JPH0415529A - Two-dimensional image spectral device and two-dimensional image spectral processor and its method - Google Patents

Abstract

PURPOSE:To obtain the bright and high resolution, and also, to obtain the two-dimensional image in a short time by a simple operation by dispersing a light beam from a first multi-slit, and thereafter, projecting a first multi-slit image by a dispersed light onto a second multi-slit. CONSTITUTION:A zero dispersion spectroscope 100 is constituted of a Czerny- Turner spectroscope of two stages, and consists of one piece of common plane diffraction grating 40, four pieces of spherical concave mirrors 30, 50, 70 and 80, plane mirrors 55, 65 for changing an optical path, a first multi-slit 20 fixed in the vertical surface, and a second multi-slit 60 being rotatable in the horizontal surface. Also, a pair of a movable first lens 10 and a fixed second lens condense a light beam from a light source 5, and obtain a parallel luminous flux of the diameter corresponding to a size of the multi-slit. Also, a plane mirror 85 and a spherical mirror 90 allow the light source 5 to form an image on the photodetecting surface 95, and a chromatic aberration whose elimination is necessary at the time of using a lens is not generated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a secondary optical image spectroscopic device, and more particularly to a secondary optical image spectroscopic device using a multi-slit, a secondary optical image spectroscopic processing device, and a method thereof. .

[Conventional technology]

Regarding conventional two-dimensional image optical amplifiers, see, for example, Spectroscopy Research Vol. 36, No. 3 (1987), pp. 195-202, ``Spatial distribution of light emission intensity in a frame by a two-dimensional image processing spectrometer. A proposal has been made entitled ``Measurement of ``.

This first prior art uses two Zzernitana-type slit spectrometers in series, the first spectrometer extracts a specific wavelength component, and the second spectrometer is placed just above the first spectrometer. It attempts to completely remove the angular dispersion component contained in the selected light component by passing light from the opposite direction. In this prior art, narrow rectangular openings are used for the entrance and exit slits, but the light rays that enter the slits are parallel beams, and most of the light quantity is lost.

At this time, if the slit width is widened, the light energy increases, but the resolution of the spectrometer naturally decreases.

Therefore, it is necessary to use a two-dimensional image optical amplifier (image intensifier 1.1.) that increases the amount of light decreased by the slit, but this is extremely expensive and has a relatively short lifespan. However, for dark objects that could not be amplified sufficiently, the resolution had to be lowered or the observation had to be abandoned.

A similar technique has also been proposed in Japanese Patent Laid-Open No. 139222/1983.

Furthermore, Applied Optics (APPLIE) pioneered the technology of two-dimensional image spectroscopy using multi-slits.
D0PTiC3) Volume 12 (February 1973) No. 28
Page 5 9 Page 288 rspectrometric Tm
ager.

There is Part 2 J.

This second conventional method uses two-dimensional and two-dimensional multi-slits 1 to 1 in the prism spectrometer, with spatial elements of 7 x 9 and color elements of 1.
This is a spectral image forming device that identifies 5 (wavelength resolution number).

This 1: A photoelectric detector is used to detect the inside of f, and 2. Next i[
', Multi-slit +- slides up, down, left and right I, 6
Three types of transmission mask patterns are selected, and the -dimensional multi-slit slides left and right to select 15 types of mask patterns. The total combination of these two mask positions is 63 X
Since i 5 =945 different detection signals are obtained, it is possible to solve the multidimensional simultaneous equations using numerical calculations.

The biggest drawback of this method is that the intensity and spatial distribution of the light source must remain completely unchanged while obtaining 945 detection signals. Even though the power of computers has improved in recent years, it takes a very long time to calculate the inverse matrix of 63 rows and 15 columns, so it is almost impossible to obtain a spectral image in real time. .

In addition, the wavelength resolution of 15 and the spatial resolution of 7×9 could not satisfy the practical performance requirements.

[Problem to be solved by the invention]

The problem with the above conventional techniques is that either an extremely dark two-dimensional spectroscopic device can be obtained, or even bright objects can only be measured at a stationary object, and image reconstruction requires a large amount of calculation time.

The first objective of the present invention is to (1) solve the problems of the prior art and (5) provide a four-dimensional image spectrometer that is bright and has high resolution.

A second object of the present invention is to provide a secondary optical image spectroscopic processing device and its method capable of obtaining two-dimensional optical images in a short time by extremely simple calculations, and thereby The objective is to make real-time measurement also nJ-capable.

