JPH0431720A - Spectroscope for two-dimensional object - Google Patents

Abstract

PURPOSE:To perform the spectroscopy of each point of a two-dimensional body at the approximately same time by moving the two-dimensional body because a spectroscope can impart the spectrum of each point of the body in one-dimensional direction. CONSTITUTION:The light which is cast through an incident slit 52 in parallel with the direction of the grating of a diffraction grating 51 is converted into the parallel light through a concave mirror M1. The light is cast on the diffraction grating 51 and diffracted at an angle corresponding to a wavelength. The spectral distribution is imparted on a spectroscopic surface 53 which is conjugate with the incident slit 52 with a concave mirror M2. A two-dimensional photodetector 54 is arranged on the spectroscopic surface 53. The height of the slit 52 is made to correspond to the direction (y) of the incident surface, and the wavelength is made to correspond to the direction (x). Then, the distribution of intensity is measured. In this way, the spectroscopic measurement of a one-dimensional body corresponding to the incident position of the slit 52 can be performed. A two-dimensional body 55 is placed at the side front of the incident slit 52, and the spectroscopic measurement at the position of the body corresponding to the incident position of the slit 52 is performed. During this period, the two-dimensional body 55 is moved in the direction of (x). Thus, the spectrums from the points of the two-dimensional body 55 can be measured at the approximately same time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spectroscopic device that can substantially simultaneously analyze the emission and reflection/scattering spectra from each point of a two-dimensional object.

[Conventional technology]

Conventionally, as a spectroscopic device, a spectroscope using a diffraction grating, a Fourier spectrometer using a Michelson interferometer, or one using a spectroscopic element such as a colored glass filter or an interference filter has been widely used. However, since these conventional spectroscopic devices use a zero-dimensional detector on the east side of the output light, they are not designed to obtain spatial spectral information.

[Problem to be solved by the invention]

The present invention was made in view of this situation, and
The purpose is to provide a spectroscopic device that can accurately analyze the emission, reflection and scattering spectra from each point of a two-dimensional object in substantially real time.

[Means for Solving the Problems] A first spectroscopic device for a two-dimensional object according to the present invention that achieves the above object includes an entrance slit having a slit parallel to the grating direction of a diffraction grating, and a light emitted from the entrance slit. a condensing optical system that converts the light into parallel light, a diffraction grating that diffracts the light from the condensing optical system, an imaging optical system that forms an image of the light diffracted by the diffraction grating, and a This device is characterized by comprising a spectroscope consisting of a dimensional photodetector, and means for moving a two-dimensional object placed in front of the entrance slit in a direction intersecting the slit of the entrance slit.

In addition, the second two-dimensional object spectrometer of the present invention includes a plurality of highly directional optical elements that transmit only plane waves incident on the input end from a predetermined direction to the output end in a one-dimensional direction parallel to the grating direction of the diffraction grating. A one-dimensional multi-optical high-directivity optical system bundled in parallel in the direction, a condensing optical system that converts light from the output end of the one-dimensional multi-optical high-directivity optical system into parallel light, and a condensing optical system. a spectrometer consisting of a diffraction grating that diffracts light from the diffraction grating, an imaging optical system that forms an image of the light diffracted by the diffraction grating, and a two-dimensional photodetector placed on the imaging plane; The optical system is characterized by comprising means for relatively moving a two-dimensional object placed in front of the input end in a direction intersecting the longitudinal direction of the input end of the raised directional optical system.

In addition, the third two-dimensional object spectrometer includes a plurality of highly directional optical elements parallel to the grating direction of the diffraction grating that transmits only a plane wave that enters the input end from a predetermined direction to the output end and emits it as a plane wave. A one-dimensional multi-optical high-directivity optical system bundled in parallel in one-dimensional direction, a diffraction grating that diffracts a plane wave from the output end of the one-dimensional multi-optical high-directivity optical system, and light diffracted by the diffraction grating. an imaging optical system that forms an image in a direction perpendicular to the grating direction of the diffraction grating, a spectrometer consisting of a two-dimensional photodetector placed on the imaging plane, and the one-dimensional multi-optical highly directional optical system. It is characterized by comprising means for relatively moving a two-dimensional object placed in front of the entrance end in a direction intersecting the longitudinal direction of the entrance end.

The fourth two-dimensional object spectroscopy device is a highly directional optical element array that is made up of a plurality of highly directional optical elements that are bundled in parallel in a column direction and that transmit only plane waves incident on the input end from a predetermined direction to the output end. A plurality of optical elements are stacked in the row direction at the input end of the multi-beam high-directivity optical system arranged in a matrix, and a second or third optical element is arranged at the output end of each of the high-directivity optical element arrays. The present invention is characterized in that the spectroscopes used in the spectroscopic device are arranged separately, and a two-dimensional object is arranged at the input end of the multi-beam highly directional optical system.

