JP2000121553A - Infrared microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared microscope in which a polarizer is moved and rotated in an optical path by the slit operation of a variable aperture. SOLUTION: The variable aperture 50 is constituted of a pair of slits 21 movable in a casing 22 in Y-direction and a slit 20 on one hand and a slit 24 with a polarizer on which a polarizer is mounted on the other hand in X- direction. Since an aperture 23 is formed at the center by the movement of each slit, it is possible to limit the field of view of infrared measurement. Since the slit 24 with a polarizer in which a polarizer is mounted on one slit can be moved to the center of the aperture 23, it is possible to observe polarization with visible light by a polarizer by mounting an infrared micro-spectral or visible light polarizer at this time. Since the slit 24 with a polarizer can be rotated together with the casing 22, it is possible to catch information from a sample at the angle of polarization. A mechanism capable of automatic operation by an external force such as a motor under the control of a personal computer is provided. However, it is possible to release the mechanism and to operate manually.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared microscope, and more particularly to a slit for limiting a field of view for infrared measurement of an apparatus for performing microspectroscopy in an infrared wavelength region.

[0002]

2. Description of the Related Art An infrared microscope is a device that performs microspectroscopy in the infrared wavelength region, and is a microscope designed to focus an infrared light beam on a very small area so as to be suitable for a small sample. Up to 30 times. However, in recent years, microscopes utilizing the enhanced sensitivity of Fourier transform infrared spectroscopy have been developed, and a microscopic system combining a Fourier transform infrared spectrophotometer and an infrared microscope has a spatial resolution of about 10 μm.
It is. Since infrared microscopes can be analyzed nondestructively at room temperature and normal pressure, the range of samples that can be measured is wide. It is used for analysis of fine particles, foreign substances and defects in materials, composition analysis of composite materials, research on biological tissues, research on material composition, structure, crystallinity, anisotropy of molecules and crystals, and the like. One example of the principle is that infrared light from an interferometer of a Fourier transform infrared spectrophotometer is guided to an infrared microscope through a reflecting mirror, and is focused on a sample by using a concave mirror to about 1 mm. Objective mirror is Cassegrain type 10-4
It has a magnification of about 0 times. In order to detect only the light transmitted through the sample, a stop (variable aperture) is placed on the sample portion or the image forming portion, and the light passing through the stop (variable aperture) is condensed and a small area semiconductor detector (MCT) And an infrared spectrum is obtained by Fourier transform. FIG. 4 shows an example of an infrared microscope used in combination with a conventional Fourier transform infrared spectrophotometer 60. This apparatus can be used in either a transmission method or a reflection method. In the case of using the transmission method, infrared light from the Michelson interferometer of the Fourier transform infrared spectrophotometer 60 is reflected by the transmission / reflection switching mirror 10 and reflected by the reflection mirrors 37, 3 below the figure.
The light passes through the reflecting mirror 31 and is reflected by the reflecting mirror 32 via the reflecting mirror 32, enters the condensing mirror 7, is narrowed down to about 1 mm, and hits the sample on the sample stage 6. On the other hand, the light transmitted through the sample is
The light is condensed by the reflecting objective mirror 4 having a magnification of about 15 and passes through the reflecting mirror 33, passes through the variable aperture 3 and the reflecting mirror 38, and is condensed by the concave reflecting mirror 41 via the reflecting mirrors 39 and 40. The light enters the MCT detector 11 having a small area and is detected.
The detected signal is Fourier transformed into an infrared spectrum. When used in the reflection method, infrared light from the Michelson interferometer of the Fourier transform infrared spectrophotometer 60 is transmitted /
The reflection mirrors 34 and 3 which are reflected by the reflection switching mirror 10 and
The light is reflected by the reflecting mirror 5, reflected by the reflecting mirror 33, enters the reflecting objective mirror 4, is squeezed to about 1 mm, and hits the sample on the sample stage 6. On the other hand, the light reflected from the sample is collected by the reflecting objective mirror 4 having a magnification of about 15 and transmitted through the reflecting mirror 33,
The light passes through the variable aperture 3, passes through the reflecting mirror 38, is condensed by the concave reflecting mirror 41 through the reflecting mirrors 39 and 40, enters the MCT detector 11 having a small area, and is detected. The detected signal is Fourier transformed into an infrared spectrum. Usually, since the size of the sample is smaller than the entire field of view, masking is performed by the variable aperture 3 in accordance with the sample. Further, transmission measurement and reflection measurement can be easily selected by switching the transmission / reflection switching mirror 10. In the case of the transmission method, it is necessary to collect a small sample and manufacture a thin section. In the reflection method, the amount of light is insufficient due to scattering, and the shape of the absorption band is distorted due to the effect of specular reflection.Therefore, this method is not used for general samples. In exceptional cases, there is an advantage that the optical path length is doubled by reflection, and measurement can be performed with the same spatial resolution as the transmission method. Also, the sample stage 6 is scanned by a microcomputer to perform three-dimensional mapping of the material surface. On the other hand, when observing the visible image of the sample with eyes, photographing, or observing with a TV monitor, when observing with transmitted light, the light from the halogen lamp 8 for transmission observation illumination is reflected. The mirror 31 and 32 impinge on the sample on the sample stage 6 by the condenser mirror 7, and the transmitted light passes through the reflecting objective mirror 4 and the reflecting mirror 33, passes through the variable aperture 3, and is reflected by the reflecting mirror 38. The sample image is reflected by the prism 43 and observed from the eyepiece lens 2. Further, a photographing camera or a TV camera is attached to the photographing device mounting opening 1 to photograph or photograph. When observing with reflected light, light from the halogen lamp 12 for reflection observation illumination is
The light is reflected by the reflecting mirror 42, reflected by the reflecting mirror 38, passes through the variable aperture 3, passes through the reflecting mirror 33, and is reflected by the reflecting objective mirror 4
The reflected light is focused by the reflecting objective mirror 4, passes through the reflecting mirror 33, passes through the variable aperture 3, and is reflected by the reflecting mirror 38.
The sample image is reflected by the prism 43 and observed from the eyepiece lens 2. In addition, a photographing camera or a TV camera is attached to the photographing device mounting opening 1 to photograph or photograph.

