Raman microscope and its adjustment method

Abstract

A camera 63 captures a surface image of a sample. A criterion position setting processing unit 101 varies the focal position of laser light relative to the sample, which is located on a stage, and sets the focal position for which the spot area of the laser light in the surface image satisfies a prescribed first criterion as a criterion position. An assessment processing unit 102 varies the focal position in the depth direction relative to the criterion position and, on the basis of a change in the spot position of the laser light in the surface image, assesses whether or not the amount of light impinging on slits 29, 30 provided in front of a detector 50 satisfies a prescribed second criterion. An angle adjustment processing unit 103 adjusts the angle of a mirror 15 if it is assessed that the amount of light impinging on the slits 29, 30 does not satisfy the prescribed second criterion.

Description

Technical Field

[0001] The present invention relates to a Raman microscope that reflects laser light with a mirror and irradiates a sample on a stage with the laser light, spectroscopically analyzes Raman scattered light from the sample, and receives the light with a detector, and a method for adjusting the same.

Background Art

[0002] In a Raman microscope, which is an example of a Raman spectroscopic apparatus, laser light is condensed and irradiated onto a sample on a stage, and Raman scattered light from the sample is received by a detector (see, for example, Patent Document 1 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the Raman microscope as described above, the laser light from the light source can be guided to the sample on the stage by reflecting it with a mirror. Depending on the angle of this mirror, the angle of the optical axis of the laser light incident on the sample changes.

[0005] Light from the sample that has passed through a slit or a pinhole is incident on the detector. Therefore, an operator such as a user or a field engineer adjusts the focus position, the angle of the mirror, etc. so that the amount of light incident on the slit or the pinhole becomes maximum. However, it is not easy to determine whether or not the amount of light incident on the slit or the pinhole is maximum, and the operation of adjusting the stage position and the angle of the mirror based on the determination result is also complicated.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a Raman microscope capable of easily adjusting the amount of light incident on a slit or a pinhole and a method for adjusting the same.

Means for Solving the Problems

[0007] A first aspect of the present invention is a Raman microscope that reflects laser light with a mirror and irradiates a sample on a stage with the laser light, spectroscopically analyzes Raman scattered light from the sample, and receives the light with a detector, and includes a photographing unit, a reference position setting processing unit, a determination processing unit, and an angle adjustment processing unit. The photographing unit photographs a surface image of the sample. The reference position setting processing unit changes the focal position of the laser light with respect to the sample on the stage, and sets, as a reference position, the focal position at which the spot area of the laser light in the surface image satisfies a predetermined first criterion. The determination processing unit changes the focal position in the depth direction with respect to the reference position, and determines whether or not the amount of light incident on a slit or a pinhole provided in front of the detector satisfies a predetermined second criterion based on the change in the spot position of the laser light in the surface image. The angle adjustment processing unit adjusts the angle of the mirror when it is determined that the amount of light incident on the slit or the pinhole does not satisfy the predetermined second criterion.

[0008] A second aspect of the present invention is a method for adjusting a Raman microscope that reflects laser light with a mirror and irradiates the sample on the stage with the laser light, spectroscopically analyzes the Raman scattered light from the sample, and receives it with a detector, including a photographing step, a reference position setting step, a determination step, and an angle adjustment step. In the photographing step, a surface image of the sample is photographed. In the reference position setting step, the focal position of the laser light with respect to the sample on the stage is changed, and the focal position at which the spot area of the laser light in the surface image satisfies a predetermined first reference is set as the reference position. In the determination step, the focal position is changed in the depth direction with respect to the reference position, and based on the change in the spot position of the laser light in the surface image, it is determined whether the amount of light incident on a slit or a pinhole provided in front of the detector satisfies a predetermined second reference. In the angle adjustment step, when it is determined that the amount of light incident on the slit or the pinhole does not satisfy the predetermined second reference, the angle of the mirror is adjusted.

