradiation section 10, a wideband of the measurement light L1 can be easily obtained by a single light source. Thus, for example, compared to a case where the irradiation section 10 includes a plurality of light sources, the spectroscopic analysis device 1 can be downsized and the manufacturing cost of the spectroscopic analysis device 1 can be reduced.

[0088] By including the first wavelength band in the visible region, the spectroscopic analysis device 1 can acquire the refractive index information in a wavelength band in which the responsiveness of light to the refractive index variation is good. Thus, the accuracy of the refractive index information acquired by the spectroscopic analysis device 1 is improved. By including the second wavelength band in the near-infrared region, the spectroscopic analysis device 1 can analyze the state of the sample S based on, for example, an absorption spectrum derived from molecular vibrations.

[0089] The present disclosure is described based on the drawings and the embodiments, but it is noted that various modifications and changes can be easily made by those skilled in the art based on the present disclosure. Therefore, it is noted that these modifications and changes are also included in the scope of the present disclosure. For example, the shape, arrangement, direction, and number of each structure are not limited to those illustrated in the foregoing description and the drawings. As long as the shape, arrangement, direction, and number of each structure can achieve the function thereof, they can be arbitrarily configured. For example, the functions and the like included in each structure or each step can be reconfigured as long as they are not logically contradictory, and a plurality of structures or steps can be combined into one or divided.

[0090] For example, the present disclosure can also be implemented as a program or a storage medium in which the program is recorded, which describes the processing content of each function of the above-described spectrometer 1. It is understood that these are also included in the scope of the present disclosure.

[0091] Figure 8 is a schematic view for explaining a modification example of the spectrometer 1 of Figure 1 . Referring to Figure 8 , a modification example of the spectrometer 1 of Figure 1 will mainly be explained. In Figure 8 , the appearance of the second spectrogram that changes depending on the incident angles θ1, θ2, θ3, θ4, θ5, θ6, and θ7 of the irradiation light L1 and the appearance of the allocation of the incident angle and the wavelength with respect to each pixel of the imaging element included in the second detector 29 are illustrated.

[0092] In the above, it is explained that the spectrometer 1 has the first rotating mechanism 14 and the third rotating mechanism 24, adjusts the incident angle of the irradiation light L1 and the light-receiving angle of the measurement light L2, and performs the measurement by the detection section 20 based on one set of the incident angle and the light-receiving angle, but it is not limited thereto. The spectrometer 1 can also not have the first rotating mechanism 14 and the third rotating mechanism 24.

[0093] At this time, the irradiation section 10 can also irradiate the metal thin film M with the irradiation light L1 having the prescribed range of the incident angle. The detection section 20, more specifically, the second detector 29 can include an imaging element having an arrangement of a plurality of pixels corresponding to one incident angle in the prescribed range and one wavelength in the second wavelength band, respectively.

[0094] For example, the irradiation section 10 can also irradiate the metal thin film M with the irradiation light L1 having the incident angles of θ1, θ2, θ3, θ4, θ5, θ6, and θ7. For example, the second detector 29 can also include a shooting element whose longitudinal axis corresponds to θ1, θ2, θ3, θ4, θ5, θ6, and θ7, and whose lateral axis corresponds to the wavelength in the second waveband. For example, the control section 40 can also select a row of pixels corresponding to the incident angle of the irradiation light L1 that matches the resonance condition, based on the information of the first spectrogram, and acquire an appropriate second spectrogram. As above, the spectroscopic analysis device 1 can also acquire the information of the second spectrogram together with the angle information including the incident angle.

[0095] By the detection section 20 of the spectroscopic analysis device 1 including the shooting element as described above, the spectroscopic analysis device 1 does not have the first rotation mechanism 14 and the third rotation mechanism 24, and thus can achieve miniaturization of the spectroscopic analysis device 1. In addition to this, even when the refractive index of the sample S changes, there is no need to adjust the incident angle of the irradiation light L1 to the optimum angle when acquiring the information of the second spectrogram, and measurement is easy.

[0096] In the above, it is described that the irradiation section 10 includes a single light source that irradiates the irradiation light L1 having a waveband including a visible region and a near-infrared region, and that the detection section 20 includes the wavelength dispersion element 26 for spectroscopically analyzing the first measurement light L21 separated by the wavelength separation element 25, but is not limited thereto. For example, the irradiation section 10 can include a first light source that irradiates first irradiation light L11 having a waveband of half-peak full width or less of a resonance spectrum of surface plasmons in a first waveband, and a second light source that irradiates second irradiation light L12 having a second waveband. The first light source can include, for example, an LED (Light Emitting Diode) or an LD (Laser Diode). At this time, the detection section 20 can not include the wavelength dispersion element 26.

