JP2012242245A - Raman scattering light detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Raman scattering light detection device capable of increasing Raman scattering light without allowing the poor oscillation of a laser and the damage of a sample to occur.SOLUTION: Laser light (an optical beam) is made incident from a laser light source (an incident part) 2 to a hemispherical prism (a translucent member) 1 having a sample surface 11. The laser light is reflected against the sample surface 11, reflected against a mirror (a reflection body) 31, and reflected against the sample surface 11 again. The reflection angle of the mirror 31 is adjusted not to allow optical paths to be coincident before/after the reflection, so that the laser light is reflected at a position different from the preceding time on the sample surface 11. Subsequently, the laser light is repetitively reflected by varying the reflection positions between a spherical surface part 12 with mirror coating performed thereon and the sample surface 11. The laser light is not made incident to the laser light source 2 thereby to prevent the poor oscillation of a laser. The laser light is not converged on one point in the sample S, thereby to prevent the damage of the sample S. The laser light is reflected against the sample surface 11 multiple times, so that the Raman scattering light is increased.

Description

  The present invention relates to a Raman scattered light detection apparatus that reflects excitation light on the back side of a sample surface in contact with a sample and detects Raman scattered light generated from the sample.

  Conventionally, Raman spectroscopic analysis has been used as a method for performing non-destructive identification of a substance contained in a sample or estimation of a distribution of a specific substance. In Raman spectroscopic analysis, a method is used in which a sample is brought into contact with a translucent member, excitation light is reflected from the surface of the translucent member that contacts the sample, and Raman scattered light emitted in a direction different from the reflected light is detected. ing. In particular, there is a method in which excitation light is totally reflected at a contact surface with a sample, and Raman scattered light generated from the sample is detected by evanescent light generated by total reflection. Since evanescent light excites only the surface of the sample, Raman spectroscopic analysis of the sample surface can be performed.

  By the way, since the Raman scattered light is weak, a technique for increasing the Raman scattered light has been developed. Patent Document 1 discloses a technique in which laser light is used as excitation light, the laser light that has excited the sample is reflected, and is incident on the sample again. When the excitation light enters the sample again, the generated Raman scattered light increases.

JP-A 61-20841

  However, in the technique disclosed in Patent Document 1, when the laser light used as excitation light is reflected and reenters the sample, the forward path and the return path of the laser light coincide with each other. Incident light may cause a laser oscillation failure in the laser light source. In addition, the excitation light is incident on the same position on the sample, and the excitation light may be concentrated on one point on the sample and the sample may be damaged.

  The present invention has been made in view of such circumstances, and an object of the present invention is to emit Raman scattered light without causing a laser oscillation failure by making excitation light incident multiple times while changing the optical path. An object of the present invention is to provide a Raman scattered light detection device that can be increased and that is less likely to damage a sample.

  A Raman scattered light detection apparatus according to the present invention has a light-transmitting member having a flat sample surface with which an arbitrary sample is contacted, and a light beam is incident on the light-transmitting member so as to be reflected by the sample surface. In a Raman scattered light detection apparatus comprising an incident portion and means for detecting Raman scattered light generated on the sample by the light beam, the light beam reflected by the sample surface is reflected again and incident on the sample surface And reflecting means for reflecting at a position different from the position previously reflected on the sample surface on the sample surface.

  In the present invention, the Raman scattered light detection apparatus receives a light beam from an incident portion with respect to a translucent member having a sample surface in contact with the sample, and reflects the light beam on the sample surface in the translucent member. The light beam is reflected again, and the light beam is reflected at other positions on the sample surface. By reflecting the light beam so that the light beam is reflected at other positions on the sample surface, the optical path of the light beam is changed, and the light beam does not enter the incident portion. In addition, since the light beam is reflected a plurality of times at different positions on the sample surface, the light beam is not concentrated and irradiated on one point on the sample.

  In the Raman scattered light detection apparatus according to the present invention, the reflecting means includes means for reflecting a light beam directed toward the incident portion.

  In the present invention, the Raman scattered light detection device reflects the light beam that is reflected by the sample surface and then directed to the incident portion. The reflected light beam is incident on the sample surface, and the reflection of the light beam on the sample surface is repeated.

  In the Raman scattered light detection apparatus according to the present invention, the reflection means reflects the light beam reflected by the sample surface and emitted from the light transmitting member so as to be incident on the light transmitting member by changing an optical path. It includes the body.

  In the present invention, the Raman scattered light detection device reflects the light beam emitted from the translucent member with the reflector so as to be incident on the translucent member while changing the optical path.

  The Raman scattered light detection apparatus according to the present invention is characterized in that the reflector is configured to be capable of adjusting a light reflection angle.

  In the present invention, the reflection angle of the reflector that reflects the light beam can be appropriately adjusted so that the optical path of the light beam can be appropriately changed.

  In the Raman scattered light detection device according to the present invention, the reflector is configured to be swingable so that the reflection angle of light continuously changes, and further includes a drive unit that swings the reflector. It is characterized by.

  In the present invention, the reflector that reflects the light beam swings to change the high-speed optical path to be reflected.

  In the Raman scattered light detection device according to the present invention, the translucent member is a hemispherical prism having a flat surface as the sample surface, and the reflecting means reflects light inside the hemispherical prism. A mirror coating part obtained by mirror coating the spherical part of the hemispherical prism except for a part is included.

  In the present invention, the translucent member is a hemispherical prism, and a mirror coating portion is provided on the spherical portion of the hemispherical prism, and the light beam is repeatedly reflected between the sample surface and the mirror coating portion.