Effect of the Invention

[0009] According to the present invention, the amount of light incident on the slit or the pinhole can be easily adjusted.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 4A

Figure 4B

Figure 5

Embodiments for Carrying Out the Invention

[0011] 1. Configuration of Raman Microscope FIG. 1 is a schematic diagram showing a configuration example of a Raman microscope 1. Hereinafter, the specific configuration of the Raman microscope 1 will be described, but it is not limited to this configuration, and at least some members may be omitted, or other members may be provided.

[0012] The Raman microscope 1 includes, for example, a first laser light source 10, a second laser light source 12, a stage 25a, a spectroscopic optical system 40, a detector 50, a control unit 100, a plurality of mirrors 15, 16, 19, 21, 22, 26, a plurality of low-pass filters 17, 18, a dichroic mirror 20, an objective lens 24, a plurality of condenser lenses 27, 28, a plurality of slits 29, 30, etc. However, some of the mirrors (for example, mirrors 16, 19, 21, 22, etc.) may be omitted.

[0013] Each of the above members provided in the Raman microscope 1 is a member for performing Raman spectroscopic analysis by irradiating a sample 25 with laser light and spectroscopically detecting Raman scattered light emitted from the sample 25 excited by the laser light. Among these members, at least some of the optical members such as the plurality of mirrors 15, 16, 19, 21, 22, 26, the plurality of low-pass filters 17, 18, the dichroic mirror 20, and the plurality of condenser lenses 27, 28 may be configured such that their positions or angles can be adjusted.

[0014] Separate from the above-described respective members, the Raman microscope 1 includes a half mirror 23, an imaging lens 62, a camera 63, and the like. These members are for photographing a visible image of the sample surface where Raman scattered light is generated.

[0015] The first laser light source 10 emits a first laser beam 11. The second laser light source 12 emits a second laser beam 13 having a wavelength shorter than that of the first laser beam 11. Thus, in this embodiment, the sample 25 can be excited using two laser light sources 10 and 12 that emit laser beams 11 and 13 having different wavelengths, respectively. However, the number of laser light sources provided in the Raman microscope 1 is not limited to two, and may be one or three or more.

[0016] The laser light source can be constituted by a laser oscillator such as a diode laser-excited solid laser, a helium-neon laser, a titanium sapphire laser, or a Nd:YAG laser. Further, in the case of a configuration in which the laser light from the laser oscillator is guided by a light guide such as an optical fiber, an emission tube provided at the tip of the optical fiber may constitute the laser light source.

[0017] The sample 25 is supported on a stage 25a. In this embodiment, depending on the sample 25, either the first laser beam 11 or the second laser beam 13 can be irradiated onto the sample 25. The sample 25 excited by the irradiation of the first laser beam 11 emits first Raman scattered light 31. On the other hand, the sample 25 excited by the irradiation of the second laser beam 13 emits second Raman scattered light 33.

[0018] Since the efficiency of Raman scattering increases as the excitation wavelength becomes shorter, when increasing the intensity of Raman scattered light, it is preferable to irradiate the sample 25 with the second laser beam 13 instead of the first laser beam 11. On the other hand, when the fluorescence emitted from the sample 25 is too strong when irradiating the sample 25 with the second laser beam 13, it is preferable to irradiate the sample 25 with the first laser beam 11 instead of the second laser beam 13.

[0019] The first laser light 11 emitted from the first laser light source 10 is reflected by the mirrors 15 and 16 and enters the low-pass filter 17. The low-pass filter 17 reflects the first laser light 11 and transmits the first Raman scattered light 31. Therefore, the first laser light 11 incident on the low-pass filter 17 is reflected by the low-pass filter 17 and enters the dichroic mirror 20.

[0020] The dichroic mirror 20 transmits the first laser light 11 and the first Raman scattered light 31 and reflects the second laser light 13 and the second Raman scattered light 33. Therefore, the first laser light 11 incident on the dichroic mirror 20 passes through the dichroic mirror 20, is sequentially reflected by the mirrors 21 and 22, and then is irradiated onto the sample 25 through the half mirror 23 and the objective lens 24. At this time, the first laser light 11 is condensed by passing through the objective lens 24 and is irradiated onto the surface of the sample 25 as a spot. The focal position of the first laser light 11 condensed by the objective lens 24 is not limited to the surface of the sample 25 and may be located inside or outside the sample 25.