Furthermore, the fifth two-dimensional object spectroscopic device of the present invention is constructed by arranging a plurality of highly directional optical elements in parallel in the row direction, which transmit only plane waves incident on the input end from a predetermined direction to the output end. A plurality of highly directional optical element arrays are stacked in the row direction at their input ends to serve as the input end of a multi-beam high directional optical system arranged in a matrix, and each output end of the highly directional optical element array is A spectrometer used in a second or third spectrometer at the output end of the multi-beam high-directivity optical system arranged in parallel in the column direction in one row, and at the output end of the multi-beam high-directivity optical system. and a two-dimensional object is arranged at the input end of the multi-beam highly directional optical system.

The sixth two-dimensional object spectrometer is configured such that the two-dimensional object is placed at the front focus of the condensing lens of the Michelson interference system, and the two-dimensional object is placed at the back focus of the imaging lens of the Michelson interference system.
When a dimensional photodetector is placed and the movable mirror of the Michelson interference system is moved, the interferogram signals obtained from multiple predetermined sampling positions on the detection surface of the 2D photodetector are sampled by Fourier transformation. The present invention is characterized in that it includes means for determining the spectrum of light from the position of the two-dimensional object corresponding to the position.

The seventh two-dimensional object spectrometer uses a highly directional optical element that transmits only a plane wave that enters the input end from a predetermined direction to the output end and emits it as a plane wave instead of the condensing lens of the Michelson interference system. 2 bundled in parallel in two-dimensional direction
A multi-dimensional multi-optical highly directional optical system is arranged, a two-dimensional object is arranged at the input end of the two-dimensional multi-optical optical system, and the imaging lens of the Michelson interference system is omitted. Instead, a two-dimensional photodetector is placed on the output side of the Michelson interference system, and when the movable mirror of the Michelson interference system is moved, the information obtained from multiple predetermined sampling positions on the detection surface of the two-dimensional photodetector is The present invention is characterized by providing means for Fourier transforming the interferogram signals to obtain the spectrum of light from the position of the two-dimensional object corresponding to the sampling position.

Any of the two-dimensional object spectroscopy devices of the present invention described above can be used as a two-dimensional microspectroscopy device, and the two-dimensional microspectroscopy device magnifies a plane wave emitted from a two-dimensional object in a predetermined direction and emits it as a plane wave. It is equipped with an optical system.

[Effect]

According to the first to third spectroscopic devices for two-dimensional objects of the present invention, since the spectrometer can provide a spectrum at each point of the object in one-dimensional direction, by moving the two-dimensional object, The spectroscopy of each point can be performed almost simultaneously.

According to the fourth and fifth spectroscopic devices for two-dimensional objects of the present invention, the input end has a multi-beam highly directional optical system with a two-dimensional array and a spectrometer used in the second or third spectroscopic device. Since the two-dimensional object is used, spectroscopy of each point on the two-dimensional object can be performed simultaneously without moving the two-dimensional object.

According to the sixth and seventh two-dimensional object spectrometers of the present invention, in the Fourier transform spectrometer using a Michelson interference system, a two-dimensional photodetector is used as a photodetector;
Since the light from the point of the two-dimensional object substantially corresponding to that point is incident on each point on the dimensional detection surface while interfering, the interferometry obtained from a plurality of predetermined sampling positions on the detection surface is By Fourier transforming each of the gram signals, it is possible to obtain the spectrum of light from the position of the two-dimensional object corresponding to the sampling position.

In addition, in the sixth two-dimensional object spectrometer of the present invention,
The size of the minimum unit detector of a dimensional photodetector is the zero-order spectrum ( (corresponds to the part within the first dark ring of the Airy disk). Therefore, if the smallest unit detector is relatively large, F
It is necessary to use an imaging lens with a large value.

If the size of the minimum unit detector is larger than the 0th order spectrum of the Fraunhofer diffraction image, interference fringes with temporally shifted phases will enter the minimum unit detector at the same time, resulting in changes in the interference fringes over time. becomes undetectable.

In addition, in the seventh two-dimensional object spectrometer at the main station, the Fresnel diffracted light determined by the distance from the exit of the highly directional optical element to the detector overlaps with the Fresnel diffracted light from the adjacent exit. Moreover, it is necessary to arrange the output light so that each emitted light is detected by a minimum unit detector.

According to the second to fifth and seventh two-dimensional object spectrometers of the present invention, a multi-beam highly directional optical system is used to guide the light from the two-dimensional object to the spectrometer. , selectively separates and spectrally spectra only plane waves emitted from a two-dimensional object in a predetermined direction. Therefore, it is particularly suitable for simultaneously performing spectroscopy on each point of a directional light-emitting object or reflective object.

