JPH02243929A - Fourier transform infrared spectrophotometer - Google Patents

Abstract

PURPOSE:To improve S/N with a simple condensing optical system by selecting the focal distance of 1st and 2nd paraboloidal mirrors according to the optical path length from the 1st parabolic mirror via a sample part to the 2nd parabolic mirror. CONSTITUTION:The sample S is set on a sample base 28 perpendicularly to a base plate in the case of analyzing the sample S by a micropoint transmission measurement method. The parabolic mirrors 26, 27 necessary for a desired beam diameter are then selected. A detecting part 23 is registered by moving stages 31, 33, 35 in directions x, y, z in such a manner that the optical axis of the transmitted light reflected in the direction x by the mirror 27 and the incident optical axis of the detecting part 23 align to each other. The IR light emitted from a light source 24 is thereafter introduced through a collimator 25 to an interferometer. The luminous flux emitted in the direction x from the interferometer part 21 is condensed via the parabolic mirror 26 to the sample S. The luminous flux transmitted and diffused through the sample S is condensed via the mirror 27 and a condenser mirror 29 to a detector 30.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a Fourier transform infrared spectrophotometer, and in particular, to a Fourier transform infrared spectrophotometer with a good signal-to-noise ratio (S/N) using a simple focusing optical system. Regarding infrared spectrophotometer.

[Prior Art] Conventionally, a Fourier transform infrared spectrophotometer having a configuration as shown in FIG. 3 is known. In FIG. 3, the Fourier transform infrared spectrophotometer 1 is integrally constructed from a light source section 2, an interferometer section 3, a sample chamber 4, and a detection section 5. The infrared light emitted from the light source 6 in the light source section 2 is made into parallel light by a collimator 7,
It is introduced into the interferometer section 3. The light beam emitted from the interferometer section 3 is focused on a sample 8 placed in a sample chamber 4. The light beam transmitted through the sample 8 and diffused is introduced into the detection section 5, and is focused on the detector 11 via the condensing mirrors 9 and 10.

[Problems to be Solved by the Invention] In the apparatus configured as described above, various condensing optical systems are incorporated in the sample chamber 4 depending on the sample measurement method. For example, the sample chamber 4 includes an optical system using an ATR crystal 12 and reflectors a to d for total internal reflection absorption measurement as shown in FIG. 4, and a minute point measurement as shown in FIG. In order to do this, a complicated beam condenser optical system using a reflecting mirror e-1, etc. is installed together with the sample. Now, in these optical systems, it is necessary to match the incident optical axis of the optical system with the output optical axis of the interferometer section 3, and the output optical axis of the optical system with the incident optical axis of the detection section 5, so there are many Reflecting mirrors are used to guide light rays to each optical axis. However, when a large number of reflecting mirrors are used in this manner, the absorption and attenuation of the analysis light by the reflecting mirrors increases, resulting in a poor signal-to-noise ratio (S/N) and a decrease in analysis accuracy. .

In addition, even though the volume of the sample chamber 4 is limited, many reflecting mirrors are installed in the sample chamber to guide the light beam to each optical axis, so the size of the sample that can be accommodated is limited. The problem is that it is limited by the condensing optical system used.

The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a Fourier transform infrared light ejection system that uses a simple condensing optical system and has a good signal-to-noise ratio (S/N).

[Means for Solving the Problems] The present invention provides a base, an interferometer section disposed on the base,
A Fourier transform infrared spectrophotometer comprising a sample section into which a light beam emitted from the interferometer section is introduced, and a detection section disposed on the substrate for detecting the light beam emitted from the sample section. In the plane parallel to the X direction and the
Considering the X direction perpendicular to the direction, an X moving mechanism is provided for moving the detection section in the X direction relative to the interferometer section, and X
A y-moving mechanism is provided for moving the sample section in the X direction, and a mechanism is provided for moving the sample section in the X direction and the X direction. A first parabolic mirror is arranged to reflect the light in the X direction and guide it to the sample section, and a second parabolic mirror is arranged to reflect the light from the sample section in the X direction and guide it to the detection section. are arranged such that parallel light incident on the first parabolic mirror exits as parallel light from the second parabolic mirror via the sample section. A mechanism for making the position of the second parabolic mirror variable is provided, and the focal length of the first and second parabolic mirrors is different from the first parabolic mirror through the sample part. The second parabolic mirror is selected according to the optical path length leading to the second parabolic mirror.