In addition, the present invention includes various improvements in its specific device configuration, etc., but the purpose of each will be explained each time.

[Means to solve the problem]

In order to achieve the first object, an optical system comprising at least two multi-slits and a means for receiving a two-dimensional image and guiding light from a light emitting source to a first multi-slit; After dispersing the light from the slits, the first multi-slit image of the dispersed light is projected onto the second multi-slits 1-I-, and the light from the second multi-slits 1-I is used. and an optical system for forming a two-dimensional image of the light source on the light-receiving surface of the two-dimensional image.

In order to achieve the second object, in addition to the above means, the upper memory 1 and the second multi-slit are made to have the same shape,
By creating a first state in which the light-transmitting part and the light-blocking part of the first and second multi-slits optically match, and a second state in which they have an opposite relationship, the above-mentioned first state The light intensity difference between the two-dimensional image of the light-receiving surface and the two-dimensional image of the light-receiving surface in the state of memory 2 is calculated for each point in the two-dimensional image.

Regarding individual means for achieving other objectives,
This will be explained in detail in Examples below.

[Effect]

According to the invention, a first multi-slit image is projected onto a second multi-slit image. At this time, it is assumed that the spectrum I of the incident light is a mixture of wavelengths λ1 and λ2. If the diffraction conditions of the dispersive element, such as a diffraction grating, match the wavelength λ1, and if the two multi-slits have the same shape and the same phase, then all of the light from the λ beam that passes through the first multi-slit will be It will pass through the second multi-slit. Conversely)
In the case of the φ phase, all the light of λ1 is blocked, and the image captured after passing through the second multi-slit has no λ1 component at all.

On the other hand, for light with a wavelength λ2 that does not satisfy the diffraction condition, the first multi-slit image is projected onto the surface of the second multi-slit with a difference in wavelength. As a result, the light passing through the two multi-slits is halved. This means that the two multi-slits are in phase.

Both of the opposite phases are almost equal. If the optical position of this multi-slit is the so-called pupil position, it will affect the amount of light of the entire image captured by a two-dimensional semiconductor camera or the like, but the multi-slit pattern alone or intersecting will not damage the image. Therefore, a bright and high-resolution two-dimensional spectral image can be obtained.

Furthermore, from the fourth-order image taken when the two multi-slits were in phase, No. 14 No. 1. If you subtract the fourth-order iL image pixel by pixel, you get 1. In the screen formed by pixels with a - difference, the part with the wavelength λ] is emphasized, and in the case of other wavelengths, the λ2 component is canceled out. A 7-dimensional image can be obtained. Therefore, a 2-dimensional image at a specific wavelength can be obtained extremely easily and in a short time.

At this time, the opening L of the multi-slit is
One area is approximately to=too times larger, and since the light passes through the entrance and exit sides twice, the amount of light can be considered to be approximately 100 to 10,000 times the square of this value.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG. A surface diffraction grating 40,
Four spherical concave mirrors 30, 50, 70.80, a plane mirror 55.65 for changing the optical path, a first multi-slit 20 fixed in a vertical plane, and a second multi-slit rotatable in a horizontal plane. It consists of 60. A set of a movable first lens 10 and a fixed second lens 15 is used to obtain a diameter of IN t11 corresponding to the size of the multi-slit by transmitting 4 rays of light from a light source 5. The ten-curve mirror 85 and the one-ball mirror 90 form an image of the light source 33 on the light-receiving surface 95, and do not produce chromatic aberration that needs to be removed when using a one-lens lens.

The flat diffraction grating T-40 rotates around the rotation axis 75 in accordance with the wavelength of the spectral spectrum, and can continuously change the diffraction grating 1. At this time, since the focal length of the 1st lens 10 and 1.5 corresponding to the selected wavelength is known in advance, the 1st lens 10 is moved to the optical axis 6 according to the wavelength scanning device of the spectrometer. By moving in the direction 12, the light beam 1-6 passing through the second lens 3-5 can always be kept parallel.

The first multi-slit 20 placed in the parallel light beam is placed at the front focal point of the spherical concave mirror 30 via the plane mirror 25, and is diffracted according to the wavelength by the diffraction grating 40 placed at the rear focal point of the spherical concave mirror 30. Nine.

At this time, the image of the light source 5 will be formed on the virtual plane of the diffraction grating 40.

