JPH04115141A - Microspectrophotometer - Google Patents

Abstract

PURPOSE:To enable measurement of an infrared emission spectrum emitted from a microscopic part of a sample heated being magnified with a microscope by heating the sample on a sample base with a heater to take infrared rays generated into the microscope. CONSTITUTION:A sample 2 placed on a sample base 1 with a heater is heated with the heater and emits infrared rays 3. The infrared rays 3 are taken into a microscope with a Cassegrainian reflection objective lens 4. Two edge mirrors 5 and 9 are so set as to be shielded only by a portion equivalent to a half of optical paths while letting knife edges of the both contact each other on an optical axis. The infrared rays 3 are impinged into an interferometer 7 of a Fourier transform infrared spectroscope with the first edge mirror 5 and a concave mirror 6. Those interfered with the interferometer 7 alone of the infrared rays 3 are reflected to become infrared rays 8. The infrared rays 8 are reflected with the edge mirror 9 and condensed on a detector 11 with a Cassegrainian reflection objective lens 10. Thus, an interferogram of the infrared rays emitted from the sample 2 is measured with the detector 11.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an apparatus for measuring infrared absorption spectra of extremely small parts, and in particular, it is capable of simultaneously observing the measurement site and detecting the infrared absorption spectrum of extremely small parts. The present invention relates to a microscope device for measuring infrared absorption spectra suitable for accurately measuring infrared emission spectra.

[Conventional technology]

In general, infrared absorption spectrum measuring devices are already known and consist of an infrared light source, a monochromator or interferometer for obtaining the infrared intensity of each wavelength component, an interferometer, an infrared detector, a sample chamber, etc. . Since the Fourier infrared spectrophotometer using an interferometer is highly sensitive for measuring infrared absorption spectra in extremely small areas, Robert Gee Messerschmitt has traditionally used John of Infrared
Microscope [The Design.

Sample Handling and Aplic
ation of InfraredMicrosco
pes, ASTM STD 949. American
5ocjetyfor Testing and M
aterials, Ph1ladelphia (198
7), ), pp. 27-31, and InfraRed Microscopy (Practic) published by Marshall Detzker Publishing.
al 5pectroscopy 5eries Vo
lume 6 Infrared Microspec
troscopyEdited by Robert
G.

Messerschmidt MARCEL DEKK
ERINC, (1988)), pp. 85-87.

These documents contain schematic drawings of microscopes as shown in FIGS. 7 and 8. 31 in Figures 7 and 8 is a sample stage;
4 is a Cassegrain reflective objective lens, 33 is a condenser,
32 and 32' in Figure 7 are apertures to limit the measurement field of view, 1o in Figure 8 is a Cassegrain reflective objective lens for condensing light, and 11 in Figures 7 and 8 is an infrared detector. It is. The infrared rays from the interferometer of the Fourier transform infrared spectrometer are shown at 8 in FIGS. 7 and 8.

Measurement of the infrared absorption spectrum of a sample is generally performed in either transmission measurement or reflection measurement mode.

In the transmission measurement mode, as shown in Figures 7 and 8, the infrared IX8 from the interferometer 7 of the Fourier transform infrared spectrometer is focused onto the sample by the condenser 33, and the infrared rays that have passed through the sample are reflected by Cassegrain. The light passes through the objective lens 4 and reaches the detector 11 . In the case of reflection measurement mode, in FIG. The infrared rays are reflected by the flat edge mirror 5 and the Cassegrain type reflective objective lens 4 and focused onto the sample, and the infrared rays after being reflected by the sample reach the detector 11 via the Cassegrain type reflective objective lens 4 . This makes it possible to measure the infrared absorption spectrum of the sample.

However, the devices shown in Figures 7 and 8 both use the optical system of a commonly used optical microscope, and the infrared rays that are transmitted through the sample or reflected by the sample are detected as they are through the lens barrel of the microscope. The light enters the vessel 11. For this purpose, the infrared rays generated by heating the sample are sent to the interferometer of the Fourier transform infrared spectrophotometer, and the infrared rays modulated here are returned to the detector 11 in the microscope section to emit infrared light. It is not designed to measure spectra.