  In the present invention, the intensity of Raman scattered light can be increased without increasing the intensity of the light beam by repeatedly reflecting the light beam and making the light beam incident on the sample a plurality of times. Further, since the light beam does not enter the incident portion, no laser light oscillation failure occurs in the incident portion. Further, the sample is not damaged due to the light beam concentrating on one point on the sample. Therefore, the present invention has excellent effects such as generation of Raman scattered light from the sample a plurality of times without increasing laser oscillation and damage to the sample, thereby increasing the detectable Raman scattered light.

1 is a schematic diagram illustrating a configuration of a Raman scattered light detection apparatus according to Embodiment 1. FIG. It is the schematic which shows the structure of the Raman scattered light detection apparatus which concerns on Embodiment 2. FIG. FIG. 6 is a schematic diagram illustrating a configuration of a Raman scattered light detection apparatus according to a third embodiment. It is the schematic which shows the structure of the Raman scattered light detection apparatus which concerns on Embodiment 4. FIG. FIG. 10 is a schematic diagram illustrating a configuration of a Raman scattered light detection device according to a fifth embodiment. FIG. 10 is a schematic diagram illustrating a configuration of a Raman scattered light detection apparatus according to a sixth embodiment. FIG. 10 is a schematic diagram illustrating a configuration of a Raman scattered light detection device according to a seventh embodiment. FIG. 10 is a schematic diagram illustrating a configuration of a Raman scattered light detection device according to an eighth embodiment.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
(Embodiment 1)
FIG. 1 is a schematic diagram showing the configuration of the Raman scattered light detection apparatus according to the first embodiment. The Raman scattered light detection apparatus includes a hemispherical prism 1 on which a sample S is placed, a laser light source (incident part) 2 that emits laser light (light beam) L, and a mirror (reflector) 31. I have. The hemispherical prism 1 is made of a translucent material such as quartz glass, and is formed in a hemispherical shape obtained by cutting a sphere along a plane passing through the center of the sphere. The hemispherical prism 1 corresponds to the translucent member in the present invention. Further, the hemispherical prism 1 is arranged with the flat surface portion on the upper side, and the flat surface portion is a sample surface 11 on which the sample S is placed. The sample surface 11 includes a spherical center of the spherical portion 12 of the hemispherical prism 1 and has a circular shape with the spherical center as the center of a circle. The three-dimensional shape of the hemispherical prism 1 is a shape obtained by rotating the cross-sectional view of the hemispherical prism 1 shown in FIG. 1 about an axis passing through the center of the sphere and orthogonal to the sample surface 11.

  The laser light source 2 is disposed at a position where the laser light is incident on the hemispherical prism 1 so as to intersect the spherical surface portion 12 of the hemispherical prism 1. For example, the laser light source 2 is arranged on a straight line connecting the center of the sample surface 11 and one point on the spherical surface portion 12. The laser light incident on the hemispherical prism 1 is reflected by the sample surface 11 inside the hemispherical prism 1. In FIG. 1, the laser beam is indicated by a solid line with an arrow. The laser light source 2 is preferably arranged so that the laser light is incident on the hemispherical prism 1 while satisfying the condition that the laser light is totally reflected by the sample surface 11. The configuration of the Raman scattered light detection device may be a configuration in which laser light from the laser light source 2 is incident on the hemispherical prism 1 via an optical system.

  The laser light incident on the hemispherical prism 1 from the laser light source 2 and reflected by the sample surface 11 intersects the spherical portion 12 and is emitted from the hemispherical prism 1. The mirror 31 is disposed at a position where the laser beam emitted from the hemispherical prism 1 enters. The laser light incident on the mirror 31 is reflected by the mirror 31, reenters the hemispherical prism 1, and is reflected again by the sample surface 11. The mirror 31 is configured to be able to adjust the reflection angle of the laser beam with respect to the hemispherical prism 1 by a user operation. The reflection angle of the mirror 31 is adjusted in advance so that the forward and backward paths of the laser light before and after the reflection do not coincide. Since the forward path and the return path of the laser light reflected by the mirror 31 do not coincide with each other, the laser light reflected by the mirror 31 and incident on the hemispherical prism 1 is incident at a different position at an angle different from that at the time of emission. For this reason, the optical path of the laser beam in the hemispherical prism 1 is also different from that at the time of emission, and the laser beam is reflected at a position different from the previously reflected position on the sample surface 11.

  On the outer side of the spherical surface portion 12 of the hemispherical prism 1, a mirror coating portion 13 is formed by applying mirror coating. However, mirror coating is not applied to the entrance 14 where the laser light is incident from the laser light source 2 and the exit 15 where the laser light reflected by the mirror 31 is emitted. The laser beam reflected by the mirror 31 enters the hemispherical prism 1 from the emission port 15. The mirror coating portion 13 is for reflecting the laser light inside the hemispherical prism 1. The laser beam reflected again by the sample surface 11 is incident on the spherical surface portion 12 and is reflected by the spherical surface portion 12 by the mirror coating portion 13. Since the position where the laser beam is reflected by the sample surface 11 immediately before is a position shifted from the center of the sample surface 11, the forward and backward paths of the laser beam before and after being reflected by the spherical surface portion 12 do not coincide with each other. For this reason, the laser beam reflected by the spherical surface portion 12 is reflected at a position different from the previously reflected position on the sample surface 11. In this way, the laser light is repeatedly reflected a plurality of times between the sample surface 11 and the spherical surface portion 12. In particular, when the condition that the laser beam is totally reflected at the sample surface 11 is satisfied, the laser beam is not emitted from the sample surface 11 and is repeatedly reflected with high efficiency. The position where the laser beam is reflected on the sample surface 11 is different each time. Finally, the laser light is attenuated in the hemispherical prism 1 or emitted from the sample surface 11 to the outside of the hemispherical prism 1. The mirror 31 and the mirror coating part 13 correspond to the reflecting means in the present invention.