On the other hand, since the spherical concave mirror 50 is arranged so that its front focal point is located at the diffraction grating 40 and its rear focal point is located at the second multi-slit 60, the diffracted light 4]- is reflected upward by the plane mirror 55 and parallel A luminous flux 56 is obtained. Therefore, in this case,
The two multi-slits are located at optically conjugate points, and the first
The image of the multi-slit 20 is the image of the second multi-slit 6
The image will be formed on the 0 plane.

Here, the second multi-slit 60 can be rotated by 90° in the direction 62 within its plane, and the positions of the light-transmitting portion and the light-blocking portion of the slit pattern are switched each time the second multi-slit 60 rotates by 90°. That is, the phase is reversed. As a result, the light flux that has passed through the second multi-slit 60 contains wavelength components that satisfy the diffraction conditions in an amount twice as much as other wavelength components, or does not contain them at all.

The parallel light passing through the second multi-slit 60 is reflected by the plane mirror 6
Turn around at 5 and head toward the spherical concave mirror 70. Two spherical concave mirrors 70
．． 80 is at the same position in plan as the spherical concave mirror 50.30 located below it, and the light beam that is incident on the upper part of the plane diffraction grating 40 and is dispersed due to diffraction becomes a light ray 76 without a dispersion component and is reflected by the spherical concave mirror 80. incident on . Here, it becomes a parallel light beam, enters the plane mirror 85, is reflected by the spherical mirror 90f, enters the light receiving surface 95 of a two-dimensional semiconductor camera or two-dimensional image optical amplifier, and is taken into an image processing device (not shown). It turns out.

FIG. 2 shows a rectangular hyperbolic multi-slit pattern with four quadrants. Figures (a) and (Y) are antisymmetrical with respect to the center y-axis, that is, the light-transmitting part and the light-blocking part are il 13.

If you rotate figure (a) in any direction by 90'', you will see figure (b).
) is found to be -M. FIG. 2 shows a multi-slit image in a reverse phase state.

FIG. 3 shows a mechanism for rotating the rectangular hyperbolic multi-slit by 90 degrees, in which when the gear 62 driven by the step motor 110 rotates 90' around the rotation axis 1] The multi-slit 60 fixed inside the gear 61- supported by the gear 61- is rotated by 90 degrees. Of course,
The pulse motor 110 must be supplied with a pulse train corresponding to 90'' rotations.

To further explain the above operation using FIGS. 4 and 5, the right-angled hyperbolic multi-slit in FIG.
'', the appearance of the first multi-slit aperture imaged on the second multi-slit aperture is as shown in FIG. 4 (1).

If the radius of this open circle is r, then the distance X between the X-axis and the X-axis changes due to the dispersion of the plane diffraction grating, corresponding to the wavelength difference.

That is, the efficiency curve 3 is the transmission efficiency (η)]- shown in FIG. 4(a) expressed as a function of the dispersion distance (x).

When the wavelength difference is O, the inner aperture transmits -1 (100%), but when the dispersion distance /dx:
n m/mn).

From now on, the wavelength range that passes through the multi-slit is extremely wide (low resolution) compared to the single-slit I-.
I understand.

Two multi-slits are used to improve the resolution of this low-resolution state to the level of instant slit I, and their operation is shown in FIG.

Now, considering a rectangular hyperbolic four-quadrant pattern, the ratio of light-transmitting parts to light-blocking parts is 0.5:0.5 over the entire area.

The peak 7 of the light transmission efficiency when the two Mardiss I. (b)).

However, this is for the wavelength difference O, that is, the light component that matches the wavelength to be separated, and the amount of light at other wavelengths is
It attenuates symmetrically around the wavelength difference of 0.

That is, the curve 4 of ]/4 of the efficiency curve 3 in FIG. 4(a) is.

Since the parallel light flux passes through the second multi-slit, a change in the amount of light at one point of the multi-slit only changes the entire light-receiving surface of a two-dimensional camera or the like. vice versa,
The total amount of light passing through the multi-slit surface is
This corresponds to the amount of light at a point. Therefore, the in-phase condition (
From the image data obtained with efficiency η0), if we perform a difference operation on the negative phase condition (efficiency η) corresponding to each pixel (imaging point), the obtained overall efficiency (η0 - η) is shown in Figure 5 ( It has a sharp peak like curve 9 in c). Since monochromaticity is guaranteed for each pixel, it can be said that the image itself, which is a two-dimensional set of pixels, is monochromatic.

This difference calculation may be performed using an analog difference between video signals, but it is preferable to rely on digital image processing, which has developed rapidly in recent years.In this case, it is easier to process if one image data is stored digitally. be.