[Function] In the present invention, since the detection unit is movable relative to the interferometer unit, it is not necessary to provide a reflecting mirror in the sample chamber to align the incident optical axis and the output optical axis as in the conventional case. Thus, a Fourier transform infrared spectrophotometer is realized in which the condensing optical system can be simplified.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. 1st
The figure is a configuration diagram of an apparatus for explaining an embodiment of the present invention, and FIG. 2 is a diagram for explaining the operation.

In FIGS. 1 and 2, 20 is a base, 21 is an interferometer section, 22 is a sample chamber, 23 is a detection section, 24 is a light source, 25 is a collimator, 26.27 is a parabolic mirror, 28 is a sample stage, 29
30 is a detector, 31 is a moving stage in the X direction,
32 is a guide rail for moving in the X direction, 33 is a stage for moving in the X direction, 34 is a guide rail for moving in the X direction, 35 is a detection part support stage, 36 is a guide rail for moving in two directions, 3
7°38.39 is a scale, 40, 41.42 is a stage stopper, and 43, 44, 45, 46 is a purge cylinder.

In a plane parallel to the base 20, an X direction and an X direction perpendicular to the X direction are defined as shown in FIG. 1, and two directions are defined as directions perpendicular to the plane.

The X-direction moving stage 31 is guided by guide rails 32 and is attached to be movable in the X-direction. Said X
The directional movement stage 33 is guided by a guide rail 34 provided on the stage 31 and is attached to be movable in the X direction. The detection section support stage 35 is guided by a guide rail 36 provided on the stage 33 and is mounted so as to be movable in two directions, and the detection section 23 is disposed on the stage 35.

The parabolic mirrors 26 and 27 are provided to be rotatable around the axes A and B in the X direction, and movable in the X direction and the X direction and two directions.

The purge cylinders 43 to 46 are connected to the interferometer section 21 and the sample chamber 22.
It seals the optical path between the sample chamber 22 and the detection section 23, and is provided so as to be expandable and retractable as the parabolic mirror moves.

In the device configured as described above, minute point transmission i1P+
When analyzing a sample S using a conventional method, the sample S is set perpendicularly to the base 20 on a sample stage 28 in a sample chamber 22, as shown in FIG. Next, the parabolic mirrors 26 and 27 necessary to obtain the desired beam diameter are selected, and the parabolic mirror 26 directs the light traveling along the X direction from the interferometer section 21 in the X direction. The paraboloid m27 is placed at a position to reflect the sample transmitted light from the sample chamber 22 in the X direction. The detection unit 23 is arranged so that the optical axis of the transmitted light reflected in the X direction by the parabolic mirror 27 and the incident optical axis of the detection unit 23 match.
X-direction moving stage 31, X-direction moving stage 33.
Positioning is performed using a two-direction moving stage 35.

After such alignment, the infrared light emitted from the light source 24 in the interferometer section 21 is made into parallel light by the collimator 25 and introduced into the interferometer. The light beam emitted as parallel light from the interferometer section 21 in the X direction is reflected by the parabolic mirror 26 in a direction perpendicular to the X direction, and is focused on the sample S placed in the sample chamber 22. . The light flux that has passed through the sample S and diffused is reflected in the X direction by the parabolic mirror 27 and introduced into the detection section 23, and then passed through the condenser mirror 29 to the detector 30.
The light is focused on.

On the other hand, when analyzing the sample S using the minute point transmission measurement method, and when the sample S needs to be set horizontally with respect to the base 20, the detection unit must be moved as shown in Fig. 2. That's fine. That is, from the state of the embodiment shown in FIG.
First, the paraboloid m26 is rotated about its axis and set so that the incident light is reflected downward (in two directions). Next, the sample chamber 22 is arranged below the parabolic mirror 26. Then, the detection unit 23 is moved downward (in two directions) by the detection unit support stage 35, and the X-direction moving stage 3
3, it is horizontally moved in the X direction and placed in the lower part of the sample chamber 22. At this position, the parabolic mirror 27 is rotated along with the support B, and set so that the transmitted light from the sample chamber 22 is reflected in the X direction. Then, the detection section 23 is aligned by the X-direction moving stage 31, the X-direction moving stage 33, and the detection section support stage 35 so that the optical axis of the reflected transmitted light and the incident optical axis of the detection section 23 match. Ru. As a result, the infrared light emitted from the interferometer section 21 passes through the horizontally set sample and is introduced into the detection section 23.

Note that the above-described embodiment is only one embodiment of the present invention, and the present invention can be implemented with various modifications. For example, in the above-mentioned embodiment, the case where the present invention is applied to transmission A11j constant has been described, but it can also be applied to various measurements such as reflection A11j constant by moving the detection section appropriately.

Further, in the embodiments described above, the detection section is provided movably, but the interferometer section may be provided movably, or both the detection section and the interferometer section may be provided movably.