  The sample S is placed on the sample surface 11 of the hemispherical prism 1. For example, the sample S is placed at the center of the sample surface 11. The sample S is assumed to be a transparent substance. The laser beam is reflected on the back side of the sample surface 11 when viewed from the sample S. When the laser light is reflected by the sample surface 11 in the hemispherical prism 1, a part of the laser light enters the sample S, and the entered laser light acts on the sample S as excitation light, and Raman scattered light is generated. . For example, when the laser beam is totally reflected by the sample surface 11, evanescent light is generated on the sample surface 11, and the evanescent light penetrates into the sample S in contact with the sample surface 11, and is caused by the interaction between the evanescent light and the sample S. Raman scattered light is generated. The generated Raman scattered light passes through the transparent sample S and is emitted out of the sample S. In FIG. 1, Raman scattered light is indicated by a broken line with an arrow.

  The Raman scattered light detection apparatus further includes a condensing lens 41 that collects the Raman scattered light emitted through the sample S and a detection unit 42 that detects the collected Raman scattered light. In addition to the condenser lens 41, various optical components such as various lenses and mirrors may be provided between the hemispherical prism 1 and the detection unit 42. The detection unit 42 includes a spectroscope, an optical sensor, and the like, and detects the wavelength and intensity of the Raman scattered light generated in the sample S. The detection result of the detection unit 42 is output as an electric signal to the outside, and the Raman spectroscopic analysis of the sample S is performed by an analyzer (not shown). In particular, when the laser beam is totally reflected by the sample surface 11, Raman spectroscopic analysis of the surface layer portion of the sample S can be performed.

  The Raman scattered light detection apparatus having the above configuration reflects a laser beam on the sample surface 11 a plurality of times inside the hemispherical prism 1 with the sample S placed on the sample surface 11 of the hemispherical prism 1. The Raman scattered light generated by the interaction between the laser beam and the sample S is measured. Since the Raman scattered light is generated every time the laser light is reflected by the sample surface 11, the Raman scattered light is generated a plurality of times. Therefore, the Raman scattered light detected by the Raman scattered light detection device is increased as compared with the method in which the laser beam is reflected by the sample surface 11 only once. The laser light can be easily reflected more than twice on the sample surface 11, and the Raman scattered light increases compared to the conventional technique in which the excitation light is incident twice on the sample. In the present embodiment, the laser light incident from the laser light source 2 and reflected by the sample surface 11 passes through different optical paths before and after being reflected by the mirror 31, so that it passes through different optical paths even after being reflected again by the sample surface 11. , It does not enter the laser light source 2. Therefore, no oscillation failure occurs in the laser light source 2, and the Raman scattered light detection device can operate stably.

  Further, in the present embodiment, the Raman scattered light is increased by making the laser light incident on the sample surface 11 a plurality of times, so that it is not necessary to increase the intensity of the laser light for the purpose of increasing the Raman scattered light. For this reason, it is difficult for the sample S to be damaged. In the present embodiment, since the reflection position when the laser beam is reflected a plurality of times on the sample surface 11 is different each time, the laser beam is not irradiated multiple times concentrated on one point on the sample S. For this reason, the damage of the sample S resulting from a laser beam being irradiated to a point on the sample S a plurality of times does not occur. Therefore, the Raman scattered light detection apparatus according to the present embodiment can increase the detectable Raman scattered light without causing laser oscillation failure and sample damage. By increasing the detectable Raman scattered light, the detection sensitivity of the Raman scattered light is improved, and the Raman spectroscopic analysis of the sample S can be performed with higher accuracy. In addition, since the generated Raman scattered light is weak, it is possible to perform Raman spectroscopic analysis on the sample S, which could not be detected by the conventional method, by increasing the Raman scattered light using the present invention. Become.

(Embodiment 2)
Since the Raman scattered light detection apparatus according to Embodiment 1 is configured to measure the Raman scattered light that has passed through the sample S, the sample S needs to be transparent. In the second embodiment, a Raman scattered light detection apparatus capable of measuring Raman scattered light even when the sample S is an opaque substance will be described.

  FIG. 2 is a schematic diagram showing the configuration of the Raman scattered light detection apparatus according to the second embodiment. In the present embodiment, the hemispherical prism 1 is formed with a truncated surface 16 parallel to the sample surface 11 including the spherical center of the spherical surface portion 12. The spherical surface portion 12 forms a part of a hemispherical surface. The three-dimensional shape of the hemispherical prism 1 is a shape obtained by rotating the cross-sectional view of the hemispherical prism 1 shown in FIG. 2 about an axis passing through the center of the sphere and perpendicular to the sample surface 11 and the truncated surface 16. As in the first embodiment, the spherical surface portion 12 is provided with a mirror coating portion 13 except for the entrance port 14 and the exit port 15. The condensing lens 41 is disposed at a position facing the truncated surface 16 of the hemispherical prism 1, and the detection unit 42 is disposed at a position where the Raman scattered light collected by the condensing lens 41 can be detected. . Other configurations of the Raman scattered light detection apparatus are the same as those of the first embodiment, and the corresponding parts are denoted by the same reference numerals and description thereof is omitted. Various optical components other than the condensing lens 41 may be provided between the hemispherical prism 1 and the detection unit 42.

  Also in this embodiment, the laser light is reflected by the sample surface 11 a plurality of times in the hemispherical prism 1, and Raman scattered light is generated from the sample S. It is easy for the laser light to be reflected more than twice on the sample surface 11. Since the generated Raman scattered light cannot pass through the opaque sample S, it passes through the hemispherical prism 1 and exits from the truncated surface 16. The emitted Raman scattered light is condensed by the condenser lens 41 and detected by the detection unit 42. Also in the present embodiment, the Raman scattered light detection apparatus can increase the detectable Raman scattered light and improve the detection sensitivity of the Raman scattered light without causing laser oscillation failure and damage to the sample. Note that the Raman scattered light detection device may have a configuration in which the detection units 42 are arranged on both the sample surface 11 side and the truncated surface 16 side.