The width of the peak 9 corresponds to the fineness of the rectangular hyperbola pattern used for the multi-slit. The width at the end of the inner opening of the transparent portion in contact with the X-axis of the first quadrant in FIG. 2(a) can be said to be the half-width of peak 9. That is, if the in-phase images shift by one stripe, the transmission efficiency will drop to 50% of that of perfect matching. Of course, it is meaningless to make a multi-slit pattern so thin that it cannot be imaged, and there is a limit to how fine it can be without losing linearity due to diffraction phenomena.

Next, applications and modifications of the present invention will be described below.

FIG. 6 shows an optical system that creates two states, in-phase and anti-phase, using a rotating plane mirror (chopper) 120 for optical path switching without rotating the second multi-slit 60. Incident ray 5
1 is reflected upward by a plane mirror 55, passes through a notch 125 of a chopper 120 that rotates around a rotation axis 122, and passes through a multi-slit 60 that is in phase with a first multi-slit (not shown). , plane reflector 145. chopper 12
After passing through a 0° flat reflecting mirror 65, a light ray 66 is directed toward a spherical concave sphere (not shown). When the reflecting surface of the chopper 120 comes to the opposite position (dotted line), the light passes through the third multi-slit]-30 fixed in the opposite phase and is reflected by the plane reflecting mirror 135.65 to become a light beam 66. At this time, the chopper 120 is rotated to the position of the reflective surface 125, and the third multi-slinter 8
1304 There is no blocking of the light flux that has passed, and the number of reflections is always the same.

FIG. 7 shows a specific example of the chopper 120, in which (a) shows one blade, and (b) shows two blades.

In any case, since the method shown in FIG. 6 allows the phase state to be switched in a short time, it is also possible to obtain images that change in real time by using two consecutive screens.

FIG. 8 shows an example using an Evert type spectrometer using - large spherical mirrors], 40 &, and the same symbols as before indicate the same members.

FIG. 9 shows the reflection angle 33 of the spherical concave mirror 30 and the spherical concave mirror 50.
．． This is an example using a so-called asymmetric Zernitana spectrometer with different 53. By making it asymmetric, the spherical mirror Cam
The aberration can be selected to be the minimum.

FIG. 10 shows a Cassegrain optical system using a large holed concave mirror 150 and a small convex mirror 155 as optical means for inputting a parallel beam of light into the first multi-slit of the spectrometer. The light beam 6 from the light source 5 is condensed by the concave mirror 1-50, becomes a parallel light beam 16 by the convex mirror 155, and enters the first multi-slit 20. As a result, chromatic aberration unlike when using a lens does not occur, and there is no need to automatically correct the focal length. Further, it is possible to introduce light source light having an extremely wide wavelength range of ultraviolet, visible and infrared.

FIG. 1-1 is an explanatory diagram of image processing, and the in-phase image 1
60 and an image 170 of opposite phase to obtain a difference image 80, it is shown that pixel 184 can be found by intensity calculation between corresponding pixels 164° and 174.

For this processing, it is necessary to store at least the image 160 in a digital memory, and if the difference calculation is to be performed at a different time, the image 170 must also be stored. Particularly when image data is to be captured at a high speed, a pair of two circulated screens must be stored in a digital memory.

FIG. 12 shows one method for manufacturing multi-slits. For example, when using a rectangular hyperbolic pattern, y=k
- A mathematical formula i/x and a program 200 that calculates this and alternately colors areas are given to a small computer with a monitor 210, and the results of the execution are displayed on the monitor screen. This screen is then recorded on a black and white hard copy 220, and this copy 220 is taken on photographic film 230. Photolithography 240 is performed using this photographic film 230, an exposure illumination light source (not shown), and a thin metal plate coated with photoresist.

As a result, even thin patterns with relatively complex shapes can be realized and utilized as multi-slits.

Further, in the above embodiments, a plane diffraction grating is used as the dispersion element, but the dispersion element is not limited to this, and for example, a concave diffraction grating, a prism, etc. can also be used. Further, although a quadrilateral rectangular hyperbolic pattern is used as an example of multi-slits, the present invention is not limited to these and can be modified as appropriate.

〔Effect of the invention〕

According to the present invention, two-dimensional spectroscopy with high efficiency and high resolution can be realized, so even a dark light source can be observed without sacrificing wavelength resolution.

Furthermore, a two-dimensional image of the light source at any wavelength can be obtained in a short time with simple calculations. Therefore, real-time spectroscopic measurement of two-dimensional images is also possible.