〔Example〕

Before explaining the present invention in detail, we will briefly discuss the multi-beam high-directivity optical system used in some embodiments of the present invention.

The inventors of the present invention
No. 50034, in order to separate and extract the plane waves mixed in the scattered light and observe them, the zero-order spectrum (
This corresponds to the portion within the first dark ring of the Airy disk. ), and it was shown that by doing so, most of the scattered components could be removed.

As a highly directional element that realizes such observation, two pinholes P, which are separated from each other as shown in Figure 1, are used.
, P, was proposed. In this optical system, the zero-order light is detected by the detector 23 through the pinhole P2. Further, as shown in FIG. 2, a highly directional optical element is made of a straight, elongated hollow glass fiber 35, and the inner wall surface of the highly directional optical element is coated with a light absorbing material, such as an absorbing material 35 such as carbon. proposed. In such an optical element, if the aperture diameter and length are set appropriately according to the measurement target and the optical element is made sufficiently long compared to the entrance aperture diameter, out of the light incident on the highly directional optical element, Only plane waves parallel to the optical axis can be extracted from the exit surface. Furthermore, the authors also proposed that by bundling a plurality of such highly directional optical elements to form a multi-beam highly directional optical system, only plane waves having a two-dimensional intensity distribution can be extracted.

By the way, in highly directional optical elements such as those shown in Figs. 1 and 2, at a distance where the Franfau core diffraction image can be observed, the 0th-order diffraction image of the Franfau core diffraction (the Airy disk's 1 dark ring) is larger than the diameter of the aperture on the entrance side, and if an extraction aperture with the same size as the diameter of the entrance side is used, only a part of the 0th order diffraction image can be taken out, and the observation point is far away. It was found that the larger the first dark ring becomes, the smaller the energy extracted from the extraction opening becomes. Therefore, as shown in Figure 3,
The diffracted wave by the entrance aperture P is made incident on the convex lens L, and a pinhole P having a diameter approximately equal to the first dark ring of the diffraction image is arranged on the focal plane of the convex lens L, so that most of the 0th order diffraction image is It has been found that by taking out the light, a brighter and highly directional optical element can be constructed. This element allows the diameter of the pinhole P2 to be smaller than the diameter of the inlet opening. In this case, the artificial aperture P1 is the aperture P of the lens L. It can be yourself. In this element, the relationship between the size of the zero-order diffraction image and the aperture P1 will be determined. The diameter of the first dark ring of the Airy disk in the diffraction image by the lens is D = 2.442・f/D, (
1). Here, Dr is the diameter of the aperture P1, and f is the focal length of the lens L. If we find the condition for the aperture diameter Dr to be greater than or equal to the diameter of the first dark ring, we get the following: Dr”≧2.44λ・f −−−−−−−(2).Satisfy this condition by using a convex lens. It is extremely easy to construct a highly directional optical element.To give a numerical example, for example, when using light with a wavelength λ of 500 nm, a convex lens with a focal length f of 5 cm is used for an aperture diameter Dr of 1 mm. and the first Airy disk.
The diameter of the dark ring is 6. When using a convex lens with lXl0-2mm and focal length iff of 10cm, the diameter of the first dark ring is 1
．． 22XlO-'mm, which indicates that the condition of formula (2) is satisfied. If a highly directional optical element that satisfies the condition of equation (2) is used as a unit, a multi-beam highly directional optical system can be constructed by arranging a large number of highly directional optical elements closely adjacent to each other. Even if all the plane waves are taken in, adjacent plane waves will not interfere with each other (,
For example, a light emission image riding on a two-dimensional plane wave whose intensity differs depending on the location can be observed with high resolution.

Next, a specific example of this highly directional optical element will be explained. Fourth
What is shown in the figure consists of an objective lens ob, which is, for example, a microscope objective lens that satisfies the relationship of formula (2) above, and a pinhole P placed in its focal plane. It allows only the 0th order diffraction image of four core diffraction to pass through. Also, Fig. 5(a)
shows another form of convex lens GL. This is known under the trade name "Selfoc Lens" and is also called a gradient index lens. This lens has a refractive index that gradually decreases from the central axis to the periphery, and has a light condensing effect similar to a convex lens. By appropriately selecting the length,
The focal plane can be made to coincide with the end face of the cylinder. At the focal plane of one end of such a gradient index lens GL, the 51st
As shown in FIG. 1(b), a pinhole P similar to that in FIG. 4 may be arranged to allow only the zero-order diffraction image of Franfau core diffraction to pass through.