[0021] The second laser light 13 emitted from the second laser light source 12 is reflected by the mirrors 15 and 16 and enters the low-pass filter 18. The low-pass filter 18 reflects the second laser light 13 and transmits the second Raman scattered light 33. Therefore, the second laser light 13 incident on the low-pass filter 18 is reflected by the low-pass filter 18, is sequentially reflected by the mirror 19, the dichroic mirror 20, and the mirrors 21 and 22, and then is irradiated onto the sample 25 through the half mirror 23 and the objective lens 24. At this time, the second laser light 13 is condensed by passing through the objective lens 24 and is irradiated onto the surface of the sample 25 as a spot. The focal position of the second laser light 13 condensed by the objective lens 24 is not limited to the surface of the sample 25 and may be located inside or outside the sample 25.

[0022] The first Raman scattered light 31 radiated from the sample 25 irradiated with the first laser light 11 has a wavelength longer than that of the first laser light 11. The first Raman scattered light 31 passes through the objective lens 24, is sequentially reflected by the mirrors 22 and 21, then passes through the dichroic mirror 20 and the low-pass filter 17, and is reflected by the mirror 26. The first Raman scattered light 31 reflected by the mirror 26 is condensed by the condenser lens 27, then passes through the slit 29, and enters the spectroscopic optical system 40. However, a pinhole may be provided instead of the slit 29, and the first Raman scattered light 31 may enter the spectroscopic optical system 40 through the pinhole.

[0023] The second Raman scattered light 33 radiated from the sample 25 irradiated with the second laser light 13 has a wavelength longer than that of the second laser light 13. Also, the second Raman scattered light 33 has a wavelength shorter than that of the first Raman scattered light 31. The second Raman scattered light 33 passes through the objective lens 24, is sequentially reflected by the mirrors 22, 21, the dichroic mirror 20 and the mirror 19, then passes through the low-pass filter 18, and is reflected by the mirror 26. The second Raman scattered light 33 reflected by the mirror 26 is condensed by the condenser lens 28, then passes through the slit 30, and enters the spectroscopic optical system 40. However, a pinhole may be provided instead of the slit 30, and the second Raman scattered light 33 may enter the spectroscopic optical system 40 through the pinhole.

[0024] The spectroscopic optical system 40 includes, for example, a collimator lens, a spectroscope, and a condenser optical element (none of which are shown). The spectroscope includes a spectroscopic optical element such as a grating or a prism. The first Raman scattered light 31 and the second Raman scattered light 33 entering the spectroscopic optical system 40 are spectroscopically separated by different spectroscopic optical elements, and the first Raman scattered light 31 and the second Raman scattered light 33 separated for each wavelength are condensed by the condenser optical element and received by the detector 50.

[0025] As the detector 50, for example, a CCD (Charge Coupled Device) detector can be mentioned. The detector 50 includes a plurality of light detection elements, and outputs a signal corresponding to the light reception intensity of the first Raman scattered light 31 or the second Raman scattered light 33 in each light detection element. The electrical signal output from the detector 50 is processed by a control unit 100 electrically connected to the detector 50.

[0026] The camera 63 is an imaging unit that captures a surface image of the sample 25. The light from the sample surface where Raman scattered light is generated passes through the objective lens 24, is reflected by the half mirror 23, and is imaged on the light receiving surface 64 of the camera 63 by the imaging lens 62. The camera 63 includes, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, and is configured to be able to capture a still image or a moving image of the sample 25. The camera 63 can capture all or at least one of a bright field image, a dark field image, a phase contrast image, a fluorescence image, and a polarized light microscope image of the sample 25.

[0027] In this embodiment, before performing Raman spectroscopic analysis, the angle of the mirror 15 is adjusted so that the amount of Raman scattered light from the sample 25 incident on the slits 29 and 30 provided in front of the detector 50 is maximized, thereby adjusting (optical axis adjustment) the Raman microscope 1. At this time, on the stage 25a, instead of the actual sample to be analyzed, an adjustment sample 25 with a flat surface is supported. The adjustment sample 25 is irradiated with laser light (the first laser light 11 or the second laser light 13), and an image of the laser light spot on the sample surface is captured by the camera 63. The adjustment of the Raman microscope 1 is performed based on the area (spot area) and position (spot position) of the laser light spot in the surface image of the sample 25 captured by the camera 63.