(Embodiment 3)
FIG. 3 is a schematic diagram showing the configuration of the Raman scattered light detection apparatus according to the third embodiment. The mirror 31 is configured to be swingable about a predetermined axis. The mirror 31 is connected to a drive unit 32 that swings the mirror 31 with a motor. As the mirror 31 swings, the reflection angle at which the laser light is reflected fluctuates, and the optical path of the reflected laser light also fluctuates. The range in which the mirror 31 can swing is preferably within a range in which the angle at which the reflected laser light is reflected by the sample surface 11 can satisfy the condition of total reflection. Other configurations of the Raman scattered light detection apparatus are the same as those of the first embodiment, and the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  In the Raman scattered light detection apparatus according to the present embodiment, the laser light is incident on the hemispherical prism 1 while the mirror 31 is swung by the driving unit 32. As the mirror 31 swings, the optical path through which the laser light reflected by the mirror 31 enters the hemispherical prism 1 fluctuates, and the laser light is at a position different from the previously reflected position on the sample surface 11. Reflect again. The laser light reflected again by the sample surface 11 is reflected by the spherical surface portion 12 without being incident on the laser light source 2 as in the first embodiment. Thereafter, as in the first embodiment, the laser light is reflected by the sample surface 11 a plurality of times while changing the reflection position, Raman scattered light is generated by the sample S, and the Raman scattered light is detected by the detection unit 42. . It is easy for the laser light to be reflected more than twice on the sample surface 11. In particular, the mirror 31 is swung within a range where the total reflection condition is satisfied, so that the total reflection is performed a plurality of times. Also in the present embodiment, the Raman scattered light detection apparatus can increase the detectable Raman scattered light and improve the detection sensitivity of the Raman scattered light without causing laser oscillation failure and damage to the sample. As in the second embodiment, the Raman scattered light detection device may be configured to measure Raman scattered light even if the sample S is an opaque substance.

(Embodiment 4)
FIG. 4 is a schematic diagram showing the configuration of the Raman scattered light detection apparatus according to the fourth embodiment. In the present embodiment, the mirror coating portion 13 is not formed with the exit port 15 as in the first embodiment. Further, the spherical surface portion 12 of the hemispherical prism 1 has irregularities and has a shape deviated from the spherical surface of the true sphere. Other configurations of the Raman scattered light detection apparatus are the same as those of the first embodiment, and the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  The laser light incident on the hemispherical prism 1 by the laser light source 2 is reflected by the sample surface 11, then by the mirror coating portion 13 by the spherical surface portion 12, and again by the sample surface 11. Since the shape of the spherical surface portion 12 is shifted from the spherical surface of the true sphere, the forward and backward paths of the laser light before and after being reflected by the spherical surface portion 12 do not coincide with each other, and the laser light is the last time on the sample surface 11. Reflects at a position different from the reflected position. The laser light reflected again by the sample surface 11 is reflected by the spherical surface portion 12 without entering the laser light source 2 as in the first embodiment. Thereafter, as in the first embodiment, the laser light is reflected by the sample surface 11 a plurality of times while changing the reflection position, Raman scattered light is generated by the sample S, and the Raman scattered light is detected by the detection unit 42. . It is easy for the laser light to be reflected more than twice on the sample surface 11. Also in the present embodiment, the Raman scattered light detection apparatus can increase the detectable Raman scattered light and improve the detection sensitivity of the Raman scattered light without causing laser oscillation failure and damage to the sample. As in the second embodiment, the Raman scattered light detection device may be configured to measure Raman scattered light even if the sample S is an opaque substance.

(Embodiment 5)
In the fifth embodiment, a Raman scattered light detection device using a translucent member having a shape different from that of the hemispherical prism 1 is shown. FIG. 5 is a schematic diagram showing the configuration of the Raman scattered light detection apparatus according to the fifth embodiment. The Raman scattered light detection device includes a trapezoidal prism 5 as a translucent member. The trapezoidal prism 5 is made of a translucent material such as silica glass and is formed in a shape having a top surface, a side surface 52 and a bottom surface 53. The trapezoidal prism 5 has a top surface as a sample surface 51 on which the sample S is placed. The sample surface 51 and the bottom surface are parallel, and the side surface 52 is an inclined surface.

  The laser light source 2 is disposed at a position where the emitted laser light is incident on the trapezoidal prism 5 so as to be reflected by the plane mirror 34 and intersect the bottom surface 53. On the front surface of the laser light source 2, a mirror 33 having a hole 331 through which the emitted laser light passes is disposed. The mirror 33 reflects the laser light traveling toward the laser light source 2. The laser light incident on the trapezoidal prism 5 from the laser light source 2 is reflected by the side surface 52 inside the trapezoidal prism 5 and further reflected by the sample surface 51. In FIG. 5, the laser beam is indicated by a solid line with an arrow. It is desirable that the positions of the laser light source 1 and the plane mirror 34 and the inclination of the side surface 52 of the trapezoidal prism 5 satisfy the conditions for the total reflection of the laser light on the sample surface 51. The configuration of the Raman scattered light detection device may be a configuration in which various optical components other than the plane mirror 34 are provided between the laser light source 2 and the trapezoidal prism 5, and the laser light source 2 directly goes to the trapezoidal prism 5. A form in which laser light is incident may be used.

