JPH09210904A - Microscopic observation method of infrared transmission image and contact microscope - Google Patents

Abstract

(57) [Abstract] [Problem] Infrared light image containing spatial distribution information of chemical substances,
Obtaining with spatial resolution of visible light wavelength. An optical microscope for visible light, which projects infrared light onto a sample in close contact with the surface of an infrared / visible light converting thin film, converts the infrared light transmission image into a visible light image in a near-field region of the sample, and Observe at.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION Since a monochromatic infrared transmission image contains information on chemical substances, two-dimensional chemical analysis of a sample can be performed from the infrared image. The present invention relates to a method of microscopically observing this infrared light transmission image and a contact microscope.

[0002]

2. Description of the Related Art In order to obtain an infrared light transmission image, a sample is scanned with an optical microscope composed of an optical system made of a material that refracts or reflects infrared light, or a finely focused infrared light beam. This is possible with any type of scanning microscope. However, the spatial resolution of a far-field image observed by an optical microscope or a converged beam is limited to about λ / 2 of the used wavelength due to Rayleigh's diffraction limit.

[0003]

Infrared light contains information relating to chemical information, but since it has a longer wavelength than visible light, the spatial resolution of infrared images is inevitably inferior. Therefore, an object of the present invention is to provide a means for obtaining an infrared image with a spatial resolution similar to that of a visible light image.

[0004]

According to the present invention, an infrared light image transmitted through a sample to be observed is projected on an infrared / visible light conversion plate arranged in a substantial near-field region of the sample and converted. By observing the obtained visible light image with a normal optical microscope for visible light, it becomes possible to obtain an infrared light image with a spatial resolution limited by the wavelength of visible light.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The infrared / visible light converting material used in the present invention is an alkaline earth chalcogen fluorescent substance containing two kinds of rare earths such as europium, cerium and samarium as impurities. FIG. 1 shows the principle. The energy levels of both rare earths lie between the valence band 1 and the conduction band 2 of the host material. When the ultraviolet light 3 is irradiated, the electrons 5 in the ground state 4 of the rare earth 1 are excited to the high energy level 6 of the rare earth 1 and finally transition to the ground state 7 of the rare earth 2. This condition is stable. Next, when the infrared light 8 is irradiated, the electrons in the ground state 7 of the rare earth 2 are excited to the high energy level 9 of the rare earth 2 and finally return to the ground state 4 of the rare earth 1. In this process, visible light 10 is emitted. That is, visible light corresponding to infrared light is obtained by irradiating infrared light while being excited by ultraviolet light.

Therefore, as shown in FIG. 2, the infrared / visible light conversion material is converted into infrared rays by the alkaline earth chalcogen fluorescent substance containing two kinds of rare earths such as europium, cerium and samarium as impurities and the host material. / Constituting the visible light conversion material thin film 11, irradiating this with the ultraviolet light 12, and then projecting the infrared light image 13, the visible light imaging system 14
The visible light image 15 can be obtained by using.

First Embodiment FIG. 3 shows a conceptual diagram of the configuration of the first embodiment. The thin sample 1 is placed on the infrared / visible light conversion material thin film 17 irradiated with the ultraviolet light 16.
8 are brought into close contact with each other, and monochromatic infrared light 19 is irradiated. as a result,
The infrared light transmission image 21 including the spatial distribution information of the chemical substance 20 to be observed in the sample is projected on the infrared / visible light conversion material thin film 17. The infrared light transmission image 21 is wavelength-converted by the infrared / visible light conversion material thin film 17, separated as a visible light image 22 containing chemical information via a dichroic mirror 23, and has a high spatial resolution by an imaging system 24 for visible light. Is imaged at.

In this embodiment, the sample 18 is the conversion material thin film 1
Due to its close contact with 7, the spatial resolution of the projected image is determined by that of the near field and is much higher than in the far field.

In this embodiment, the irradiation of the ultraviolet light 16 is not substantially influenced by the spatial distribution information of the chemical substance 20 distributed in the sample 18. Therefore, even if the ultraviolet light 16 is irradiated after the sample 18 is set on the conversion material thin film 17, excitation of the infrared / visible light conversion material thin film 17 is performed substantially uniformly, and there is no problem.