[0097] The first detector 27 can also detect the first measurement light L21 separated by the wavelength separation element 25 in a state where the light intensity of the first measurement light L21 changes based on the resonance spectrum of surface plasmons. For example, when the peak wavelength of the resonance spectrum of surface plasmons in the first waveband matches the center wavelength of the first irradiation light L11 irradiated from the first light source, the absorption amount of the first irradiation light L11 by the metal thin film M is the largest, and the light intensity of the first measurement light L21 in the first detector 27 is the lowest. When the peak wavelength of the resonance spectrum of surface plasmons shifts in conjunction with a change in the refractive index of the sample S, the light intensity of the first measurement light L21 in the first detector 27 increases. Therefore, the control section 40 can also calculate the refractive index of the sample S by measuring the light intensity of the first measurement light L21 in the first detector 27.

[0098] In the above description, it has been described that the irradiation section 10 includes, for example, a single light source that irradiates the irradiation light Ll having a wavelength band including the visible region and the near-infrared region, but is not limited thereto. For example, the irradiation section 10 can include a first light source that irradiates the first irradiation light Ll l having a first wavelength band, and a second light source that irradiates the second irradiation light L12 having a second wavelength band. For example, the irradiation section 10 can include a single light source that can scan the center wavelength of the irradiation light Ll in a narrow band from the visible region to the near-infrared region. For example, the irradiation section 10 can include a first light source that can scan the center wavelength of the first irradiation light Ll l in a narrow band in the visible region, and a second light source that can scan the center wavelength of the second irradiation light L12 in a narrow band in the near-infrared region.

[0099] In the above description, it has been described that, in the detection section 20, the wavelength dispersion element 26 and the first detector 27 are separate, but is not limited thereto. The detection section 20 can have the first detector 27 as a single spectrometer in which these constituent sections are integrated, like the second detector 29. In the above description, it has been described that the detection section 20 includes the second detector 29 as a spectrometer that includes the near-infrared region spectrometric element and the near-infrared region detection element, but is not limited thereto. In the detection section 20, the near-infrared region spectrometric element and the near-infrared region detection element can be separate.

[0100] In the above description, it has been described that the detection section 20 includes the wavelength separation element 25, the first detector 27, and the second detector 29, but is not limited thereto. For example, the detection section 20 can not have the wavelength separation element 25, the first detector 27, and the second detector 29, but can have a single spectrometer that can spectrometrically separate from the visible region to the near-infrared region.

[0101] In the above description, it has been described that the wavelength dispersion element 26 is a etalon filter, but is not limited thereto. The wavelength dispersion element 26 can include, for example, a grating, or can include a wavelength variable band pass filter that can scan the center wavelength in the first wavelength band. At this time, the control section 40 can acquire information of the first spectrometric spectrum as profile information. The control section 40 can calculate the refractive index of the sample S corresponding to the peak wavelength of the resonance spectrum in the visible region acquired after the refractive index of the sample S is changed.

[0102] In the above description, it has been described that the first wavelength band is included in the visible region, and the second wavelength band is included in the near-infrared region, but is not limited thereto. The first wavelength band can be included in an arbitrary wavelength band in which only the resonance spectrum of the surface plasmon of the metal thin film M is generated in the spectrometric spectrum. The second wavelength band can be included in an arbitrary wavelength band in which the resonance spectrum of the surface plasmon in the metal thin film M and the absorption spectrum of the sample S are generated in the spectrometric spectrum.

[0103] In the above, the metal thin film M has been described as being joined to the prism substrate P, but is not limited thereto. For example, any film that generates surface plasmons can be joined to the prism substrate P.

[0104] Reference Signs

[0105] 1 spectrometer; 10 irradiation section; 11 wideband light source; 12 light guide member; 13 light parallelizing member; 14 first rotation mechanism (first adjustment mechanism); 20 detection section; 21 polarizer; 22 second rotation mechanism; 23 light collecting member; 24 third rotation mechanism (second adjustment mechanism); 25 wavelength separation element; 26 wavelength dispersion element; 27 first detector; 28 light guide member; 29 second detector; 30 storage section; 40 control section; LI irradiation light; LI 1 first irradiation light; LI 2 second irradiation light; L2 measurement light; L21 first measurement light; L22 second measurement light; M metal thin film; P prism substrate; S sample; Q1, Q2, Q3, Q4, Q5, Q6, Q7 incident angle.