On the other hand, in general, to measure infrared emission spectra with a Fourier transform spectrophotometer, instead of heating a globe or tungsten wire to generate infrared rays, the sample is heated with a heater to generate infrared rays, and this is interfered with. After modulating it with a meter, it is detected with a detector and the infrared emission spectrum is measured. However, this method is not suitable for measuring the infrared emission spectrum of a minute portion of a sample.

[Problem to be solved by the invention]

The purpose of the present invention is to place a sample on the sample stage of a microscope,
The purpose of this method is to heat a sample with a heater and measure the infrared emission spectrum of a minute portion under a microscope.

[Means to solve the problem]

To measure the infrared emission spectrum of an extremely small portion of a sample heated by a heater placed on the sample stage 1 of the microscope, infrared light emitted by the sample is focused by a reflective objective lens attached to the microscope. Since the focused infrared light is not modulated, it is not possible to obtain an infrared emission spectrum even if the detector measures it as it is.

Therefore, it is necessary to return the modulated infrared rays to the interferometer of the Fourier transform infrared spectrometer and return them to the detector of the microscope.

In the infrared microscope, an edge mirror 5 as shown in Figures 8 and 9 is used to irradiate the sample with infrared rays from the interferometer of the Fourier transform infrared spectrometer and to guide the infrared rays from the sample to the detector. A beam splitter consisting of By adding a mirror to this mirror that can reflect the infrared rays from the interferometer of the Fourier transform infrared spectrometer not only to the sample side but also to the detector side, the infrared rays generated from the sample can be reflected.
The infrared rays are modulated by the interferometer and returned to the microscope, where they enter the detector. This allows the detector to measure the infrared emission spectrum of the extremely small portion of the sample placed on the heater placed on the microscope sample stage.

[Effect]

Hereinafter, the operation of the present invention will be explained with reference to FIG.

A sample 2 placed on a sample stage 1 with a heater is heated by a heater and infrared, s! Generates 3. This infrared ray 3 is taken into the microscope by a Cassegrain type reflective objective lens 4. The two edge mirrors 5 and 9 are installed so that they block only half of the optical path and their knife edges are in contact with each other on the optical axis. The infrared rays 3 are transmitted through the first edge mirror 5 and the concave mirror 6.
The light is incident on the interferometer 7 of the Fourier transform infrared spectrometer. Only the infrared rays 3 that interfere with the interferometer 7 are reflected.

It becomes infrared ray 8. The infrared rays 8 are reflected by an edge mirror 9 and sent to a detector 11 by a Cassegrain reflective objective lens 10.
The light is focused on the top. As a result, an interferogram of infrared light emitted from the sample 2 is measured by the detector 11.

〔Example〕

<Example 1> Hereinafter, one example of the present invention will be described with reference to FIG. A sample 2 placed on a sample stage 1 with a heater is heated by the heater and generates infrared rays 3. The flat edge mirror 5 and the concave edge mirror 9 are installed so that they block only half of the optical path and their knife edges are in contact with each other on the optical axis 22. The infrared rays 3 reach the slit 13 by the Cassegrain reflective objective lens 4 and the flat edge mirror 5, and the sample 2
Make statue 14 of. The sample stage 1 with a heater can be moved up and down, so that the image 14 can be formed on the slit 13 by adjusting the height of the sample 2 regardless of the thickness of the sample 2. The infrared rays 3 are reflected by the concave mirror 6 and the mirror in the Michelson interferometer 7, become infrared rays g8, and return onto the slit 13.

Here, the concave mirror 6 is installed so that its first focus is on the slit 13, so that the incident infrared rays 16 and the reflected infrared rays 17 to the interferometer 7 each become parallel rays, and the infrared rays returned from the interferometer 7 8 is the slit 13 again
Make statue 15 on top. Further, the position of the image 14 in the height direction, the angle of incidence of the infrared rays 16 on the interferometer 7, and the position of the image 15 in the height direction are determined by the angle between the flat edge mirror 5 and the optical axis 22. This angle is adjusted so that the infrared light 8 hits the concave edge mirror 9.