[0028] 2. Electrical Configuration of Raman Microscope FIG. 2 is a block diagram showing an example of the electrical configuration of the Raman microscope 1. In addition to the respective parts described above, the Raman microscope 1 includes a storage unit 200, a display unit 300, and the like.

[0029] The control unit 100 has a configuration including, for example, a CPU (Central Processing Unit). When the CPU executes a program, the control unit 100 functions as a reference position setting processing unit 101, a determination processing unit 102, an angle adjustment processing unit 103, a light amount adjustment processing unit 104, a Raman analysis processing unit 105, and the like. The reference position setting processing unit 101, the determination processing unit 102, the angle adjustment processing unit 103, and the light amount adjustment processing unit 104 execute processes for adjusting the Raman microscope 1 before Raman spectroscopic analysis.

[0030] The reference position setting processing unit 101 performs a process of setting a reference position of the focal position of the laser beam based on the spot area of the laser beam in the surface image of the sample 25 (sample for adjustment) photographed by the camera 63. Specifically, as the stage 25a is moved in a predetermined range in the vertical direction, the focal position of the laser beam on the sample 25 on the stage 25a changes along the depth direction, which is the irradiation direction (optical axis direction) of the laser beam with respect to the sample 25. At this time, as the focal position of the laser beam changes, the spot area of the laser beam in the surface image of the sample 25 changes.

[0031] The reference position setting processing unit 101 calculates the change in the spot area by calculation, and sets the focal position at which the spot area becomes the minimum value as the reference position. However, the "minimum value" is an example of a "predetermined first reference", and the focal position at which the spot area satisfies other references may be set as the reference position. The position information of the reference position set by the reference position setting processing unit 101 is stored in the storage unit 200. The storage unit 200 includes a non-volatile memory such as a hard disk, for example.

[0032] FIGS. 3A to 3C are diagrams showing an example of the surface image of the sample 25, and show the change in the spot area when the focal position of the laser beam on the sample 25 on the stage 25a is changed.

[0033] When setting the reference position of the focal position of the laser beam, the surface image of the sample 25 is a microscopic image taken with both the exposure time and the gain of the camera 63 set to the minimum values. Also, the spot area of the laser beam in the surface image of the sample 25 can be calculated by determining the bright part as the spot when binarizing the surface image of the sample 25 and obtaining the area of the bright part.

[0034] When the focal position of the laser beam is at the reference position (optimal position), as shown in FIG. 3A, the spot area becomes the minimum value. On the other hand, when the focal position of the laser beam is shifted in the depth direction with respect to the reference position, as shown in FIG. 3B, the spot area becomes larger than that in the case of FIG. 3A. Further, when the focal position of the laser beam is further shifted in the depth direction with respect to the reference position from the state of FIG. 3B, as shown in FIG. 3C, in addition to the intensity of the laser beam becoming weak, the spot of the laser beam does not fit within the surface image of the sample 25, so the value calculated as the spot area becomes smaller.

[0035] Referring to FIG. 2 again, the determination processing unit 102 performs a process of determining whether or not the amount of light incident on the slits 29 and 30 provided in front of the detector 50 is maximum based on the spot position of the laser beam in the surface image of the sample 25 (adjustment sample) taken by the camera 63. Specifically, as the stage 25a is moved in a predetermined range in the vertical direction, the focal position of the laser beam changes in the depth direction with respect to the reference position. However, instead of determining whether or not the amount of light incident on the slits 29 and 30 is maximum, it may be determined whether or not the amount of light satisfies another reference (predetermined second reference).

[0036] If the amount of light incident on the slits 29 and 30 is not maximum, when the focal position of the laser beam with respect to the sample 25 on the stage 25a is changed along the depth direction, the spot position of the laser beam in the surface image of the sample 25 changes. The determination processing unit 102 calculates the change in the spot position (change in the centroid position of the spot) by calculation and compares the amount of change with a threshold value to determine whether or not the amount of light incident on the slits 29 and 30 is maximum.