Furthermore, since a large amount of numerical calculations such as solving multidimensional simultaneous equations is not performed, the number of pixels can be increased, and therefore, the spatial resolution can also be extremely high. For example, it is not a hard limit to limit the spatial resolution to about 100×, OO, and the maximum wavelength resolution to OO.

[Brief Description of the Drawings] Fig. 1 is a perspective view of an embodiment of a two-dimensional image spectrometer according to the present invention, Fig. 2 is a diagram of an embodiment of a multi-slit system, and Fig. 3 is a diagram of a multi-slit rotation mechanism. Explanatory drawings, Figures 4 and 5
The figures are a characteristic diagram for explaining the action of the embodiment shown in Fig. 1, and Fig. 6.
The figure is an optical system diagram in another embodiment of the present invention, FIG. 7 is an explanatory diagram of a chopper used in the same optical system, and FIGS.
The figures show the spectrometer system; Figure 8 is the Ebert type, Figure 9 is the asymmetric Siernitana type optical system diagram, Figure 10 is the Cassegrain type introduction optical system diagram, Figure 11 is the image processing diagram, and Figure 1
Figure 2 is a flowchart showing an example of a method for manufacturing multi-slits. 10.15...Lens, 20.60.Multi-slit, 25,55,65.85...Plane mirror, 30°50.
70.80... Spherical concave mirror, 40... Plane diffraction grating, 9
0... Spherical concave mirror, 100... Zero dispersion spectrometer, 110
・Pulse motor, 120... Optical path switching rotating mirror, Fig. (a) (b) Fig. Fig. Dispersion distance (rl Fig. η0 1.5529 (10) Fig. Q Fig.

Claims (1)