  The laser light incident on the trapezoidal prism 5 from the laser light source 2 and reflected by the sample surface 51 is reflected again by the side surface 52, intersects the bottom surface 53, and is emitted from the trapezoidal prism 5. The mirror 31 is disposed at a position where the laser light emitted from the trapezoidal prism 5 is incident. The laser light incident on the mirror 31 is reflected by the mirror 31, reenters the trapezoidal prism 5, is reflected by the side surface 52, and is reflected again by the sample surface 51. The mirror 31 is configured to be able to adjust the reflection angle of the laser beam with respect to the trapezoidal prism 5 by a user operation. The reflection angle of the mirror 31 is adjusted in advance so that the forward path and the return path of the laser beam do not match before and after reflection. Since the forward path and the return path of the laser light reflected by the mirror 31 do not coincide with each other, the laser light reflected by the mirror 31 and incident on the trapezoidal prism 5 is incident at different positions at an angle different from that at the time of emission. For this reason, the optical path of the laser beam in the trapezoidal prism 5 is different from that at the time of emission. Reflect at different positions.

  The laser light reflected again by the sample surface 51 is reflected by the side surface 52, intersects the bottom surface 53, exits from the trapezoidal prism 5, is reflected by the plane mirror 34, and enters the laser light source 2. The optical path of the laser light toward the laser light source 2 does not coincide with the optical path when emitted from the laser light source 2, and the laser light is reflected by the mirror 33 without passing through the hole 331 of the mirror 33. The laser beam reflected by the mirror 33 is reflected by the plane mirror 34 and enters the trapezoidal prism 5. The mirror 33 is configured to be able to adjust the reflection angle of the laser light by a user operation. The reflection angle of the mirror 33 is adjusted in advance so that the forward path and the return path of the laser light do not coincide before and after the reflection. Since the forward path and the return path of the laser light reflected by the mirror 33 do not coincide with each other, the laser light that is incident on the trapezoidal prism 5 after being reflected by the mirror 33 is incident at a position different from the previous incident time and outgoing time. Thereafter, the laser beam is reflected at a position different from the previously reflected position on the side surface 52, and is reflected at a position different from the previously reflected position on the sample surface 51. In this way, the laser beam is repeatedly reflected a plurality of times between the sample surface 51 and the mirror 31 and the mirror 33. In particular, when the condition that the laser beam is totally reflected by the sample surface 51 is satisfied, the laser beam is not emitted from the sample surface 51 and is reflected with high efficiency. The position of the sample surface 51 where the laser beam is reflected is different each time. Eventually, the laser light is attenuated within the trapezoidal prism 5 or emitted outside the trapezoidal prism 5. The mirror 31 and the mirror 33 correspond to the reflecting means in the present invention.

  The sample S is placed on the sample surface 51 of the trapezoidal prism 5. For example, the sample S is placed at the center of the sample surface 51. The sample S is assumed to be a transparent substance. When the laser beam is reflected by the sample surface 51 in the trapezoidal prism 5, part of the laser beam enters the sample S, and Raman scattered light is generated. For example, when the laser light is totally reflected by the sample surface 51, evanescent light is generated on the sample surface 51, and Raman scattered light is generated by the interaction between the evanescent light and the sample S. The generated Raman scattered light passes through the transparent sample S and is emitted out of the sample S. In FIG. 5, the Raman scattered light is indicated by a broken line with an arrow.

  A condensing lens 41 for condensing the Raman scattered light is disposed at a position facing the sample surface 51, and a detection unit 42 is disposed at a position for detecting the Raman scattered light condensed by the condensing lens 41. In addition to the condenser lens 41, various optical components such as various lenses and mirrors may be provided between the trapezoidal prism 5 and the detection unit 42.

  Also in this embodiment, the laser light is reflected by the sample surface 51 a plurality of times in the trapezoidal prism 5, and Raman scattered light is generated from the sample S. It is easy for the laser beam to be reflected more than twice on the sample surface 51. The generated Raman scattered light is collected by the condenser lens 41 and detected by the detection unit 42. Further, each time the laser light is reflected by the mirror 31 and the mirror 33, the optical path is changed so that the laser light does not enter the laser light source 2, and the reflection position when it is reflected a plurality of times by the sample surface 51 is different for each reflection. Therefore, also in the present embodiment, the Raman scattered light detection apparatus can increase the detectable Raman scattered light and improve the detection sensitivity of the Raman scattered light without causing laser oscillation failure and sample damage. it can.

  Note that the Raman scattered light detection device may have a configuration in which the mirror 31 is fixed in parallel with the bottom surface 53. Since the reflection surface of the mirror 31 is actually not a perfect plane due to the unevenness, the forward and backward paths of the laser light reflected by the mirror 31 do not coincide with the path. Therefore, even in this embodiment, it is possible to reflect the laser beam multiple times on the sample surface 51 while changing the reflection position, and increase the detectable Raman scattered light without causing laser oscillation failure and sample damage. Can be made.

  Further, as in the second embodiment, the Raman scattered light detection device arranges the condenser lens 41 at a position facing the bottom surface 53 of the trapezoidal prism 5 and detects the Raman scattered light collected by the condenser lens 41. A configuration in which the detection unit 42 is arranged at the position may be employed. In this form, the Raman scattered light generated from the sample S is transmitted through the trapezoidal prism 5, emitted from the bottom surface 53, and detected by the detection unit 42. In this form, Raman scattered light can be measured even if the sample S is an opaque substance.

  Further, the Raman scattered light detection device may have a configuration in which the mirror 31 can be swung as in the third embodiment, and the drive unit 32 that swings the mirror 31 may be provided. In this embodiment, the reflection angle of the laser beam reflected by the mirror 31 is changed by the swing of the mirror 31, and the laser beam is reflected by the sample surface 51 a plurality of times while changing the reflection position. In this embodiment, the position where the laser beam is reflected by the sample surface 51 can be uniformly distributed by the oscillation of the mirror 31, and the surface of the sample S can be uniformly excited by the laser beam. For this reason, it is also possible to perform Raman spectroscopic analysis of the entire surface of the sample S.