[0037] FIG. 4A and FIG. 4B are diagrams showing an example of the surface image of the sample 25, and showing the change in the spot position when the angle of the mirror is changed.

[0038] When the amount of light incident on the slits 29 and 30 is not maximum, as shown in FIG. 4A, when the focal position of the laser beam with respect to the sample 25 on the stage 25a is changed along the depth direction, the spot position deviates from the reference position. On the other hand, when the amount of light incident on the slits 29 and 30 is maximum, as shown in FIG. 4B, even if the focal position of the laser beam is changed along the depth direction, the spot position does not deviate from the reference position.

[0039] Referring to FIG. 2 again, when it is determined in the determination processing unit 102 that the amount of light incident on the slits 29 and 30 is not maximum, the angle adjustment processing unit 103 performs a process of adjusting the angle of the mirror 15. The angle of the mirror 15 can be adjusted, for example, by controlling the applied voltage to a piezo element (not shown). However, the mechanism is not limited to the one using a piezo element, and the angle of the mirror 15 can be adjusted using any other arbitrary mechanism.

[0040] As shown in FIG. 1, the laser beam before being irradiated onto the sample 25 is incident on the mirror 15, but the light from the sample 25 is not incident. Therefore, by adjusting the angle of the mirror 15, the angle of the optical axis of the laser beam incident on the sample 25 changes, and as a result, the angle of the light incident on the detector 50 from the sample 25 also changes. In the present embodiment, by adjusting the angle of the mirror 15, the amount of light from the sample 25 incident on the slits 29 and 30 can be adjusted to be maximum. The adjustment amount (change amount) of the angle of the mirror 15 at this time can be calculated based on the change amount of the spot position of the laser beam during the determination process.

[0041] After the processing by the angle adjustment processing unit 103, the light quantity adjustment processing unit 104 performs processing to adjust the light quantity received by the detector 50. Specifically, the optical axis of the light incident on the detector 50 is adjusted by adjusting the angle of the mirror 26 so that the light quantity received by the detector 50 becomes maximum. The angle of the mirror 26 can be adjusted, for example, by controlling the applied voltage to a piezo element (not shown). However, it is not limited to the mechanism using the piezo element, and the angle of the mirror 26 can be adjusted using any other mechanism. Also, the angle of the mirror 26 may not be adjusted so that the light quantity received by the detector 50 becomes maximum, and the angle of the mirror 26 may be adjusted so that the light quantity satisfies another criterion (a predetermined third criterion).

[0042] As shown in FIG. 1, light from the sample 25 is incident on the mirror 26, and the light reflected by the mirror 26 is detected by the detector 50 through the slits 29 and 30. Therefore, by adjusting the angle of the mirror 26, the light quantity passing through the slits 29 and 30 changes, and as a result, the light quantity received by the detector 50 also changes.

[0043] The Raman analysis processing unit 105 executes processing for performing Raman spectroscopic analysis on the sample 25 on the stage 25a. Specifically, a Raman spectrum is acquired based on the detection signal from the detector 50. The Raman spectrum obtained by Raman spectroscopic analysis may be displayed on the display unit 300 by the Raman analysis processing unit 105. The display unit 300 is configured to include, for example, a liquid crystal display, but is not limited thereto.

[0044] 3. Adjustment Processing of Raman Microscope FIG. 5 is a flowchart for explaining the adjustment processing of the Raman microscope 1. The adjustment processing of the Raman microscope 1 shown in FIG. 5 is executed by the control unit 100 before Raman spectroscopic analysis in order to perform Raman spectroscopic analysis well. The adjustment processing may be automatically started under the control of the control unit 100, or may be started based on an operation of an operation unit (not shown) by an operator such as a user or a field engineer.