[0003]

The conventional infrared microscope is constructed as described above. However, in order to perform infrared measurement of a minute sample, the infrared light passing through the measured portion is compared with other portions. In order to separately introduce the light into the infrared detector, a XY variable size slit mechanism called a variable aperture 3, which is rotatable as a whole, is usually employed. FIG. 5 shows the variable aperture 3
3A and 3B are a top view and a side view, respectively. A set of slits 21 that can move in the Y direction (up and down)
A set of slits 20 movable in the direction (left and right) is provided. The field of view (aperture 23) of the sample is limited by the slits 21 and 20. The variable aperture 3 is set so as to rotate as a whole around the optical axis. The setting and rotation of the visual field are performed manually / automatically. As described above, each of the variable apertures 3 has only a single function. When a polarizer or the like is separately used to obtain information on a polarization angle from a sample, a separate holder is inserted into a position on another optical axis. It has been done. Therefore, a separate polarizer holder is required, which complicates the operation. For example, there has been a problem that operation mistakes such as forgetting to remove the polarizer from the optical axis and forgetting to rotate the polarizer are caused.

The present invention has been made in view of such circumstances, and in order to obtain information on a polarization angle from a sample, a holder is separately inserted on another optical axis using a polarizer or the like. It is an object of the present invention to provide an infrared microscope that does not require such a troublesome operation.

[0005]

In order to achieve the above object, an infrared microscope according to the present invention detects only light transmitted or reflected by a small sample in an infrared wavelength region by focusing light on a very small area with a concave mirror. A slit that limits the field of view for infrared measurement is placed on the sample or imaging part, and the light that has passed through the aperture of the slit is condensed and the microscopic light detected by the semiconductor detector and the visible image are observed. In the infrared microscope, a polarizer is mounted on the slit, and a mechanism capable of inserting and rotating the polarizer on the optical axis is provided.

Further, the infrared microscope according to the present invention is characterized in that, in the infrared wavelength region, light is focused on a very small area by a concave mirror and only light transmitted or reflected on a minute sample is detected. Place an slit to limit the field of view of the measurement, micro-spectroscopy light that passes through the aperture of the slit is collected and detected by a semiconductor detector, and in an infrared microscope that can observe a visible image, the slit And a mechanism capable of automatically inserting and rotating the polarizer on the optical axis by an external force such as a motor.