(Embodiment 6)
FIG. 6 is a schematic diagram showing the configuration of the Raman scattered light detection apparatus according to the sixth embodiment. On the front surface of the laser light source 2, a corner cube 36 having a hollow portion through which the emitted laser light passes is disposed. The corner cube 36 is a combination of two plane mirrors facing each other at an angle with each other. Laser light traveling toward the laser light source 2 is reflected by one reflecting surface and further reflected by the other reflecting surface. The angle at which the two plane mirrors are combined in the corner cube 36 is preferably adjusted so that the laser beam toward the laser light source 2 and the laser beam reflected twice by the corner cube 36 are parallel to each other. The laser light emitted from the laser light source 2 is reflected by the plane mirror 34 and enters the trapezoidal prism 5. The laser light incident on the trapezoidal prism 5 is reflected by the side surface 52 inside the trapezoidal prism 5 and further reflected by the sample surface 51. In FIG. 6, the laser beam is indicated by a solid line with an arrow.

  The laser beam reflected by the sample surface 51 is reflected again by the side surface 52, intersects the bottom surface 53, and is emitted from the trapezoidal prism 5. A corner cube (reflector) 35 is disposed at a position where the laser beam emitted from the trapezoidal prism 5 is incident. The laser light emitted from the trapezoidal prism 5 is reflected by one reflecting surface of the corner cube 35, further reflected by the other reflecting surface, and intersects the bottom surface 53 and enters the trapezoidal prism 5. The angle at which the two plane mirrors are combined in the corner cube 35 is adjusted so that the laser light emitted from the trapezoidal prism 5 and the laser light reflected twice by the corner cube 35 and incident on the trapezoidal prism 5 are parallel. It is desirable. Further, the corner cube 35 is configured to be able to adjust the relative position with respect to the trapezoidal prism 5 by a user's operation. Since the optical path of the laser light is moved by being reflected twice by the corner cube 35, the laser light incident on the trapezoidal prism 5 after being reflected by the corner cube 35 enters a position different from that at the time of emission. For this reason, the laser beam is reflected at a position different from the previously reflected position of the side surface 52 and further reflected at a position different from the previously reflected position of the sample surface 51.

  The laser light reflected again by the sample surface 51 is reflected by the side surface 52, intersects the bottom surface 53, exits from the trapezoidal prism 5, is reflected by the plane mirror 34, and travels toward the laser light source 2. The optical path of the laser light toward the laser light source 2 does not match the optical path when emitted from the laser light source 2. The laser light is reflected twice by the corner cube 36, reflected by the plane mirror 34, and incident on the trapezoidal prism 5. Since the optical path of the laser beam moves by being reflected twice by the corner cube 36, the laser beam incident on the trapezoidal prism 5 after being reflected by the corner cube 36 is incident at a position different from the time of the previous incidence and emission. To do. Thereafter, the laser beam is reflected at a position different from the previously reflected position on the side surface 52, and is reflected at a position different from the previously reflected position on the sample surface 51. In this way, the laser beam is repeatedly reflected a plurality of times between the sample surface 51 and the corner cube 35 and the corner cube 36. In particular, when the condition that the laser beam is totally reflected by the sample surface 51 is satisfied, the laser beam is not emitted from the sample surface 51 and is reflected with high efficiency. The position where the laser beam is reflected by the sample surface 51 is different every time. Eventually, the laser light is attenuated within the trapezoidal prism 5 or emitted outside the trapezoidal prism 5. The corner cube 35 and the corner cube 36 correspond to the reflecting means in the present invention. Other configurations of the Raman scattered light detection apparatus are the same as those of the fifth embodiment, and the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  Also in this embodiment, the laser light is reflected by the sample surface 51 a plurality of times in the trapezoidal prism 5, and Raman scattered light is generated from the sample S. It is easy for the laser beam to be reflected more than twice on the sample surface 51. The generated Raman scattered light is detected by the detector 42. Further, each time the laser light is reflected by the corner cube 35 and the corner cube 36, the optical path is changed so that it does not enter the laser light source 2, and the reflection position when it is reflected a plurality of times by the sample surface 51 is different for each reflection. . Therefore, also in the present embodiment, the Raman scattered light detection apparatus can increase the detectable Raman scattered light and improve the detection sensitivity of the Raman scattered light without causing laser oscillation failure and sample damage. it can. In the present embodiment, the corner cube 35 and the corner cube 36 can change the optical path without changing the angle of the laser beam. Further, by adjusting the position of the corner cube 35, the distance that the forward path and the return path of the laser light are separated before and after being reflected by the corner cube 35 can be adjusted. By adjusting this distance, the number of times the laser beam is reflected by the sample surface 51 is adjusted, and the intensity of the Raman scattered light is adjusted.

  As in the second embodiment, the Raman scattered light detection device arranges the condenser lens 41 at a position facing the bottom surface 53 of the trapezoidal prism 5 and detects the Raman scattered light collected by the condenser lens 41. A configuration in which the detection unit 42 is arranged at the position may be employed. In this form, Raman scattered light can be measured even if the sample S is an opaque substance.