[0045] When the adjustment process of the Raman microscope 1 is started, while the sample 25 is irradiated with laser light, the camera 63 starts taking a surface image of the sample 25 (step S1: imaging step). After that, by moving the stage 25a, the focal position of the laser light with respect to the sample 25 on the stage 25a is changed along the depth direction, and the focal position at which the spot area of the laser light in the surface image of the sample 25 becomes the minimum value is set as the reference position (steps S2 to S3: reference position setting step).

[0046] When the reference position is set, by moving the stage 25a again, the focal position is changed in the depth direction with respect to the reference position, and it is determined whether or not the spot position of the laser light in the surface image of the sample 25 has changed (steps S4 to S5: determination step). Then, when the spot position of the laser light has changed (YES in step S5), it is determined that the amount of light incident on the slits 29 and 30 is not maximum, and the angle of the mirror 15 is adjusted (step S6: angle adjustment step).

[0047] In this case, after the angle of the mirror 15 is adjusted, steps S5 to S6 are repeated until it is determined that the spot position has not changed (until NO in step S5), that is, until it is determined that the amount of light incident on the slits 29 and 30 is maximum.

[0048] When it is determined that the spot position has not changed (NO in step S5), that is, when it is determined that the amount of light incident on the slits 29 and 30 is maximum and more precise adjustment is required (YES in step S7), similar to steps S4 to S6, by moving the stage 25a, the focal position of the laser light with respect to the sample 25 on the stage 25a is changed along the depth direction, and it is re-determined whether or not the spot position of the laser light in the surface image of the sample 25 has changed. Then, when the spot position of the laser light has changed, it is re-determined that the amount of light incident on the slits 29 and 30 is not maximum, and the angle of the mirror 15 is readjusted. Thereby, fine adjustment of the mirror 15 is performed. However, the fine adjustment of the mirror 15 may be omitted.

[0049] After the fine adjustment of the mirror 15 (NO in step S7), similar to the case of steps S2 to S3, the stage 25a is moved to change the focal position of the laser beam along the depth direction, and the focal position at which the spot area of the laser beam in the surface image of the sample 25 becomes the minimum value is reset to the reference position (steps S8 to S9). Thereby, the fine adjustment of the reference position is performed. However, the fine adjustment of the reference position may be omitted.

[0050] Thereafter, by adjusting the angle of the mirror 26, the optical axis of the light incident on the detector is adjusted so that the amount of light received by the detector 50 becomes maximum (step S9: light amount adjustment step).

[0051] 4. Aspect Those skilled in the art will understand that the above-described plurality of exemplary embodiments are specific examples of the following aspects.

[0052] (Item 1) A Raman microscope according to one aspect is a Raman microscope that reflects a laser beam with a mirror, irradiates the sample on the stage with the laser beam, disperses the Raman scattered light from the sample, and receives it with a detector, an imaging unit that captures a surface image of the sample, a reference position setting processing unit that changes the focal position of the laser beam with respect to the sample on the stage and sets the focal position at which the spot area of the laser beam in the surface image satisfies a predetermined first reference as the reference position, a determination processing unit that changes the focal position in the depth direction with respect to the reference position and determines whether the amount of light incident on a slit or a pinhole provided in front of the detector satisfies a predetermined second reference based on the change in the spot position of the laser beam in the surface image, and may include an angle adjustment processing unit that adjusts the angle of the mirror when it is determined that the amount of light incident on the slit or the pinhole does not satisfy the predetermined second reference.

[0053] According to the Raman microscope described in claim 1, after setting the reference position of the focal position of the laser beam, the focal position is changed in the depth direction with respect to the reference position, and based on the change in the spot position of the laser beam in the surface image of the sample, it can be determined whether the amount of light incident on the slit or pinhole satisfies a predetermined second criterion. By adjusting the angle of the mirror based on this determination result, the amount of light incident on the slit or pinhole can be easily adjusted.

[0054] (Claim 2) In the Raman microscope according to claim 1, The process by the angle adjustment processing unit may be repeatedly performed until the determination processing unit determines that the amount of light incident on the slit or pinhole satisfies the predetermined second criterion.