The slit 12 is connected from the concave edge mirror 9 to the slit 12.
Distance and plane edge mirror 5. The mirrors are installed so that the distances from the concave edge mirror 9 to the slit 13 are equal. This allows the optical system to be used in common with a conventional one for measuring infrared absorption spectra. Further, the curvature of the concave edge mirror 9 is such that the image on the slit 13 is
determined to be imaged on. Further, the angle between the concave edge mirror 9 and the optical axis 22 is adjusted so that the image of the point where the sample 2 and the optical axis 22 intersect is focused on the point where the slit 12 and the optical axis 22 intersect. The infrared radiation 8 is further imaged onto a detector 11 by a Cassegrain reflective objective 1°.

On the other hand, since the infrared rays 8 include only those interfered by the interferometer 7, the detector 11 can measure the interferogram of the infrared rays emitted from the sample 2.

<Example 2> A second embodiment of the present invention will be explained with reference to FIG.

FIG. 2 is an enlarged view of the objective lens portion of the microscope.

1 is a sample stage with a heater, 2 is a sample, and 4 is a Cassegrain reflective objective lens, which is attached to the revolver 18. The flat edge mirror 5 and the concave edge mirror 9 are installed so that they block only half of the optical path and their knife edges are in contact with each other on the optical axis 22. The flat edge mirror 5 and the concave edge mirror 9 are attached to a mirror moving mechanism 23 and can be moved in and out of the optical path. This allows easy switching between infrared emission spectrum measurement and normal infrared absorption spectrum measurement.

<Example 3> A third embodiment of the present invention will be explained using the third @.

A sample 2 placed on a sample stage 1 with a heater is heated by the heater and generates infrared rays 3. Flat edge mirror 5, 19
is installed so that it blocks only half of the optical path and the knife etches of both are in contact with each other on the optical axis 22. The infrared rays 3 reach the slit 13 by the Cassegrain reflective objective lens 4 and the plane edge mirror 5, and form an image 14 of the sample 2.

The sample stage 1 with a heater can be moved up and down.
Regardless of the thickness of sample 2, adjust the height of sample 2,
An image 14 can be imaged onto the slit 13. The infrared light 4!3 is reflected by the concave mirror 6 and the mirror in the Michelson interferometer 7, becomes infrared light 8, and returns onto the slit 13. Here, the concave mirror 6 is installed so that its first focus is on the slit 13, so that the incident infrared rays 16 and the reflected infrared rays 17 to the interferometer 7 each become parallel rays, and the infrared rays returned from the interferometer 7 8 creates an image 15 on the slit 13 again. Also, the position of the image 14 in the height direction, the infrared ray 1
The angle of incidence of the infrared rays 8 on the interferometer 7 and the position of the image 15 in the height direction are determined by the angle between the flat edge mirror 5 and the optical axis 22.
adjusted to match.

The slit 12 is connected to the slit 1 from the flat edge mirror 19.
The distance from the flat edge mirrors 5 and 19 to the slit 13 is equal to the distance from the flat edge mirrors 5 and 19 to the slit 13. This allows the optical system to be used in common with the conventional one for measuring infrared absorption spectra. Further, the focal length of the convex lens 20 is determined so that the image on the slit 13 is formed on the slit 12.

Further, the angle between the flat edge mirror 19 and the optical axis 22 is adjusted so that the image of the point where the sample 2 and the optical axis 22 intersect is focused on the point where the slit 12 and the optical axis 22 intersect. The infrared radiation 8 is further imaged onto a detector 11 by a Cassegrain reflective objective 10 .

On the other hand, since the infrared rays 8 include only those interfered by the interferometer 7, the detector 11 can measure the interferogram of the infrared rays emitted from the sample 2.

<Example 4> FIG. 4 is an enlarged view of the microscope objective lens portion.

1 is a sample stage with a heater, 2 is a sample, and 4 is a Cassegrain reflective objective lens, which is attached to a revolver 18. The plane edge mirror 5.19 blocks only half of the optical path, and is MWed such that both knife edges touch on the optical axis 22.