(Embodiment 7)
FIG. 7 is a schematic diagram showing the configuration of the Raman scattered light detection apparatus according to the seventh embodiment. The Raman scattered light detection apparatus according to the present embodiment includes a parabolic mirror (reflector) 37 whose reflecting surface forms a parabolic surface instead of the corner cube 35 in the sixth embodiment. Further, the Raman scattered light detection device includes a parabolic mirror 38 in which a hole through which the laser light emitted from the laser light source 2 passes is provided instead of the corner cube 36 in the sixth embodiment. The parabolic mirror 37 and the parabolic mirror 38 correspond to the reflecting means in the present invention. Other configurations of the Raman scattered light detection apparatus are the same as those of the sixth embodiment, and the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  Also in the present embodiment, the laser light is repeatedly reflected a plurality of times between the sample surface 51, the parabolic mirror 37, and the parabolic mirror 38, and Raman scattered light is generated from the sample S. It is easy for the laser beam to be reflected more than twice on the sample surface 51. Each time the laser beam is reflected by the parabolic mirror 37 and the parabolic mirror 38, the optical path is changed so that the laser beam does not enter the laser light source 2, and the reflection position when reflected by the sample surface 51 a plurality of times is reflected. Different each time. Therefore, also in the present embodiment, the Raman scattered light detection apparatus can increase the detectable Raman scattered light and improve the detection sensitivity of the Raman scattered light without causing laser oscillation failure and sample damage. it can. Further, by adjusting the position of the parabolic mirror 37, it is possible to adjust the distance that the forward path and the backward path of the laser beam before and after being reflected by the parabolic mirror 37 are separated. By adjusting this distance, the number of times the laser beam is reflected by the sample surface 51 is adjusted, and the intensity of the Raman scattered light is adjusted.

  As in the second embodiment, the Raman scattered light detection device arranges the condenser lens 41 at a position facing the bottom surface 53 of the trapezoidal prism 5 and detects the Raman scattered light collected by the condenser lens 41. A configuration in which the detection unit 42 is arranged at the position may be employed. In this form, Raman scattered light can be measured even if the sample S is an opaque substance.

(Embodiment 8)
FIG. 8 is a schematic diagram showing the configuration of the Raman scattered light detection apparatus according to the eighth embodiment. On the front surface of the laser light source 2, a flat plate-like double-sided mirror 61 whose both surfaces are mirror surfaces is disposed. The double-sided mirror 61 is arranged at a position where the laser beam from the laser light source 2 is reflected and incident on the trapezoidal prism 5 and reflected by one side surface 52 among the side surfaces 52 existing on both sides of the sample surface 51. Yes. That is, the laser light from the laser light source 2 is reflected by the double-sided mirror 61, enters the trapezoidal prism 5, is reflected by one side surface 52 inside the trapezoidal prism 5, and is further reflected by the sample surface 51. In FIG. 8, the laser beam is indicated by a solid line with an arrow. It is desirable that the position of the laser light source 1, the position and inclination of the double-sided mirror 61, and the inclination of the side surface 52 with respect to the sample surface 51 satisfy the conditions for total reflection of the laser light on the sample surface 51. Note that the configuration of the Raman scattered light detection device may include a configuration in which various optical components other than the plane mirror 34 are provided between the laser light source 2 and the double-sided mirror 61.

  The laser beam reflected by the sample surface 51 is then reflected by the other side surface 52 and emitted after intersecting the bottom surface 53. A mirror 63 is disposed at a position where the laser light emitted from the trapezoidal prism 5 is incident. A plane mirror 62 larger than the double-sided mirror 61 is disposed in parallel to the double-sided mirror 61 at a position farther from the trapezoidal prism 5 than the double-sided mirror 61. The mirror 63 and the plane mirror 62 are opposed to each other at an angle. The position and inclination of the mirror 63 are determined so that the laser light emitted from the trapezoidal prism 5 is reflected and enters the plane mirror 62. The position and tilt of the mirror 63 are determined so that the reflected laser light does not enter the double-sided mirror 61. The position and inclination of the mirror 63 are preferably determined so that the optical path of the laser light reflected and incident on the plane mirror 62 is parallel to the optical path of the laser light incident on the double-sided mirror 61 from the laser light source 2. . The mirror 63 is arranged at a position away from the optical path of the laser light incident on the double-sided mirror 61 from the laser light source 2.

  The laser beam reflected by the mirror 63 and incident on the plane mirror 62 is reflected by the double-sided mirror 61 and enters the trapezoidal prism 5 again, or between the plane mirror 62 and the reflecting surface of the double-sided mirror 61 on the side facing the plane mirror 62. The reflection is repeated at least once, and finally reflected by the plane mirror 62 and enters the trapezoidal prism 5. The laser light incident on the trapezoidal prism 5 is reflected by one side surface 52 and reflected by the sample surface 51. The optical path of the laser beam reflected by the plane mirror 62 and incident on the trapezoidal prism 5 does not match the optical path of the laser beam reflected by the double-sided mirror 61 and incident on the trapezoidal prism 5. Therefore, the laser light reflected by the plane mirror 62 and incident on the trapezoidal prism 5 is reflected on the side surface 52 at a position different from the position where the laser light reflected by the double-sided mirror 61 and incident on the trapezoidal prism 5 is reflected. Further, the laser beam is reflected again at a position different from the position where the sample surface 51 was previously reflected. The laser beam reflected again by the sample surface 51 is reflected by the other side surface 52, intersects the bottom surface 53, exits from the trapezoidal prism 5, and is reflected by the mirror 63. The tilt and position of the double-sided mirror 61 and the plane mirror 62 are determined by the optical path of the laser beam reflected by the double-sided mirror 61 and incident on the trapezoidal prism 5 and the optical path of the laser beam reflected by the plane mirror 62 and incident on the trapezoidal prism 5. It is desirable that they are determined to be parallel. Further, the position of the laser light source 1, the position and inclination of the double-sided mirror 61, the plane mirror 62 and the mirror 63, and the inclination of the side surface 52 of the trapezoidal prism 5 are perpendicular to the bottom surface 53. It is desirable that it is determined to do so.

  As described above, the laser beam is repeatedly reflected a plurality of times between the sample surface 51, the side surface 52, the mirror 63, the double-sided mirror 61, and the plane mirror 62. The position where the laser beam is reflected by the sample surface 51 is different every time. In particular, when the condition that the laser beam is totally reflected by the sample surface 51 is satisfied, the laser beam is not emitted from the sample surface 51 and is reflected with high efficiency. Further, when the laser beam incident on and emitted from the trapezoidal prism 5 is orthogonal to the bottom surface 53, there is a condition that the amount of laser light is less attenuated when passing through the bottom surface 53 and the laser beam is totally reflected by the sample surface 51. Kept. The mirror 63, the double-sided mirror 61, and the plane mirror 62 correspond to the reflecting means in the present invention.