[Claims] 1. A device for dispersing a two-dimensional image from a light emitting source, comprising: a first optical system that guides light from the light emitting source to a first multi-slit; a second optical system that disperses light and projects the first multi-slit image after the dispersion onto a second multi-slit; and a second optical system that disperses the light and projects the first multi-slit image onto a second multi-slit; A two-dimensional image spectrometer comprising: a third optical system that forms a dimensional image on a light-receiving surface. 2. In claim 1, the first and second multi-slits have the same shape, and a first state in which the light-transmitting part and the light-blocking part of the first and second multi-slits are optically coincident and completely A two-dimensional image spectroscopy device comprising means for switching between an opposite second state. 3. In a device that spectrally spectra a two-dimensional image from a light emitting source to obtain a two-dimensional image of any wavelength of the light emitting source, first and second multi-slits having the same shape and light from the light emitting source are provided. a first optical system that guides the light to the first multi-slit, and disperses the light from the first multi-slit, and projects the first multi-slit image after the dispersion onto the second multi-slit. a second optical system; a third optical system that images the light from the second multi-slit onto a two-dimensional light-receiving surface; and a light-transmitting part and a light-blocking part of the first and second multi-slits. a two-dimensional image of the light-receiving surface in the first state and a two-dimensional image of the light-receiving surface in the second state; A two-dimensional image spectroscopic processing device comprising means for determining a light intensity difference between a two-dimensional image and a two-dimensional image at each point in the two-dimensional image. 4. The two-dimensional image spectroscopic processing device according to claim 3, wherein the first and second multi-slits are formed in a rectangular hyperbolic pattern with four quadrants. 5. In claim 3, the light receiving surface is constituted by a semiconductor camera or a large number of light receiving elements that detect the light intensity at each point of the two-dimensional image, and the light intensity at each point of the two-dimensional image is digitally stored. A two-dimensional image spectroscopic processing apparatus, comprising means for calculating the difference between the digital value of the storage means in the first state and the digital value in the second state. 6. In a method of spectrally dispersing a two-dimensional image from a light emitting source to obtain a two-dimensional image of an arbitrary wavelength of the light emitting source, first and second multi-slits having the same shape and light from the light emitting source are provided. an optical system that projects the light from the first multi-slit onto the first multi-slit and projects the first multi-slit image onto the second multi-slit through a dispersion element, A two-dimensional image from the second multi-slit in the optical system is stored in a first state in which the light-transmitting part and the light-blocking part of the first and second multi-slits match, and A two-dimensional image from the second multi-slit in the optical system is obtained in a second state in which the light-transmitting part and the light-blocking part of the slit are optically opposite, and the two-dimensional image is combined with the stored two-dimensional image. A two-dimensional image spectroscopic processing method, comprising calculating a two-dimensional image of the light emitting source at an arbitrary wavelength from the light intensity difference at each point. 7. A first means for collimating the light from the light emitting source, a second means for focusing the collimated light from the means on a plane diffraction grating position, and collimating the light diffracted by the plane diffraction grating. a first multi-slit is arranged at the front focal position of the second means, a second multi-slit is arranged at the rear focal position of the third means, A two-dimensional image spectrometer, further comprising a fourth means for forming an image of the light from the second multi-slit on a two-dimensional light receiving surface. 8. In claim 7, the second multi-slit is:
A first state in which the light-transmitting part and the light-blocking part are located at the optical conjugate point of the first multi-slit and have the same shape, and the light-transmitting part and the light-blocking part optically match with respect to the first multi-slit, and a completely opposite state. A two-dimensional image spectrometer capable of taking a second two-phase state. 9. In claim 8, the first and second multi-slits have a rectangular hyperbolic pattern with four quadrants, and the transparent portions and the light-blocking portions are alternately arranged and have opposite phases between adjacent quadrants. By rotating the first or second multi-slit by 90 degrees within its plane, it is possible to realize a first state in which they are optically coincident with each other and a second state that is completely opposite to each other. Dimensional image spectrometer. 10. Claim 7, further comprising a third multi-slit, the first or second multi-slit being optically switchable with the third multi-slit, and the third multi-slit being optically switchable with the third multi-slit.
A two-dimensional image spectrometer, wherein the multi-slit is optically opposite in phase to the first and second multi-slits. 11. In claim 10, the first to third multi-slits have a rectangular hyperbolic pattern with four quadrants, and the transparent parts and the light-blocking parts are arranged alternately and have opposite phases between adjacent quadrants. The second multi-slit and the third multi-slit are relatively rotated by 90 degrees within the plane of the two-dimensional image spectrometer. 12. The two-dimensional image spectrometer according to claim 9, wherein the first or second multi-slit in-plane orthogonal rotation mechanism comprises a pulse motor and a constant pulse number generation circuit for driving the pulse motor. 13. In claim 7, the second means for forming a light source image at the position of the plane diffraction grating and the third means for collimating the diffracted light from the plane diffraction grating are spherical concave mirrors. Two-dimensional image spectrometer. 14. In claim 7, the third
between the means and the fourth means for forming an image on the light receiving surface,
By comprising a fifth means corresponding to the second means and a sixth means corresponding to the third means, and disposing the plane diffraction grating between the fifth and sixth means. . A secondary optical image spectrometer configured such that angular dispersion contained in the light from the third means is removed after the sixth means. 15. Claim 14, wherein one common plane diffraction grating is provided, the second and third means and the fifth and sixth means are composed of spherical concave mirrors having the same focal length; Fifth
It has two plane mirrors for changing the optical path between the means, and the first multi-slit is located in front of the second means at the focal point, and the second multi-slit is provided between the two plane mirrors. A secondary optical image spectrometer equipped with a two-stage stacked spectrometer with multi-slits. 16. In claim 7, a first angle formed by the second means for forming the light source image and the center of the plane diffraction grating;
A secondary optical image spectrometer comprising an asymmetric Zzerny-Turner type in which a second angle between the third means for collimating the diffracted light and the center of the plane diffraction grating is different. 17. In claim 7, the first means for collimating the light from the light emitting source is one or more condensing lenses, and at least one of the lenses is configured to collimate light from a subsequent spectrometer. A secondary optical image spectrometer configured to move linearly along the optical axis of the lens in response to wavelength scanning rotation of the grating to correct changes in focal length due to the wavelength of the lens. 18. In claim 7, the first means for converting the light from the light emitting source into a light beam is a Cassegrain type condenser mirror comprising one concave mirror having a small opening in the center and one small convex mirror or plane mirror. A secondary optical image spectrometer. 19. A secondary optical image spectrometer according to claim 7, wherein the fourth means for forming a light source image on the light-receiving surface of the parallel diffracted light comprises one plane mirror and one spherical concave mirror. 20. A multi-slit manufacturing method with a right-angled hyperbolic pattern includes a built-in program containing a mathematical formula representing a right-angled hyperbola, a hard copy of the right-angled hyperbolic pattern on a CRT screen created by the program, and the copied pattern is printed on a metal plate. A method for manufacturing a multi-slit rectangular hyperbolic pattern characterized by manufacturing by optical etching.