Furthermore, in the embodiment described above, the detection section is X.

Although it is designed to be movable in three directions (y and z), it can be moved in two directions (x+Y).
It may be possible to move only in the direction.

[Effects of the Invention] As is clear from the above description, according to the present invention, an X moving mechanism for moving the detection unit in the X direction relative to the interferometer unit and a An X moving mechanism and a mechanism for moving the sample section in the X direction and the X direction are provided, and the light traveling along the X direction from the interferometer section is reflected in a direction perpendicular to the a first parabolic mirror for guiding the light from the sample section to the detection section; and a second parabolic mirror for reflecting the light from the sample section in the X direction and guiding it to the detection section; The first parabolic mirror is configured such that the parallel light incident on the plane mirror is output as parallel light from the second parabolic mirror via the sample section. A mechanism for making the position of the second parabolic mirror variable is provided, and the second parabolic mirror is arranged at a variable position. By selecting the focal length of the second parabolic mirror according to the optical path length from the first parabolic mirror to the second parabolic mirror via the sample section, the light is reflected into the sample chamber as in the conventional method. There is no need to install a mirror to align the incident optical axis and the output optical axis, and the S
/N can be realized. Further, since there is no need to provide a large number of reflecting mirrors in the sample chamber as in the conventional case, a large sample can also be arbitrarily set in the sample chamber. Furthermore, the shape of the sample and A11
Even if an arbitrary sample chamber is provided depending on the method of determination, a desired optical system can be easily obtained by simply moving the detection section and the parabolic mirror.

[Brief explanation of drawings]

FIG. 1 is an apparatus configuration diagram for explaining an embodiment of the present invention, FIG. 2 is a diagram for explaining the operation, and FIGS. 3 to 5 are diagrams for explaining a conventional example. 20: Base 21: Interferometer section 22: Sample chamber 23: Detection section 24: Light? fA
25: Collimator 26. 27: Parabolic mirror 28: Sample stage 29: Condensing mirror 30: Detector 31: 32: 33 = 34 235 236: X direction movement stage Guide rail for X direction movement X direction movement stage Guide rail for X-direction movement Detector support stage Guide rail for 2-direction movement

Claims (2)

[Claims] (1) A base, an interferometer section placed on the base, a sample section into which the light beam emitted from the interferometer section is introduced, and a sample section placed on the base for detecting the light beam emitted from the sample section. In a Fourier transform infrared spectrophotometer equipped with a detection section, consider an x direction and a y direction perpendicular to the x direction in a plane parallel to the base, and set the detection section relative to the interferometer section. an x-movement mechanism for moving the sample section in the x-direction; a y-movement mechanism for moving the detection section in the y-direction relative to the interferometer section;
a first paraboloid provided with a mechanism for moving in the direction and the y direction, and for reflecting the light traveling along the x direction from the interferometer section in a direction perpendicular to the x direction and guiding it to the sample section. A plane mirror is arranged, and a second parabolic mirror is arranged to reflect the light from the sample section in the x direction and guide it to the detection section, and the parallel light incident on the first parabolic mirror is is provided with a mechanism for making the positions of the first and second parabolic mirrors variable such that parallel light is emitted from the second parabolic mirror via the sample portion; The focal length of the first and second parabolic mirrors is selected according to the optical path length from the first parabolic mirror to the second parabolic mirror via the sample section. Fourier transform infrared spectrophotometer. (2) A base, an interferometer section placed on the base, a sample section into which the light beam emitted from the interferometer section is introduced, and a sample section placed on the base for detecting the light beam emitted from the sample section. In a Fourier transform infrared spectrophotometer equipped with a detection section, considering an x direction, a y direction perpendicular to the x direction, and a z direction perpendicular to the plane in a plane parallel to the base, the interferometer section a y-moving mechanism for moving the detection unit in the y-direction relative to the interferometer unit, and a z-moving mechanism for moving the detection unit in the z-direction relative to the interferometer unit; A mechanism for moving the sample section in the y direction and the z direction is provided, and the light traveling along the x direction from the interferometer section is reflected in a direction perpendicular to the x direction and guided to the sample section. A first parabolic mirror is arranged, a second parabolic mirror is arranged to reflect light from the sample section in the x direction and guide it to the detection section, and the first parabolic mirror The positions and orientations of the first and second parabolic mirrors are variable so that the parallel light incident on the sample part passes through the sample section and exits from the second parabolic mirror as parallel light. and the focal length of the first and second parabolic mirrors is selected according to the optical path length from the first parabolic mirror to the second parabolic mirror via the sample section. A Fourier transform infrared spectrophotometer characterized by: