JP2000337961A - Double monochromator and spectrophotometer using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double monochromator for which the wavelength and width of the emitted light can be controlled easily and which has high wavelength scanning accuracy. SOLUTION: The inlet slit 1 of the first monochromator 103 of a double monochromator is arranged in parallel with the outlet slit 14 of the second monochromator 104 so that the center lines of the slits 1 and 14 may form a straight line and a pair of blades constituting the inlet slit 1 is coupled with a pair of blades constituting the outlet slit 14 to constitute a first coupled slit 401. First and second intermediate slits 6 and 9 are arranged in parallel with each other so that their center lines may form a straight line and a pair of blades constituting the first intermediate slit 6 is coupled with a pair of blades constituting the second intermediate slit 9 to constitute a second coupled slit 402. First and second scattering sections 4 and 11 are coupled with each other so that their center axes may form a straight line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monochromator for converting light into monochromatic light having a desired wavelength, and a spectrometer using the monochromator.

[0002]

2. Description of the Related Art In a spectrometer using a monochromator, a double monochromator is often used especially when it is necessary to reduce stray light. As shown in FIG. 7, a double monochromator generally connects two monochromators 701 and 702 of the same design simply via an intermediate slit 703 to form a first monochromator 70.
In this configuration, the exit slit 1 and the entrance slit of the second monochromator 702 are used as a common intermediate slit 703. Therefore, light emitted from the first monochromator 701 further enters the second monochromator 702 and is further dispersed, and only desired monochromatic light is emitted from the exit slit 715. Thus, most of the stray light included in the monochromatic light emitted from the first monochromator 701 can be dispersed and removed by the second monochromator 702. In the configuration of FIG. 7, the first and second
The optical systems inside the monochromators 701 and 702 each include a plane mirror 705, 710 and a collimator mirror 70.
6, 711, gratings 707, 712, focusing mirrors 708, 713, plane mirrors 709, 71
4 is a configuration of a Czerny-Turner type monochromator in which No. 4 are arranged in order.

[0003] A double monochromator (U-1000 manufactured by Joban Ivon Co.) as shown in FIG. 8 is also known. It comprises a first monochromator 801, a relay optical system 803, and a second monochromator 802, and the relay optical system 803 is formed by a concave
The image of the first exit slit 804 is formed on the entrance slit 805 of the second monochromator. In the configuration of FIG. 8, the grating of the first monochromator 801 and the second
The grating of the monochromator 802 is mounted on the same shaft. Inlet slit 806, outlet slit 8
The operation of the four slits including 07 is independent of each other.

[0004] There are two types of double monochromator, an additive dispersion type and a zero dispersion type. The additive dispersion type is configured so that the chromatic dispersions of two monochromators are additive. Are configured such that chromatic dispersions cancel each other.

[0005]

The conventional double monochromators of FIGS. 7 and 8 have the following problems. In the double monochromator, the first monochromator and the second monochromator must pass the same wavelength, so that it is necessary to accurately synchronize the wavelength settings of the first and second monochromators. However, in the configuration of FIG. 7, in order to synchronize the wavelengths of the two monochromators 701 and 702, gratings 707 and 712, which are dispersive elements, are used.
Must be set to exactly the same angle,
In the above configuration, the gratings 707 and 712 are set apart from each other. Therefore, it is necessary to provide a special wavelength synchronization mechanism for synchronizing and rotating these angles. Such a mechanism has a complicated structure and causes an increase in cost and an unstable operation.

In the configuration shown in FIG. 8, since two gratings of two systems of monochromators 801 and 802 are mounted on the same shaft, the monochromator 8
01, 802, while the wavelength synchronization is automatically and accurately maintained, the four slits 804, 805, 806, 807
Must be controlled independently, and the operation becomes complicated. In addition, since the relay optical system 803 is configured as a single concave mirror except a flat mirror, for example,
Due to its performance limitations, the incident NA of the spectrometer system could not be made too large. Furthermore, the relay optical system 803 has a limit in optical aberration, which is a limiting factor such as wavelength resolution.

SUMMARY OF THE INVENTION An object of the present invention is to provide a double monochromator which can easily control the wavelength width of emitted light and has high wavelength scanning accuracy.

[0008]

According to the present invention, there is provided the following double monochromator.

That is, a first monochromator optical system,
A second monochromator optical system, and a relay optical system that causes light emitted from the first monochromator optical system to enter the second monochromator optical system, wherein the first monochromator optical system has an entrance slit; A first dispersion unit for dispersing the light incident from the entrance slit, and a first intermediate slit for passing the light dispersed by the first dispersion unit and emitting the light, and the second monochromator optical system includes: , A second intermediate slit, a second dispersion section for dispersing the light incident from the second intermediate slit, and an exit slit for passing the light dispersed by the second dispersion section and emitting the light, and the entrance The slit and the exit slit are arranged so that the center line of each slit width is straight, and a pair of blades constituting the entrance slit are a pair of blades constituting the exit slit. Consolidated is and, the first intermediate slit and the second intermediate slit is disposed center line of the respective slit width arranged so that the straight line, the first
A pair of blades forming the intermediate slit is connected to a pair of blades forming the second intermediate slit, and the first dispersing portion and the second dispersing portion are connected such that their central axes are aligned. A double monochromator.

The relay optical system described above can be an Offner type projection optical system for projecting the image of the first intermediate slit onto the second intermediate slit at the same magnification.

[0011] The first connecting slit may have a drive source for opening and closing the pair of blades connected to each other.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings.

First, a double monochromator according to a first embodiment of the present invention will be described with reference to FIGS. 1 (a), 1 (b), 4 and the like.

The double monochromator of the first embodiment has a monochromator optical system 101, a relay optical system 102, and a control unit 130 as shown in FIGS. 1 (a) and 1 (b). Monochromator optical system 101
Are mirrors 3, 5, 10, and 12 and a connection slit 401,
402, a dispersive element 501, and a connecting mirror 110 are included.
The relay optical system 102 includes a concave spherical mirror 7 and a convex spherical mirror 8.

The connecting slit 401 is provided with the blade 4 of the slit 1.
4A and 4B, and the blades 405 and 406 of the slit 14 are connected by connecting portions 411 and 412 as shown in FIG. Slit 1 of connection slit 401 and slit 1
4 is set to a predetermined length 2t.
A drive source (not shown) is connected to the connection portions 411 and 412.
The slit width (blade interval) is adjusted by opening and closing in the arrow direction of (a). Thus, the connection slit 401
Since the two slits 1 and the blades of the slit 14 are connected and opened and closed, the center line 4 in the slit width direction
15 is always kept in a straight line. In addition, slits 1 and 14
Blades 403 to 406 are single blades, and are arranged such that the flat surface faces the light incident side. Slit 1
Denotes an entrance slit, and the slit 14 functions as an exit slit. The slit height of the slits 1 and 14 may be variable. In this case, the slit heights of the two slits 1 and 14 are set to be the same.

The connection slit 402 is also connected to the connection slit 40.
1 and has a slit 6 as shown in FIG.
And the blades 407, 408 of the slit 9 and the blades 409, 410 of the slit 9 are connected by connecting portions 413, 414. By a driving source (not shown), the connecting tool 41 is moved in the direction of the arrow in FIG.
3, 414 are opened and closed to adjust the slit width. The center line 416 in the slit width direction is always kept straight. The interval between the slit 6 and the slit 9 of the connecting slit 402 is also set to a predetermined length 2t. Each of the slits 6 and 9 functions as an intermediate slit. The slit heights of the intermediate slits 6 and 9 are set to values that do not become smaller than the slit heights of the slits 1 and 14.

The dispersion element 501 has a single plane diffraction grating 511 that is long in the direction of the scribe line as shown in FIG. 5, and the diffraction grating portions at both ends are used as the dispersion unit 4 and the dispersion unit 11, respectively.
The distance between the dispersing section 4 and the dispersing section 11 is determined by the connection slit 4
2t, which is the same as the interval between the slits 1 and 14 of FIG. A rotation drive unit 512 is attached to the plane diffraction grating 511. The rotation drive unit 512 rotates the plane diffraction grating 511 about the center axis A of the diffraction grating surface of the plane diffraction grating 511 to select a wavelength. In the present embodiment, the number of grooves of the plane diffraction grating 511 is 1200 / mm,
11 is 60 mm square.

The connecting mirror 110 is a rectangular flat mirror, and both end portions are used as the bending mirror 2 and the bending mirror 13 for changing the direction of the light beam. The distance between the mirror 2 and the mirror 13 is 2t described above.

The mirrors 3 and 10 are collimator mirrors, and the mirrors 5 and 12 are focusing mirrors.
In the present embodiment, mirrors 3, 5, 10, and 12
In each case, an off-axis parabolic mirror having the same shape and a focal length of 300 mm is used.

Connection slits 401 and 402, dispersion element 5
01, connecting mirror 110, mirrors 3, 5, 10, 12
Are arranged as shown in FIGS. 1A and 1B and FIG. That is, on the optical axis 120, the slit 1 on the lower side of the connecting slit 401, the mirror 2 and the mirror 3 on the lower side of the connecting mirror 110, the dispersing part 4 on the lower side of the dispersive element 501, the mirror 5, and the lower part of the connecting slit 402 Side slit 6 is arranged. In addition, on the optical axis 121 parallel to the optical axis 120, the slit 14 above the connecting slit 401 and the connecting mirror 11
The mirror 13 and the mirror 12 above the zero, the dispersion part 11 above the dispersion element 501, the mirror 10, and the slit 9 above the connection slit 402 are arranged.

The slit 1, mirror 2, mirror 3, dispersion unit 4, mirror 5, and slit 6 located on the optical axis 120 are:
The first monochromator 103 is configured. On the other hand, the optical axis 12
1, a slit 9, a mirror 10, a dispersion unit 11,
The mirror 12, the mirror 13, and the slit 14 constitute a second monochromator 104. First monochromator 10
3, the second monochromator 104 includes a dispersion unit 4,
Reference numeral 11 denotes a Czerny-Turner type monochromator using a plane diffraction grating.

The interval between the optical axis 120 and the optical axis 121 is 2t described above. The distance between the optical components in FIG. 2 is L1 = L2 = L4 = 300 mm, L3 = 140,
L5 = 160 mm.

On the other hand, the concave spherical mirror 7 and the convex spherical mirror 8 of the relay optical system 102 are arranged on the optical axis 122 as shown in FIGS. 1 (a), 1 (b) and 3. The optical axis 122 is the optical axis 120, 121 at the time of passing through the connection slit 402.
The optical axis is located just in the middle of and is parallel to these.
The distance between the optical axis 122 and the optical axes 120 and 121 is t
It is. With this arrangement, the first monochromator 103 and the relay optical system 102 and the relay optical system 102 and the second monochromator 104 are telecentrically coupled with the coupling slit 401 interposed therebetween. The concave spherical mirror 7 and the convex spherical mirror 8 constitute a so-called Offner type projection optical system, and form an image of light emitted from the lower slit 6 of the connecting slit 402 into the upper slit 9 at exactly 1 × magnification. Image.

In FIG. 3, the length L10 = 1000
mm, L11 = 497.48 mm, t = 100 mm, radius of curvature R1 = 502.52 mm, and R2 = 1000 mm.

The driving sources of the coupling slits 401 and 402 of the monochromator optical system 101 and the dispersion element 50
1 is a control unit 13
0, and adjusts the slit width and adjusts the angle of the diffraction grating 511 according to instructions from the control unit 130.

Next, the operation of the double monochromator of this embodiment will be described. Control unit 1
Reference numeral 30 designates a slit width corresponding to a desired wavelength resolution to a driving source of the connection slit 401. Thereby, the slit widths of the entrance slit 1 and the exit slit 14 are set to the same designated slit width. The control unit 130 also instructs the driving source of the connecting slit 401 to the slit width, and sets the slit widths of the intermediate slits 6 and 9 to the same slit width. Control unit 1
Reference numeral 30 denotes a dispersive element that adjusts an inclination angle according to a desired wavelength range.
An instruction is given to one rotation drive source. Thereby, the dispersion element 50
1 is set to a desired angle.

In this state, when light enters from the entrance slit 1 below the connecting slit 401,
The light passes through the optical components of the first monochromator 103 in order and undergoes a spectral action. Specifically, the light incident from the entrance slit 1 is reflected toward the collimating mirror 3 by the mirror 2 below the coupling mirror 110. The collimating mirror 3 collimates the light and reflects the light toward the dispersion section 4 below the dispersion element 501. The dispersing unit 4 diffracts the irradiated light, and the diffracted light is condensed by the focusing mirror 5 and forms an image on the intermediate slit 6 below the connecting slit 402. Of the imaged light, only light having a wavelength width corresponding to the slit width of the slit 6 passes through the slit 6.

The light emitted from the slit 6 is reflected by the concave spherical mirror 7 of the relay optical system 102, and is reflected by the convex spherical mirror 8
Is reflected again by the concave spherical mirror 7 and forms an image at the same magnification on the intermediate slit 9 above the connecting slit 402 of the second monochromator. Then, the light travels through the optical component of the second monochromator in an optical path opposite to that of the first monochromator, and further undergoes a spectral action. Specifically, the light that has passed through the intermediate slit 9 is collimated by the collimating mirror 10 and reflected toward the dispersion section 11 above the dispersion element 501. The dispersion unit 11 diffracts the irradiated light, and the diffracted light is condensed by the focusing mirror 12, the optical axis is turned back by the mirror 13 above the coupling mirror 110, and the exit above the coupling slit 401 is exited. An image is formed on the slit 14, and only light having a wavelength width corresponding to the slit width of the exit slit 11 is emitted from the exit slit 11.

Since the second monochromator 104 has the same configuration as the first monochromator 101 and the optical path is reversed, the light emitted from the exit slit 14 has the center wavelength and the desired wavelength width at the desired wavelength and wavelength. It becomes light of width. This light is almost monochromatic at the stage when it passes through the intermediate slit 6 of the first monochromator 103. However, at this stage, stray light from the first monochromator 103 is still included. Since the stray light component generated by the first monochromator 103 undergoes a spectral action by the second monochromator 104 and forms an image other than the exit slit 14, the light emitted from the exit slit 14 has the stray light component removed.
It becomes monochromatic light of very high purity.

When the light of the set wavelength is emitted from the exit slit 14, the wavelength dispersion is twice as high as that when the first monochromator 103 or the second monochromator 104 is used alone. A more detailed explanation is as follows. First, the relay optical system 102 projects the image of the intermediate slit 6 onto the intermediate slit 9 at a magnification of 1 ×.
Naturally, the absolute value of the inverse linear dispersion value is also equal in each case. The direction of the chromatic dispersion is projected onto the second monochromator 104 such that the chromatic dispersion becomes additive. That is, when the light is incident on the second monochromator 104, it already has the chromatic dispersion of the first monochromator 103, and by passing through the second monochromator 104, the same amount of chromatic dispersion is further added. As a result, chromatic dispersion that is exactly twice that of a single monochromator can be obtained.

FIG. 6 shows a spot diagram at the exit slit 14 of the double monochromator of the present embodiment. However, the diffraction order in the dispersion element 501 is the first order, and the center wavelength is 500 nm. Excellent imaging performance is achieved over the entire slit height of 10 mm. As can be seen from this spot diagram, the double monochromator of the present embodiment not only has aberrations corrected in the wavelength dispersion direction but also achieves substantially the same imaging performance in the spatial direction at the same time. It is a feature.

Also, in the double monochromator of the present embodiment, since the inverse linear dispersion values at the entrance slit 1 and the exit slit 14 are respectively equal, the widths of the entrance slit 1 and the exit slit 14 corresponding to a certain wavelength width Δλ are mutually different. Must be set equal. In the double monochromator of the present embodiment, the connection slit 401 connecting the blade of the entrance slit 1 and the blade of the exit slit 14 is used, so that the entrance slit 1 and the exit slit 14 always have the same slit width. And operation is easy.

Further, when scanning the wavelength to be emitted, the double monochromator of the present embodiment uses the dispersive element 501 using both end portions of one diffraction grating as the dispersing portions 4 and 11, so that the wavelength The rotation axis A to be rotated for scanning coincides with the dispersion units 4 and 11. Therefore, by rotating the diffraction grating 511 of the dispersion element 501 about the rotation axis A, the dispersion units 4 and 11 can always be rotated at the same angle. Accordingly, the set wavelengths of the first monochromator 103 and the second monochromator 104 can always be kept equal by an easy operation.

Further, in the double monochromator of the present embodiment, the slits 6 and 9 are always used because the connecting slits 402 with blades are connected as the intermediate slits 6 and 9.
Can be kept straight. In addition, the slit width of the intermediate slits 6 and 9 can be changed to a certain wavelength width Δ by an easy operation.
It can be set to an equal slit width corresponding to λ. Therefore, the center wavelength and the wavelength width can be maintained by forming the slit image of the slit 6 on the slit 9 at the same magnification by the relay optical system. In the present embodiment, a driving source is attached to the connecting slit 402 and the slit widths of the intermediate slits 6 and 9 are variable. However, the purpose of the intermediate slits 6 and 9 is to remove stray light. Therefore, the width does not necessarily have to be variable, and may be fixed to a certain width.

In the configuration of this embodiment, off-axis parabolic mirrors are used as the collimator mirrors 3 and 10 and the focusing mirrors 5 and 12 of the first and second monochromators 103 and 104. Is no aberration. The relay optical system 102 has an extremely small aberration by using an Offner type optical system.

As described above, according to the first embodiment, it is possible not only to achieve excellent low-stray light performance as with the double monochromator according to the prior art, but also to achieve the
The opening and closing of the opening slit 14 can be easily realized by the connection of the opening slit 14 and the same slit width can be always maintained, so that the wavelength width of the emitted light can be easily and accurately controlled. The same applies to the intermediate slits 6 and 9. Also,
Since the two dispersion units 4 and 11 can be rotated integrally, the wavelength scanning accuracy can be kept high.

Furthermore, the configuration of the first embodiment achieves excellent imaging performance not available in the conventional double monochromator, particularly excellent imaging performance not only in the wavelength dispersion direction but also in the spatial direction. ing. Therefore, when spectroscopically measuring the object to be measured, the present invention can also exert its power in multipoint spectroscopic measurement that utilizes the spatial resolution.

In the present embodiment, the plane diffraction grating 511 is used as the dispersion element 501, but other dispersion elements such as a concave diffraction grating and a prism can be used. Further, in the present embodiment, the connected mirror 110 in which the mirrors 2 and 13 are integrally connected is used.
Can be individual mirrors.

Next, a spectrophotometer using the double monochromator of the first embodiment will be described as a second embodiment.

The spectrophotometer of the second embodiment is shown in FIG.
As shown in FIG. 10, a light source unit 901 having a built-in light source for spectrometry is provided. The light source unit 901 includes a plurality of light sources according to a wavelength range necessary for measurement and the like, and a switching mirror for switching these light sources.

Next to the light source unit 901, there is a sample chamber 90.
2 is disposed, and light emitted from the light source unit 901 enters the sample chamber 902. A holder for holding the measurement sample is provided in the sample chamber 902, and an optical path for irradiating the measurement sample with light is provided. The sample chamber 901 is also provided with an optical path for reference, which allows the sample to pass through without irradiating the sample with light. The selection of the optical path is performed by a switching mirror.

A chopper unit 903 is provided adjacent to the sample chamber 902 so that light emitted from the sample chamber 902 can be chopped. Next to the chopper unit 903 is a filter unit 90
And a plurality of filters for cutting high-order light of the diffraction grating. The filter can be selected according to the wavelength.

Next to the filter unit 904, the first
The double monochromator of the embodiment is installed, and is positioned so that light from the filter unit 904 enters the entrance slit 1 of the connection slit 401. The incident light travels in the order of the first monochromator 103, the relay optical system 102, and the second monochromator 104, as described in the first embodiment.
One exit slit 14 emits. Exit slit 14
A detector unit 906 is arranged at the position of, and converts the intensity of the emitted light into an electric signal.

The control unit 130 controls the driving source 905 of the connection slit 401 and controls the dispersion element 50.
In this configuration, in addition to the control of the single rotation drive source 512, the control of the operation of all the units of the spectrophotometer is centrally performed. A personal computer 907 is connected to the control unit 130.

Next, the operation of the spectroscopic altimeter according to the second embodiment will be described.

When the operator inputs information such as the measurement wavelength range and the wavelength resolution to the personal computer 907, the control unit 130 connected to the personal computer 907
The input information is transmitted to.

The control unit 130 instructs the light source unit 901 to turn on / off and select a light source. For the sample chamber 902, an instruction to switch the sample side optical path and the reference side optical path that is in communication with the sample side optical path is issued. The chopper unit 903 is instructed to start, end, and operate the chopper. Also, the filter unit 9
For 04, an instruction is given as to which filter to select according to the measurement wavelength. Drive source 90 for connecting slit 401
With respect to 5, a slit width corresponding to the input wavelength resolution is commanded. In order to scan the measurement wavelength, a rotation angle range and a rotation speed of the diffraction grating 511 are instructed to the rotation drive source 512 of the dispersion element 501 in order to scan the measurement wavelength. The detection unit 906 is instructed to start and end the acquisition of the measurement signal.

As described above, the control unit 130 controls each part, so that the light emitted from the light source unit 901 passes through the sample or the reference in the sample chamber 902 and further passes through the chopper unit 903 and the filter unit 904. Thereafter, the light enters through the entrance slit 1 of the double monochromator, is split by the double monochromator, and only monochromatic light having the set wavelength exits through the exit slit 14. The intensity of the emitted light is detected by the detector unit 906.

Further, the control unit 130
Processing of the detected data is also performed. When the data processing is completed, data as a measurement result is returned to the personal computer 907. Personal computer 907
Displays the measurement results graphically, for example. Thereby, it is possible to measure the wavelength dispersion characteristics of the transmittance of the sample.

In the spectrophotometer of the second embodiment, since a double monochromator is used, high-purity light that does not include stray light can be emitted toward the detector 906, and the spectrophotometer can be highly accurately measured. A measurement can be made. In addition, the connection slit 401 and the integrated dispersion element 501
Is used, the setting of the slit width wavelength resolution of the entrance and exit slits 1 and 14 of the first and second monochromators and the setting of the rotation angle of the dispersion units 4 and 11 are performed by the two driving sources 905 and 512. Can be done at once by command. Therefore, it is possible to easily select the wavelength resolution and set the measurement wavelength.

[0051]

As described above, according to the present invention,
A double monochromator that can easily control the wavelength width of the emitted light and has high wavelength scanning accuracy can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing (a) an arrangement viewed from a top surface and (b) an arrangement viewed from a side surface of a double monochromator according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a detailed configuration of a monochromator optical system 101 in FIG.

FIG. 3 is an explanatory diagram showing a detailed configuration of a relay optical system 102 in FIG.

FIG. 4 is an explanatory diagram showing a detailed configuration of each of (a) a connection slit 401 and (b) a connection slit 402 of the double monochromator according to the first embodiment of the present invention.

FIG. 5 is a perspective view showing a detailed configuration of a dispersive element 501 of the double monochromator according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram illustrating a shape of a light spot at an exit slit of the double monochromator according to the first embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a conventional double monochromator.

