JP2001296415A - Spectral device and far ir spectral device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spectral device having a blaze grating pattern formed in several hundreds μm order for any desired forms. SOLUTION: The optical device to obtain specified wavelength spectrum is equipped with a diffraction grating and is produced by laminating and fixing a plurality of thin plates 10 each having several hundreds μm order thickness with the faces of adjacent thin plates in contact with each other so that the grooves are formed on the edges of the thin plates to act as a diffraction grating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a spectroscopic element and a far-infrared spectroscopic device. More specifically, the present invention relates to a new spectroscopic element realized by forming grooves of a diffraction grating having various shapes including a curved surface on the order of several hundred μm or less, and a far-infrared spectroscopic device using the same.

[0002]

2. Description of the Related Art Conventionally, diffraction gratings have been widely used as optical elements for obtaining a spectrum using light diffraction.

A diffraction grating used for spectroscopy for long-wavelength light such as far-infrared rays is generally produced by cutting a metal surface or etching it with an ion beam. As a method of fabricating a diffraction grating having a complicated shape such as a curved surface structure, a method of directly etching a resist on a substrate by using an electron beam or a laser beam and changing its dose ( For example, M. Haruna et.al., pp1, Opt, Vol. 29, pp. 5120,
1990) and a method of using an organic material containing a light absorber having a varied thickness as a photomask having a modulated transmittance (Japanese Patent Application Laid-Open No. 63-271265).
By using these methods, not only a blazed diffraction grating inclined in one direction but also the direction of the blaze can be arbitrarily determined, and a blaze grating pattern with a high degree of freedom can be generated.

[0004] However, in the above-described conventional method, since strict production conditions are required, it has been difficult to generate a blazed grating pattern with an accuracy on the order of several hundreds of μm.

Accordingly, the invention of this application has been made in view of the above circumstances, and a new spectroscopic element having a blazed grating pattern formed on the order of several hundred μm in an arbitrary shape and a new spectroscopic element have been proposed. It is an object of the present invention to provide a used spectroscopic device.

[0006]

Means for Solving the Problems The present invention solves the above-mentioned problems. First, the present invention relates to a spectroscopic element having a diffraction grating for obtaining light of a specific wavelength spectrum, Multiple thin plates with a thickness of the order of several hundred μm,
A spectroscopic element is provided, in which adjacent thin plates are fixed in an overlapped state so that the surfaces are in contact with each other, whereby a groove is formed at an end of the thin plate to form a diffraction grating.

Secondly, the invention of this application relates to a spectral element having a diffraction grating for obtaining light of a specific wavelength spectrum, wherein a plurality of thin plates having a thickness of the order of several hundred μm are provided. A spectroscopic element characterized in that the surfaces of adjacent thin plates are overlapped so as to be in contact with each other, and the thin plates are fixed in a state where the thin plates are shifted so that the surface formed by the ends of the thin plates becomes a curved surface. I do.

Further, the invention of this application is, thirdly, a spectroscopic element provided with a diffraction grating for obtaining light of a specific wavelength spectrum, wherein a plurality of thin plates having a thickness on the order of several hundred μm are provided. Then, the surfaces of adjacent thin plates are overlapped and fixed so that the surfaces come into contact with each other, and the surface formed by the ends of the thin plates is cut into a curved surface, and the blaze angle is formed on the curved surface formed by the ends of the thin plates. The spectroscopic element is also characterized in that the thin plates are fixed in such a manner that they are periodically shifted.

Fourth, the invention of the present application provides a far-infrared spectroscopic device characterized by including any one of the above-described spectroscopic elements.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention of this application has the features as described above, and embodiments thereof will be described below.

The spectral element according to the invention of this application is useful for obtaining light of a specific wavelength spectrum with respect to light in a super-wavelength band such as far-infrared rays, and the light is separated by a diffraction grating provided. In the invention of this application, the definition of “thickness of several hundred μm” as the thickness of the thin film means that the thickness is up to about 600 μm and further up to 400 μm. Therefore, it is sufficient if the thickness is less than these.

In the diffraction grating used in this spectroscopic element, a plurality of thin plates having a thickness on the order of several hundreds of μm are arranged in a state of being overlapped so that the respective surfaces of adjacent thin plates are in contact with each other, and fixed by a holder. It is formed by things. At this time, as shown in FIG. 1, for example, a diffraction grating is formed by periodically changing the overlapping position of the thin plate (10). Alternatively, as shown in FIG. 2, the thin plate (20) may be processed so that a blaze angle is formed at an end portion thereof, and these may be overlapped to form a diffraction grating to be a blaze grating. Further, as shown in FIG. 3, the blaze angle can be set to an arbitrary angle by inclining and fixing the thin plate (30) with the folder (31).

In the spectral element of the invention of this application, a plurality of thin plates are overlapped so that the surfaces of adjacent thin plates are in contact with each other, and then the thin plates are fixed while being shifted.
As shown in (5), the surface formed by the end of the thin plate (40) may be formed to be a curved surface. In addition, as shown in FIG. 5, a plurality of thin plates (50) are overlapped and fixed in advance so that the surfaces of the thin plates are in contact with each other, and the surface formed by the ends of the thin plates (50) is formed into a shape. By cutting (A) and periodically shifting the thin plate (50) (C), a blaze angle may be formed on a curved surface formed by the ends of the thin plate.