Second Embodiment FIG. 4 shows a conceptual diagram of the configuration of the second embodiment. A thin sample 26 was brought into close contact with the infrared / visible light conversion material thin film 25. After the thin film 25 is irradiated with the ultraviolet light 27, the thin film 2 is formed by using the half mirror 28, the total reflection mirror 29, and the dichroic mirrors 30 and 50.
Irradiate the coherent infrared light 31 from both sides of the thin film 2
Interference in 5. Here, the dichroic mirror 30 substantially acts as a reflecting mirror for infrared light and has a sufficient transmittance for the ultraviolet light 27. Further, the dichroic mirror 50 substantially acts as a reflecting mirror for infrared light and has a sufficient transmittance for visible light 33. As a result, the infrared light image including the phase information due to the spatial distribution of the chemical substance of the sample 26 was converted into visible light, and the visible light image forming system 32 formed the visible light image 33.

Also in this embodiment, the irradiation of the thin film 25 with the ultraviolet light 27 does not matter before and after the setting of the sample 26.

Example 3 FIG. 5 shows a configuration example of a microscope for observing an infrared light transmission image with a visible light optical microscope according to the concept of Example 1. In the figure, 34 is a sample stage, 35 is an infrared / visible light conversion material thin film, 36 is a sample, 37 is an ultraviolet light source, 38 is ultraviolet light, 39 is a total reflection mirror, 40 is an infrared light source, 41 is red. External light, 42 is a dichroic mirror, 43 is a long focus objective lens, and 44 is an eyepiece lens. After the infrared / visible light conversion material thin film 35 and the sample 36 are set on the sample stage 34, ultraviolet light 38 is emitted from the ultraviolet light source 37, and the total reflection mirror 3
The infrared / visible light conversion material thin film 35 is excited via 9. Thereafter, infrared light 41 is emitted from the infrared light source 40, and the infrared light 41 is transmitted to the sample 36 via the dichroic mirror 42.
Is irradiated. As a result, the infrared / visible light conversion material thin film 35
By observing the visible light image generated from the sample through the long-focus objective lens 43 and the eyepiece lens 44, information on the distribution of the two-dimensional chemical substance of the sample 36 can be obtained.

Embodiment 4 FIG. 6 shows an example of the configuration of a microscope for observing an infrared light transmission image with a visible light optical microscope according to the concept of Embodiment 2. In FIG. 6, a sample stage 34, an infrared / visible light conversion material thin film 35, a sample 36, an ultraviolet light source 37, an ultraviolet light 38,
The total reflection mirror 39, the infrared light source 40, the infrared light 41, the dichroic mirror 42, the long focus objective lens 43, and the eyepiece lens 44 are the same as those in FIG. In this embodiment, since it is necessary to irradiate the coherent infrared light from both sides of the infrared / visible light conversion material thin film 35 to cause interference, the half mirror 45 is placed in the optical path of the infrared light, and the infrared reflected by this is reflected. A dichroic mirror 4 that places light in the optical path of ultraviolet light.
Reflected by 6. Here, the dichroic mirror 46 substantially acts as a reflecting mirror for the infrared light 41 and has a sufficient transmittance for the ultraviolet light 38. Reference numeral 47 is a through hole provided in the sample stage 34 for an optical path of infrared light.

After the infrared / visible light conversion material thin film 35 and the sample 36 are set on the sample stage 34, ultraviolet light 38 is emitted from an ultraviolet light source 37, and a dichroic mirror 46 and a total reflection mirror 39 are passed through. Infrared / visible light conversion material thin film 3
Excite 5. Then, from the infrared light source 40 to the infrared light 41
And irradiates the sample 36 with infrared light 41 via the dichroic mirror 42 via the half mirror 45, and via the total reflection mirror 39 via the half mirror 45 and the dichroic mirror 46. The infrared light 41 is radiated on. As a result, phase information based on the spatial distribution of the chemical substance of the sample 36 is obtained via the long-focus objective lens 43 and the lens eyepiece lens 44.