The infrared microscope of the present invention is configured as described above. A polarizer is mounted on a slit of a variable aperture that limits the field of view of infrared measurement, and the polarizer is moved in and out of the optical axis to make it visible. A mode for inserting a polarizer can be added in addition to a (air) mode that is normally opened during observation and infrared microspectroscopy. Then, a separate polarizer holder is not required, and operation errors such as forgetting to remove the polarizer from the optical axis and forgetting to rotate the polarizer can be eliminated.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the infrared microscope according to the present invention will be described with reference to FIGS. As shown in FIG. 1, the infrared microscope of the present invention can use either the transmission method or the reflection method. The variable aperture 3 of the conventional infrared microscope (shown in FIG. 4) is replaced with the variable aperture 5.
It has been replaced by zero. As shown in FIG. 2, the variable aperture 50 has a pair of slits 21 movable in the Y direction (up and down) inside the housing 22, one slit 20 in the X direction (left and right), and a polarizer mounted on the other. And a slit 24 with a polarizer. The aperture 23 is formed at the center by the movement of each slit, and the variable aperture 50 can be rotated around the aperture 23 together with the housing 22, so that the field of view for infrared measurement can be limited. This state is a normal open mode. In the present invention, as shown in FIG. 3, a slit 24 with a polarizer having a polarizer mounted on one of the slits has an aperture 23.
At that time, the opposing slit 20 moves to the left end, and the polarizer of the slit with polarizer 24 moves the optical axis so that the visible image observation and the infrared microspectroscopy can be performed by the polarizer. to go into. And the variable aperture 50
Can rotate the slit with polarizer 24 together with the housing 22. Therefore, information from the sample can be captured by the polarization angle. If the image with the polarizer in it is stored in a personal computer and the size of the aperture 23 is specified for the image, infrared microscopic measurement of the sample observed by polarization can be performed. Thus, the slit 20,
The X and Y movements of the slit 21 and the polarizer-equipped slit 24 can move independently and horizontally, and the aperture 23 and the polarizer-equipped slit 24 can rotate about the optical axis. Therefore, a mask can be applied to an amorphous sample. As the driving force, for example, it can be driven by a combination of a feed screw and a stepping motor.
Then, by controlling the CPU, for example, the size and the angle specified by the personal computer can be automatically set. A mechanism that can be performed automatically by an external force such as a motor, and a mechanism that can be manually performed by releasing this mechanism. Insertion of polarizer by the above mechanism,
Rotation can be easily performed, and a mode in which a polarizer is inserted and a normal open mode can be switched for use. As described above, the variable aperture 50 has conventionally been used only for limiting the visual field of infrared light, which is the original purpose. However, by attaching a polarizer to this variable aperture, it is possible to easily cope with polarization measurement.

Next, how to use the infrared microscope of the present invention in combination with the Fourier transform infrared spectrophotometer 60 will be described. In the case of using the transmission method, infrared light from the Michelson interferometer of the Fourier transform infrared spectrophotometer 60 is reflected by the transmission / reflection switching mirror 10 and reflected by the reflection mirrors 37, 3 below the figure.
The light is transmitted through the reflecting mirror 31 through the reflecting mirror 32, is reflected by the reflecting mirror 32, enters the condensing mirror 7, is narrowed down to about 1 mm, and hits the sample on the sample stage 6. On the other hand, the light transmitted through the sample is condensed by the reflection objective mirror 4 having a magnification of about 15 times, transmitted through the reflection mirror 33, and condensed at the position of the variable aperture 50. When performing measurement using a polarizer, the slit 24 with a polarizer of the variable aperture 50 is set at this position (automatic / manual). The transmitted light passes through the reflecting mirror 38, is condensed by the concave reflecting mirror 41 via the reflecting mirrors 39 and 40, and is detected by entering the MCT detector 11 having a small area. The detected signal is Fourier transformed into an infrared spectrum. When used in the reflection method, infrared light from the Michelson interferometer of the Fourier transform infrared spectrophotometer 60 is reflected by the transmission / reflection switching mirror 10 and reflected by the reflection mirror 3 above the figure.
The reflection objective mirror 4 reflects at 4, 35 and reflects at the reflecting mirror 33.
And is squeezed to about 1 mm to hit the sample on the sample stage 6. On the other hand, the light reflected from the sample has a magnification of 15
The light is condensed by the reflection objective mirror 4 having a magnification of about twice, passes through the reflection mirror 33, and is condensed at the position of the variable aperture 50. When performing measurement using a polarizer, the slit 24 with a polarizer of the variable aperture 50 is set at this position (automatic / manual). Then, the transmitted light passes through the reflecting mirror 38 and is condensed by the concave reflecting mirror 41 via the reflecting mirrors 39 and 40, and enters the MCT detector 11 having a small area and is detected. The detected signal is Fourier transformed into an infrared spectrum. Next, a method of using the infrared microscope of the present invention for observing a visible image of a sample with eyes, photographing, and observing with a TV monitor will be described. When observation is made with transmitted light, light from the halogen lamp 8 for transmission observation illumination is reflected by the reflecting mirrors 31 and 3.
When the light is applied to the sample on the sample stage 6 by the condensing mirror 7 by 2, the transmitted light is condensed by the reflecting objective mirror 4, passes through the reflecting mirror 33, passes through the variable aperture 50, and is used for observation by the polarizer. The slit 24 with polarizer of the variable aperture 50 is set (automatic / manual) at this position. Then, the transmitted light is reflected by the reflecting mirror 38 and reflected by the prism 43, and the sample image is observed from the eyepiece 2. In addition, a photographing camera or a TV
A camera is attached, and photography or imaging is performed.
When observing with reflected light, the light from the halogen lamp 12 for reflection observation illumination is reflected by the reflecting mirror 42, reflected by the reflecting mirror 38, passes through the variable aperture 50, and is changed when the observation by the polarizer is performed. The slit 24 with the polarizer of the aperture 50 is set (automatic / manual) at this position.
The transmitted light passes through the reflecting mirror 33 and passes through the reflecting objective mirror 4 to be applied to the sample on the sample stage 6. The reflected light is condensed by the reflecting objective mirror 4 and transmitted through the reflecting mirror 33. Variable aperture 50, or variable aperture 50
Is reflected by the reflecting mirror 38 and reflected by the prism 43, and the sample image is observed from the eyepiece 2. In addition, a photographing camera or a TV camera is attached to the photographing device mounting opening 1 to photograph or photograph.