As described above, the spectral element according to the invention of this application is fundamentally different from a conventional diffraction grating manufactured by forming a groove on the surface of a metal plate. The main point is that the lattice pattern is formed by overlapping a plurality of thin plates. The pattern of the diffraction grating to be formed can be arbitrarily set according to the thickness of the thin plate and the number of superposed sheets. Also, by appropriately processing the shape of the end of the thin plate as needed, a pattern of an arbitrary diffraction grating is formed. Also, by shifting the thin plates and stacking them,
It is also possible to easily form a diffraction grating having a curved surface structure.

A thin plate having a thickness on the order of several hundred μm is used for the separation of far-infrared light, but the thickness is not particularly limited, and may be appropriately determined according to the wavelength of light to be separated. Selected.

The invention of this application has the above-mentioned features, and will be described in more detail with reference to examples below.

[0017]

EXAMPLE As shown in FIG. 6, an end portion of a thin plate having a thickness of 500 μm was processed so that a blaze angle was 30 degrees, and 60 processed thin plates were overlapped and fixed by a folder, and spectral analysis was performed. An element was fabricated and an experiment was performed. In the experiment, the orientation of the blazed grating of the manufactured spectroscopic element was set as shown in FIGS. 7A and 7B, and irradiation with far-infrared light was performed while changing the irradiation angle from 0 ° to 90 °. The angle dependence of the device was examined by measuring the light intensity.

FIG. 7 shows the orientation of the blaze grating of the spectral element.
FIG. 8 shows the result of an experiment performed with the setting as shown in FIG. 9A, and FIG. 9 shows the result of the experiment performed with the setting as shown in FIG. 7B. From FIG. 8, in addition to the reflected light appearing near the irradiation angle of 45 degrees, diffracted light is seen near the irradiation angle of 10 degrees. In FIG. 9 in which the direction of the blazed grating is reversed, diffracted light appears near the irradiation angle of 80 degrees (= 90-10 degrees). It was proved to have the function.

[0019]

As described above in detail, according to the invention of this application, a method for manufacturing a spectral element having a blazed grating pattern formed on the order of several hundred μm in an arbitrary shape is provided. According to the method for manufacturing a spectroscopic element of the invention of the present application, it is possible to easily manufacture a spectroscopic element having a complicated shape such as a curved surface, which has been difficult so far, and to contribute to the development of a new optical element. Practical application is expected.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a structure of one embodiment of a spectral element according to the invention of the present application.

FIG. 2 is a schematic diagram showing a structure relating to one mode of the spectral element according to the invention of this application.

FIG. 3 is a schematic diagram showing a structure relating to one embodiment of the spectral element according to the invention of this application.

FIG. 4 is a schematic diagram showing a structure relating to one embodiment of the spectral element according to the invention of this application.

FIG. 5 is a schematic diagram showing a manufacturing procedure for one embodiment of the spectral element according to the invention of this application.

FIG. 6 is a schematic diagram showing a structure of a spectroscopic element manufactured in an example of the present invention.

FIG. 7 is a schematic diagram showing directions of a blazed grating constituting a spectral element in an embodiment of the present invention.

FIG. 8 is a graph showing the results of an experiment performed in an example of the present invention.

FIG. 9 is a graph showing the results of an experiment performed in an example of the present invention.

[Explanation of symbols]

 Reference Signs List 10 thin plate 20 thin plate 30 thin plate 31 folder 40 thin plate 50 thin plate 70 spectral element 71 far-infrared laser 72 scattered light

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hideyuki Otake 13-9-302, Rokunamachi, Okazaki-shi, Aichi F-term (reference) 2G020 AA03 CC03 CC11 2H049 AA07 AA13 AA18 AA31 AA58 AA63

Claims (4)

[Claims] 1. A light-splitting element provided with a diffraction grating for obtaining light of a specific wavelength spectrum, wherein a plurality of thin plates having a thickness on the order of several hundred μm are in contact with adjacent thin plates. A spectroscopic element characterized in that a groove is formed at an end of a thin plate by being fixed in such a state of being overlapped as described above to form a diffraction grating. 2. A spectroscopic element provided with a diffraction grating for obtaining light of a specific wavelength spectrum, wherein a plurality of thin plates having a thickness on the order of several hundred μm are in contact with the surfaces of adjacent thin plates. A spectroscopic element, wherein the thin plates are fixed in such a manner that the thin plates are displaced so that the surface formed by the ends of the thin plates becomes a curved surface. 3. A light-splitting element provided with a diffraction grating for obtaining light of a specific wavelength spectrum, wherein a plurality of thin plates having a thickness of the order of several hundred μm are in contact with adjacent thin plates. The thin plate is periodically shifted so that the surface formed by the end of the thin plate is cut into a curved surface and the blaze angle is formed on the curved surface formed by the end of the thin plate. A spectroscopic element characterized by being fixed by: 4. A far-infrared spectroscopy device comprising the spectroscopic element according to claim 1.