FIG. 8 is a perspective view showing a configuration of a conventional double monochromator.

FIG. 9 is a perspective view illustrating a configuration of a spectrophotometer according to a second embodiment of the present invention.

FIG. 10 is a block diagram illustrating a configuration of a spectrophotometer according to a second embodiment of the present invention.

[Explanation of symbols]

1 ... entrance slit, 2, 3, 5 ... mirror, 4 ... dispersion part,
6 intermediate slit, 7 concave spherical mirror, 8 convex spherical mirror, 9 intermediate slit, 10, 12, 13 mirror, 1
DESCRIPTION OF SYMBOLS 1 ... Dispersion part, 14 ... Exit slit, 101 ... Monochromator optical system, 102 ... Relay optical system, 103 ... 1st monochromator, 104 ... 2nd monochromator, 110 ... Connection mirror, 120, 121, 122 ... Optical axis , 130 ... control unit, 401, 402 ... connecting slit,
403, 404, 405, 406 ... Slit blade, 40
7, 408, 409, 410 ... Slit blades, 411, 4
12, 413, 414: connecting portion, 415, 416: center line, 501: dispersion element, 511: plane diffraction grating, 512
... Rotary drive source.

Claims (4)

[Claims] An optical system includes a first monochromator optical system, a second monochromator optical system, and a relay optical system that causes light emitted from the first monochromator optical system to enter the second monochromator optical system. The first monochromator optical system includes an entrance slit, a first dispersion unit for dispersing the light incident from the entrance slit, and a first intermediate for passing the light dispersed by the first dispersion unit and emitting the light. A slit, and the second monochromator optical system includes a second intermediate slit, a second dispersion unit for dispersing light incident from the second intermediate slit, and light dispersed by the second dispersion unit. An exit slit that passes through and emits light, wherein the entrance slit and the exit slit are arranged side by side so that the center lines of the respective slit widths are aligned, and a pair of the entrance slits is formed. The blade is connected to a pair of blades constituting the outlet slit, and the first intermediate slit and the second intermediate slit are arranged so that center lines of respective slit widths are aligned, and the first and second intermediate slits are arranged in parallel. A pair of blades forming an intermediate slit is connected to a pair of blades forming the second intermediate slit, and the first dispersion portion and the second dispersion portion are connected such that a central axis is aligned. A double monochromator. 2. The double monochromator according to claim 1, wherein said relay optical system is an Offner type projection optical system for projecting an image of said first intermediate slit onto said second intermediate slit at an equal magnification. A double monochromator. 3. The double monochromator according to claim 1, further comprising a drive source for opening and closing said pair of blades of said connected entrance slit and exit slit. 4. A spectrometer comprising a light source unit, a sample holding unit for holding a sample, a monochromator unit for splitting light from the light source unit, and a detecting unit for detecting the intensity of the split light. A photometer, wherein the monochromator section causes a first monochromator optical system, a second monochromator optical system, and light emitted from the first monochromator optical system to enter the second monochromator optical system. A relay optical system, wherein the first monochromator optical system has an entrance slit, a first dispersion unit for dispersing the light incident from the entrance slit, and passes the light dispersed by the first dispersion unit. A second intermediate slit, a second dispersion unit for dispersing light incident from the second intermediate slit, and a second dispersion unit for dispersing light incident from the second intermediate slit. Minutes in the dispersing section An exit slit for passing and emitting the light, the entrance slit and the exit slit are arranged side by side so that the center line of each slit width is straight, a pair of blades constituting the entrance slit, The first intermediate slit and the second intermediate slit are connected to a pair of blades constituting the outlet slit, and are arranged so that center lines of respective slit widths are aligned, and the first intermediate slit is A pair of blades constituting the second intermediate slit is connected to a pair of blades constituting the second intermediate slit, and the first dispersion portion and the second dispersion portion are connected so that the central axis is aligned. Features a spectrophotometer.