[0010]

According to the infrared microscope of the present invention, the polarizer is mounted on the slit of the variable aperture for limiting the field of view of the infrared measurement, and the polarizer is easily inserted into the optical axis. By enabling the rotation, not only a normal open (air) mode for visible observation but also a mode for inserting a polarizer can be added. Then, a separate polarizer holder is not required, and operation errors such as forgetting to remove the polarizer from the optical axis and forgetting to rotate the polarizer can be eliminated.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of an infrared microscope of the present invention.

FIG. 2 is a view showing a variable aperture of the infrared microscope of the present invention.

FIG. 3 is a diagram illustrating a state where a polarizer of a variable aperture has moved to an optical axis.

FIG. 4 is a diagram showing a conventional infrared microscope.

FIG. 5 is a diagram showing a variable aperture of a conventional infrared microscope.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image pick-up device mounting opening 2 ... Eyepiece 3 ... Variable aperture 4 ... Reflective objective mirror 5 ... Visible objective lens 6 ... Sample stage 7 ... Condensing mirror 8 ... Halogen lamp for transmission observation illumination 9 ... Focus adjustment dial 10 ... Transmission / Reflection switching mirror 11 MCT detector 12 Halogen lamp for reflection observation illumination 20 Slit 21 Slit 22 Housing 23 Aperture 24 Slit with polarizer 31, 32, 3
3 ... Reflecting mirror 34,35,36,37 ... Reflecting mirror 38,39,4
0, 41: Reflecting mirror 42: Reflecting mirror 43: Prism 50: Variable aperture 60: Fourier transform infrared spectrophotometer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) MM10 PP01

Claims (2)

[Claims] 1. A slit which restricts a field of view of an infrared measurement in a sample portion or an image forming portion, in which a light is narrowed down to a very small area by a concave mirror in an infrared wavelength region and only light transmitted or reflected on a minute sample is detected. In the infrared microscope where light passing through the aperture of the slit is collected and detected by a semiconductor detector and microscopic light can be observed, a polarizer is mounted on the slit, and an optical axis is provided. An infrared microscope comprising a mechanism that allows a polarizer to be inserted and rotated in a microscope. 2. A slit for limiting the field of infrared measurement in a sample portion or an image forming portion, wherein the light is focused to a very small area by a concave mirror in the infrared wavelength region and only light transmitted or reflected on a minute sample is detected. In the infrared microscope which can observe microscopic light, which is collected by the semiconductor detector and light which passes through the aperture of the slit, and which can observe a visible image, a polarizer is mounted on the slit, and An infrared microscope having a mechanism capable of automatically inserting and rotating a polarizer on a shaft by an external force of a motor or the like.