  The plane mirror 62 is configured to be able to adjust the distance from the double-sided mirror 61 by adjusting the position by the user's operation. The closer the plane mirror 62 is to the double-sided mirror 61, the narrower the region where the laser light reflected by the plane mirror 62 and incident on the trapezoidal prism 5 is reflected by the side surface 52, and the region where the laser beam is reflected by the sample surface 51 is also narrowed. Conversely, the farther the plane mirror 62 is from the double-sided mirror 61, the wider the area where the laser light reflected by the plane mirror 62 and incident on the trapezoidal prism 5 is reflected by the side surface 52, and the area where the laser light is reflected by the sample surface 51 is wider. Become. Therefore, by adjusting the position of the plane mirror 62, it is possible to adjust the size of the region in the sample S that is excited by laser light and generates Raman scattered light. By adjusting the size of the region where the Raman scattered light is generated, the position and size of the portion of the sample S where the Raman spectroscopic analysis should be performed can be adjusted. Other configurations of the Raman scattered light detection apparatus are the same as those of the fifth embodiment, and the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  Also in the present embodiment, the laser light is reflected by the sample surface 51 a plurality of times in the trapezoidal prism 5, and Raman scattered light is generated from the sample S every time it is reflected. It is easy for the laser beam to be reflected more than twice on the sample surface 51. The generated Raman scattered light is detected by the detector 42. Further, the optical path of the laser beam is different between when it is first reflected by the double-sided mirror 61 and incident on the trapezoidal prism 5 and when it is reflected by the plane mirror 62 and incident on the trapezoidal prism 5. The light path is different each time. For this reason, the reflection position when the laser beam is reflected a plurality of times on the sample surface 51 is different for each reflection, and the laser beam is not irradiated a plurality of times concentrated on one point on the sample S. Therefore, also in this embodiment, the Raman scattered light detection apparatus can increase the detectable Raman scattered light without causing damage to the sample S, and can improve the detection sensitivity of the Raman scattered light. In particular, when the condition that the laser beam is totally reflected by the sample surface 51 is satisfied, and the laser beam incident on and emitted from the trapezoidal prism 5 is orthogonal to the bottom surface 53, the efficiency of exciting the sample S with the laser beam is high. The Raman scattered light is further increased.

  In the present embodiment, the laser light incident on the trapezoidal prism 5 is reflected on one side surface 52, and the laser light emitted from the trapezoidal prism 5 is reflected on the other side surface 52 immediately before. Since the optical path of the laser light incident on the trapezoidal prism 5 and the optical path of the laser light emitted from the trapezoidal prism 5 are completely separated, the laser light does not enter the laser light source 2 and a laser oscillation failure occurs. There is nothing to do.

  In the Raman scattered light detection device, the condenser lens 41 is arranged at a position facing the bottom surface 53 of the trapezoidal prism 5, and the detection unit 42 is arranged at a position where the Raman scattered light collected by the condenser lens 41 is detected. The form may be sufficient. In this form, Raman scattered light can be measured even if the sample S is an opaque substance. In FIG. 8, the mirror 63 is disposed at a position farther from the trapezoidal prism 5 than the optical path of the laser light incident on the double-sided mirror 61 from the laser light source 2. The mirror 63 may be arranged at a position close to the position.

  Moreover, in the above Embodiments 1-8, although the sample surface used as the mounting surface of the sample S was shown, the Raman scattered light detection apparatus of this invention arrange | positions a sample surface above a sample, etc. The sample surface may be in a direction other than upward. In the above first to eighth embodiments, the laser beam is used as the light beam. However, the present invention uses a light beam other than the laser beam, such as a non-coherent beam focused using a collimator. It may be in the form.

1 Hemispherical prism (translucent member)
11 Sample surface 12 Spherical surface part 13 Mirror coating part 2 Laser light source (incident part)
31, 33 Mirror (reflector)
32 Drive unit 35, 36 Corner cube (reflector)
37, 38 Parabolic mirror (reflector)
42 Detector 5 Trapezoidal prism 51 Sample surface 52 Side surface 61 Double-sided mirror 62 Plane mirror 63 Mirror

Claims (6)

A light-transmitting member having a flat sample surface with which an arbitrary sample is brought into contact with, an incident portion for entering a light beam into the light-transmitting member so as to be reflected by the sample surface, and the light beam generated in the sample And a means for detecting Raman scattered light to detect Raman scattered light,
Reflecting means for reflecting the light beam after being reflected by the sample surface again, entering the sample surface, and reflecting the light beam at a position different from the position previously reflected on the sample surface on the sample surface. A feature of the Raman scattered light detection device. The reflecting means is
The Raman scattered light detection apparatus according to claim 1, further comprising means for reflecting a light beam directed toward the incident portion. The reflecting means is
3. The reflector according to claim 1, further comprising a reflector that reflects the light beam reflected from the sample surface and emitted from the translucent member so as to be incident on the translucent member while changing an optical path. Raman scattering detector. The Raman scattering detection device according to claim 3, wherein the reflector is configured to be capable of adjusting a reflection angle of light. The reflector is configured to be swingable so that the reflection angle of light continuously changes,
The Raman scattering detection device according to claim 3, further comprising a drive unit that swings the reflector. The translucent member is a hemispherical prism having a plane portion as the sample surface,
The reflecting means is
The mirror coating part which mirror-coated the spherical part of the hemispherical prism except a part so that light may reflect in the inside of the hemispherical prism is characterized by the above-mentioned. The Raman scattering detector described in 1.

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