Claims

1. A spectroscopic analysis apparatus for analyzing the state of a sample disposed on a film generating surface plasmons, comprising: Control Department; an irradiation unit for irradiating the film with irradiation light; and a detection unit that detects measurement light including information of a spectral spectrum based on the irradiation light irradiated by the irradiation unit, the spectral spectrum including a resonance spectrum of the surface plasmon and an absorption spectrum of the sample; The control unit acquires the refractive index information of the sample based on information of a first spectral spectrum in a first wavelength band that generates only the resonance spectrum in the spectral spectrum. The control unit determines, based on the acquired refractive index information, an incident angle of the irradiation light irradiated by the irradiation unit with respect to the film at which the peak wavelength of the resonance spectrum and the peak wavelength of the absorption spectrum coincide with each other in a second spectral spectrum in the second wavelength band of the spectral spectrum that generates the resonance spectrum and the absorption spectrum. The control unit analyzes the state of the sample based on information of the second spectroscopic spectrum obtained based on the determined incident angle.

2. The spectroscopic analysis device according to claim 1, wherein The irradiation unit includes a first adjustment mechanism, and the first adjustment mechanism can adjust the incident angle under the control of the control unit. The detection unit includes a second adjustment mechanism capable of adjusting a light receiving angle under the control of the control unit so as to detect the measurement light at an emission angle corresponding to the incident angle.

3. The spectroscopic analysis device according to claim 1, wherein The irradiation unit irradiates the film with the irradiation light having the incident angle within the predetermined range. The detection unit includes an imaging element having an array of a plurality of pixels corresponding to each of the incident angles within the predetermined range and a wavelength in the second wavelength band.

4. The spectroscopic analysis device according to any one of claims 1 to 3, wherein The detection unit includes: a wavelength separation element for separating, of the measurement light, first measurement light including information on the first spectral spectrum and second measurement light including information on the second spectral spectrum; and The first detector and the second detector respectively detect the first measurement light and the second measurement light separated from each other by the wavelength separation element.

5. The spectroscopic analysis device according to claim 4, wherein The detection unit includes a wavelength dispersion element that is disposed between the wavelength separation element and the first detector and is configured to disperse the first measurement light separated by the wavelength separation element.

6. The spectroscopic analysis device according to claim 5, wherein The wavelength dispersive element is an etalon filter.

7. The spectroscopic analysis device according to any one of claims 1 to 3, wherein The irradiation unit includes a single light source that irradiates the irradiation light having a wavelength band including the first wavelength band and the second wavelength band.

8. The spectroscopic analysis device according to claim 4, wherein The irradiation unit includes: a first light source for irradiating first irradiation light having a wavelength band equal to or less than the full width at half maximum of the resonance spectrum in the first wavelength band; and a second light source for irradiating second irradiation light having the second wavelength band. The first detector detects the first measurement light separated by the wavelength separation element in a state where the light intensity of the first measurement light changes based on the resonance spectrum.

9. The spectroscopic analysis device according to any one of claims 1 to 3, wherein The first band is included in the visible area, The second wavelength band is included in the near infrared region.

10. A spectroscopic analysis method performed by a spectroscopic analysis device for analyzing the state of a sample disposed on a film generating surface plasmons, comprising: irradiating the film with irradiation light; detecting measurement light including information of a spectroscopic spectrum based on the irradiated irradiation light, the spectroscopic spectrum including a resonance spectrum of the surface plasmon and an absorption spectrum of the sample; a step of acquiring refractive index information of the sample based on information of a first spectroscopic spectrum in a first wavelength band that generates only the resonance spectrum in the spectroscopic spectrum; a step of determining, based on the acquired refractive index information, an incident angle of the irradiation light with respect to the film at which a peak wavelength of the resonance spectrum and a peak wavelength of the absorption spectrum coincide with each other in a second spectral spectrum in the second wavelength band of the spectral spectrum that generates the resonance spectrum and the absorption spectrum; as well as A step of analyzing the state of the sample based on information of the second spectroscopic spectrum obtained based on the determined incident angle.

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