The flat edge mirrors 5, 19 and the convex lens 2o are attached to a mirror moving mechanism 23 and can be moved in and out of the optical path. This allows easy switching between infrared emission spectrum measurement and normal infrared absorption spectrum measurement.

<Embodiment 5> FIG. 5 shows a fifth embodiment of the present invention. This is a modification of the first embodiment in which the concave edge mirror 9 is moved along the optical axis 22 to the opposite side from the flat edge mirror 5. In the first embodiment, only half of the optical path is blocked by the plane edge mirror 5, so the infrared rays passing through the other half of the optical path do not pass through the interferometer 7, but directly enter the detector 11, resulting in a measurement back. Becomes grand. However, in this embodiment, the infrared rays that do not hit the flat edge mirror 5 are also blocked by the back side of the concave edge mirror 9, so that they do not enter the detector 11. Therefore, compared to the first embodiment.

The S/N ratio of measurement can be improved.

<Embodiment 6> FIG. 6 shows a sixth embodiment of the present invention. This is a modification of the second embodiment in which the plane edge mirror 19 is moved to the opposite side of the plane edge mirror 5 with respect to the optical axis 22. In the first embodiment, only half of the optical path is blocked by the flat edge mirror 5, so the infrared rays passing through the other half of the optical path do not pass through the interferometer 7, but directly enter the detector 11, and are directly incident on the measurement bank. Becomes grand. However, in this embodiment, the infrared rays that do not hit the flat edge mirror 5 are also blocked by the back side of the flat edge mirror 19, so that they do not enter the detector 11. Therefore, the S/N ratio of measurement can be improved compared to the second embodiment.

〔Effect of the invention〕

According to the present invention, an image of infrared rays emitted from a minute portion of a heated sample is captured as a face v1. It is possible to magnify it with a mirror, modulate it with an interferometer, and measure the ink ferrogram with a detector.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the first embodiment of the microscopic infrared emission spectrophotometer according to the present invention, FIG. 2 is an explanatory diagram of a part of the edge mirror of the second embodiment of the present invention, and FIG. FIG. 4 is an explanatory diagram showing a third embodiment of the invention. FIG. 4 is an explanatory diagram of a part of the edge mirror of the fourth embodiment of the invention. FIG. FIG. 6 is an explanatory diagram showing a sixth embodiment of the present invention, and FIGS. 7 to 9 are explanatory diagrams of conventional examples according to the present invention. 1... Sample stand with heater, 2... Sample, 3, 8, 16
．． 17...Infrared rays, 4,10...Cassegrain type reflective objective lens, 5,19...Plane edge mirror, 6...
Concave mirror, 7... Interferometer, 9... Concave edge mirror
11...Detector, 12.13...Slit, 14.
15... Image, 18... revolver, 20... convex lens, 21... telescope, 22... optical axis, 23...
・Mirror movement mechanism, 28... switching plane mirror, 31.
...Sample stage, 32°32''...Aperture, 33...
・Capacitor. A compilation of illustrations

Claims (1)

[Claims] 1. In a microinfrared spectrophotometer consisting of a Fourier transform spectrophotometer, a reflection type microscope, and a detector, a flat surface that reflects light from an objective lens toward the Fourier transform spectrophotometer. A microscopic spectrophotometer comprising: a reflecting mirror; and an ellipsoidal or concave reflecting mirror that reflects light from the Fourier transform spectrophotometer toward a detector. 2. The microscopic spectrophotometer according to claim 1, wherein a mirror moving mechanism is attached to the plane reflecting mirror so that it can be moved in and out of the optical path. 3. In claim 1, a plane mirror is provided in place of the ellipsoidal or concave reflecting mirror, and a condenser consisting of a convex lens, an ellipsoidal, concave, parabolic mirror, or a combination thereof is provided between the plane mirror and the detector. A microscopic spectrophotometer equipped with an optical system using 4. The microscopic spectrophotometer according to claim 3, wherein a mirror moving mechanism is attached to the plane mirror and the condenser so that the mirror can be moved in and out of the optical path.