In the above embodiment, the sample is directly
Although the example of placing it on the infrared / visible light conversion material thin film has been described, it is also possible to place the sample on the infrared / visible light conversion material thin film after holding the sample on a thin holding film for convenience of handling the sample. good. In this case, if the sample is brought into direct contact with the infrared / visible light conversion material thin film, it is convenient because the sample and the infrared / visible light conversion material thin film are closer to each other.

[0016]

According to the present invention, an image containing transmittance or phase information in the infrared light region of a sample can be obtained with a spatial resolution of visible light wavelength, and high spatial resolution and spatial distribution information of a chemical substance can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing the principle of an infrared / visible light conversion material.

FIG. 2 is a diagram showing how an infrared light image is converted into a visible light image.

FIG. 3 is a diagram showing how an infrared light transmission image of a closely attached sample is converted into a visible light image in a near field region of the sample.

FIG. 4 is a view showing a state in which an infrared light phase image of a closely attached sample is converted into a visible light image in a near field region of the sample.

FIG. 5 is a diagram showing how an infrared light transmission image of a sample is observed with an optical microscope for visible light.

FIG. 6 is a diagram showing how an image including phase information of a sample is observed with an optical microscope for visible light.

[Explanation of symbols]

1 ... Valence band, 2 ... Conduction band, 3 ... Ultraviolet light, 4 ... Rare earth 1
Ground state, 5 ... Electron, 6 ... High energy level of rare earth 1, 7 ... Ground state of rare earth 2, 8 ... Infrared light, 9 ... High energy level of rare earth 2, 10 ... Visible light, 11 ... Red Outer / visible light conversion material thin film, 12 ... Ultraviolet light, 13 ... Infrared light image, 1
4 ... Imaging system for visible light, 15 ... Visible light image, 16 ... Ultraviolet light,
17 ... Infrared / visible light conversion material thin film, 18 ... Sample, 19 ...
Monochromatic infrared light, 20 ... Chemical substance to be observed in sample, 21 ... Infrared light transmission image, 22 ... Visible light image, 23 ... Dichroic mirror, 24 ... Visible light imaging system, 25 ... Infrared / visible conversion material Thin film, 26 ... Sample, 27 ... Ultraviolet light, 28 ... Half mirror, 29 ... Total reflection mirror, 30, 50 ... Dichroic mirror, 31 ... Infrared light, 32 ... Visible light imaging system, 33 ... Visible light image, 34 ... Sample stage, 35 ... Infrared / visible light conversion material thin film, 36 ... Sample, 37 ... Ultraviolet light source, 38 ... Ultraviolet light, 39 ... Total reflection mirror, 40 ... Infrared light source, 41 ... Infrared light, 42 ... dichroic mirror, 43 ... long focus objective lens, 44 ... eyepiece lens, 45 ... half mirror, 46 ...
Dichromic mirror, 47 ... Through hole for optical path.

Claims (5)

[Claims] 1. An infrared / visible light conversion film containing a plurality of rare earths is excited by ultraviolet light, and the conversion film is irradiated with infrared light through a sample placed on the conversion film. An observation method comprising microscopically observing a visible light image obtained from the conversion film. 2. An infrared / visible light conversion film containing a plurality of rare earths is excited by ultraviolet light, and the conversion film is irradiated with coherent infrared light through a sample placed on the conversion film, Irradiating coherent infrared light from the other surface of the conversion film to cause both coherent infrared light to interfere in the conversion film, and microscopically observing a visible light image including phase information obtained from the conversion film. The observation method that consists of. 3. The observation method according to claim 1, wherein the plurality of rare earth elements are europium, cerium, and samarium. 4. A sample stage, an infrared ray containing a plurality of rare earth elements placed on the sample stage, and a sample is placed on a part of the sample stage.
Visible light converting material thin film, ultraviolet light source for exciting the infrared / visible light converting material thin film with ultraviolet light, and irradiating the infrared / visible light converting material thin film after the excitation with infrared light through a sample Infrared light source, an ultraviolet light source, a reflecting means for forming a predetermined optical path of the ultraviolet light and the infrared light emitted from the infrared light source, and visible light obtained in the infrared / visible light conversion material thin film A contact microscope comprising a means for observing an image. 5. The contact microscope according to claim 4, wherein the plurality of rare earths are europium, cerium, and samarium.