[0055] According to the Raman microscope described in claim 2, even if the amount of light incident on the slit or pinhole does not satisfy the predetermined second criterion with only one angle adjustment of the mirror, by repeatedly adjusting the angle of the mirror, the amount of light incident on the slit or pinhole can be adjusted to surely satisfy the predetermined second criterion. After the determination processing unit determines that the amount of light incident on the slit or pinhole satisfies the predetermined second criterion, re-determination by the determination processing unit and re-processing by the angle adjustment processing unit may be performed.

[0056] (Claim 3) In the Raman microscope according to claim 1 or 2, After the process by the angle adjustment processing unit is performed, the reference position may be set again by the reference position setting processing unit.

[0057] According to the Raman microscope described in claim 3, after adjusting the angle of the mirror so that the amount of light incident on the slit or pinhole satisfies the predetermined second criterion, the reference position of the focal position of the laser beam can be finely adjusted.

[0058] (Claim 4) In the Raman microscope according to any one of claims 1 to 3, After the processing by the angle adjustment processing unit, a light amount adjustment processing unit may be further provided to adjust the optical axis of the light incident on the detector so that the light amount received by the detector satisfies a predetermined third reference.

[0059] According to the Raman microscope described in claim 4, after adjusting the angle of the mirror so that the light amount incident on the slit or pinhole satisfies a predetermined second reference, the intensity of the light incident on the detector can be adjusted.

[0060] (Claim 5) A method for adjusting a Raman microscope according to one aspect is a method for adjusting a Raman microscope that reflects laser light with a mirror, irradiates the sample on the stage with the laser light, spectroscopically analyzes Raman scattered light from the sample, and receives it with a detector, a photographing step of photographing a surface image of the sample, a reference position setting step of changing the focal position of the laser light with respect to the sample on the stage and setting the focal position at which the spot area of the laser light in the surface image satisfies a predetermined first reference as the reference position, a determination step of changing the focal position in the depth direction with respect to the reference position and determining whether or not the light amount incident on a slit or pinhole provided in front of the detector satisfies a predetermined second reference based on the change in the spot position of the laser light in the surface image, and may include an angle adjustment step of adjusting the angle of the mirror when it is determined that the light amount incident on the slit or pinhole does not satisfy the predetermined second reference.

[0061] According to the method for adjusting a Raman microscope described in claim 5, after setting the reference position of the focal position of the laser light, the focal position is changed in the depth direction with respect to the reference position, and based on the change in the spot position of the laser light in the surface image of the sample, it can be determined whether or not the light amount incident on the slit or pinhole satisfies a predetermined second reference. By adjusting the angle of the mirror based on this determination result, the light amount incident on the slit or pinhole can be easily adjusted.

[0062] (Item 6) In the method for adjusting a Raman microscope according to Item 5, the angle adjustment step may be repeatedly performed until it is determined by the determination step that the amount of light incident on the slit or pinhole satisfies the predetermined second criterion.

[0063] According to the method for adjusting a Raman microscope according to Item 6, even if the amount of light incident on the slit or pinhole does not satisfy the predetermined second criterion with only one angle adjustment of the mirror, the angle adjustment of the mirror is repeatedly performed, so that the amount of light incident on the slit or pinhole can be adjusted to surely satisfy the predetermined second criterion. After it is determined by the determination step that the amount of light incident on the slit or pinhole satisfies the predetermined second criterion, re-determination by the determination step and reprocessing by the angle adjustment step may be performed.

[0064] (Item 7) In the method for adjusting a Raman microscope according to Item 5 or 6, after the angle adjustment step is performed, the reference position may be reset by the reference position setting step.

[0065] According to the Raman microscope according to Item 7, after adjusting the angle of the mirror so that the amount of light incident on the slit or pinhole satisfies the predetermined second criterion, the reference position of the focal position of the laser beam can be finely adjusted.

[0066] (Item 8) In the method for adjusting a Raman microscope according to any one of Items 5 to 7, after the angle adjustment step is performed, the method may further include a light amount adjustment step of adjusting the optical axis of the light incident on the detector so that the amount of light received by the detector satisfies a predetermined third criterion.

[0067] According to the method for adjusting a Raman microscope according to Item 8, after adjusting the angle of the mirror so that the amount of light incident on the slit or pinhole satisfies the predetermined third criterion, the intensity of the light incident on the detector can be adjusted.

Explanation of Symbols

[0068] 1 Raman microscope 10 First laser light source 11 First laser light 12 Second laser light source 13 Second laser light 15, 16, 26 Mirror 25 Sample 25a Stage 31 First Raman scattered light 33 Second Raman scattered light 50 Detector 63 Camera 100 Control unit 101 Reference position setting processing unit 102 Judgment processing unit 103 Angle adjustment processing unit 104 Light quantity adjustment processing unit

Claims

1. A Raman microscope that reflects laser light with a mirror, irradiates a sample on a stage with the laser light, disperses Raman scattered light from the sample, and receives the light with a detector, comprising: an imaging unit that captures a surface image of the sample; along the depth direction, which is the irradiation direction of the laser light on the sample, the focal position of the laser light on the sample on the stage is changed, the change in the spot area of the laser light in the surface image of the sample captured by the imaging unit is calculated by arithmetic operation, and a reference position setting processing unit that sets the focal position at which the spot area becomes a minimum value as a reference position; the focal position is changed in the depth direction with respect to the reference position, the change in the spot position of the laser light in the surface image of the sample captured by the imaging unit is calculated by arithmetic operation, and by comparing the amount of change with a threshold value, when it is determined that the spot position does not deviate from the reference position, a determination processing unit that determines that the amount of light incident on a slit or a pinhole provided in front of the detector is maximum; an angle adjustment processing unit that adjusts the angle of the mirror when it is determined by the determination processing unit that the spot position has deviated from the reference position and thus the amount of light incident on the slit or the pinhole is not maximum. A Raman microscope.

2. The Raman microscope according to claim 1, wherein the processing by the angle adjustment processing unit is repeatedly performed until it is determined by the determination processing unit that the spot position does not deviate from the reference position and thus the amount of light incident on the slit or the pinhole is maximum.

3. The Raman microscope according to claim 1, wherein the reference position is reset by the reference position setting processing unit after the processing by the angle adjustment processing unit is performed.

4. The Raman microscope according to claim 1, further comprising a light amount adjustment processing unit that adjusts the optical axis of the light incident on the detector so that the amount of light received by the detector becomes maximum after the processing by the angle adjustment processing unit is performed.

5. An adjustment method for a Raman microscope that reflects laser light with a mirror, irradiates a sample on a stage with the laser light, disperses Raman scattered light from the sample, and receives the light with a detector, comprising: an imaging step of capturing a surface image of the sample; Along the depth direction, which is the irradiation direction of the laser beam with respect to the sample, the focal position of the laser beam with respect to the sample on the stage is changed, the change in the spot area of the laser beam in the surface image of the sample taken in the imaging step is calculated by arithmetic operation, and a reference position setting step of setting the focal position at which the spot area becomes a minimum value as a reference position; The focal position is changed in the depth direction with respect to the reference position, the change in the spot position of the laser beam in the surface image of the sample taken in the imaging step is calculated by arithmetic operation, and by comparing the amount of change with a threshold value, when it is determined that the spot position does not deviate from the reference position, a determination step of determining that the amount of light incident on the slit or pinhole provided in front of the detector is maximum; An adjustment method of a Raman microscope, comprising an angle adjustment step of adjusting the angle of the mirror when it is determined in the determination step that the spot position deviates from the reference position, and thus it is determined that the amount of light incident on the slit or pinhole is not maximum.

6. The adjustment method of a Raman microscope according to claim 5, wherein the angle adjustment step is repeatedly performed until it is determined in the determination step that the amount of light incident on the slit or pinhole is maximum because it is determined that the spot position does not deviate from the reference position.

7. The adjustment method of a Raman microscope according to claim 5, wherein the reference position is reset again by the reference position setting step after the angle adjustment step is performed.

8. The adjustment method of a Raman microscope according to claim 5, further comprising a light amount adjustment step of adjusting the optical axis of the light incident on the detector so that the amount of light received by the detector becomes maximum after the angle adjustment step is performed.

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