Incidentally, among optical fibers, there are multimode fibers, graded index fibers, single mode fibers, etc. Among these, single mode fibers have an extremely small core diameter, and only the light incident on the core end face at the input end is transmitted. It has the property of not allowing light to pass through and making a large angle to the axis, and as shown in Figures 4 and 5 (
2 can be used in place of the pinhole P in b). Furthermore, since the aperture of the single mode fiber has a value that matches the first dark ring of Franhoefer diffraction of the objective lens Ob or the gradient index lens GL, only the 0th-order diffraction image of Franhoefer core diffraction is efficiently combined. It is convenient for conveying information. Furthermore, since an optical fiber is used for the extraction part, the light can be guided to any desired location, which is advantageous in terms of arrangement.

Fig. 6 shows an example in which a single mode fiber SM is arranged at the focal point of the objective lens Ob to configure a highly directional optical element, and Fig. 7 shows an example in which a single mode fiber SM is arranged at the focal point of one end of the gradient index lens GL. An example in which a highly directional optical element is constructed is shown below.

In the case of a lens with a long focal length, it is also possible to make the first dark ring of Franhofer diffraction caused by the lens the same as the aperture of the multimode fiber. For example, by inserting an aperture in front of the lens and decreasing its diameter, the first dark ring can be made to match the aperture of the multimode fiber. In such cases, multimode fibers can also be used.

A plane wave that passes through a highly directional optical element such as the one described above leaves the element as a spherical wave that diverges.

For example, when a photodetector is placed behind the pinhole P to measure the absorption rate, the emitted light may diverge in this way, but for example, if a large number of highly directional optical elements are bundled, When a multi-beam, high-directivity optical system is configured to detect a distribution image of a reflective and scattering object, it is desirable to configure the light beam to exit as a plane wave from each high-directivity optical element. Several such configurations are shown in FIGS. 8-11. In the case of Fig. 8, an objective lens Ob2 similar to the objective lens ○b1 on the input side is placed on the output side so that its focal point coincides with a pinhole P placed in the middle.
The 0th order diffraction image passes through the pinhole P and becomes a spherical wave,
It is converted back into a plane wave by the objective lens Ob2. In the case of FIG. 9, a gradient index lens GL2 similar to the gradient index lens GLI disposed before and after the pinhole P in FIG. 5(b) is placed confocal.

The one shown in FIG. 10(a) uses a single mode fiber SM in place of the pinhole P in FIG. 8. Note that, as shown in figure (b), one objective lens O
A gradient index lens GL may be used instead of bl or Ob2. In this case, the first dark ring of Franhofer diffraction of the gradient index lens GL and the objective lens Obl or ○b
It is necessary that the first dark ring of No. 2 substantially coincide with the first dark ring of No. 2. The one shown in FIG. 11 uses a single mode fiber SM instead of the pinhole P shown in FIG.

None of the highly directional optical elements described above can simultaneously detect plane waves having a two-dimensional distribution. Therefore, it may be necessary to arrange a large number of these highly directional optical elements two-dimensionally to configure a multi-beam, highly directional optical system. First, let's look at an example where the emitted light becomes diverging light.
This will be explained with reference to FIGS. 2 to 15. The multi-beam high-directivity optical system shown in FIG. 12 corresponds to one in which a large number of high-directivity optical elements shown in FIG. 5(b) are arranged in parallel. First, a large number of similar graded refractive index lenses GL are arranged in a stacked pattern in a regular manner within a frame, and they are adhered to each other using adhesive strips made of black silicone resin, for example, and light leaks backward through the gaps. Make sure not to. A pinhole array PA is closely attached to the rear surface of the gradient index lens array GA thus formed. Each pinhole of the pinhole array PA is provided so as to coincide with the axis of each gradient index lens GL. On the other hand, when a plane wave having a two-dimensional intensity distribution enters the t1 gradient index lens array GA from the front of the gradient index lens array GA, the intensity of the light passing through each pinhole of the pinhole array PA will change according to the distribution. Different according to. Therefore, by placing a separate photodetector behind each pinhole or by placing a two-dimensional light intensity detector behind the pinhole array PA, the two-dimensional intensity distribution of the plane wave can be measured. Furthermore, the multi-beam high-directivity optical system shown in Fig. 13 corresponds to one in which a large number of high-directivity optical elements shown in Fig. 4 are arranged in parallel. is used. Flat plate microlens PM is produced by fabricating a regular array of tiny lenses on a transparent plate using, for example, photolithographic techniques, or by fabricating gradient index lenses regularly by techniques such as ion exchange or ion implantation. It was created in an array. And a pinhole 7L/IP having a pinhole corresponding to the focal point position of each microlens.
By arranging A on the focal plane of the flat microlens PM, a multi-beam highly directional optical system similar to the multi-beam highly directional optical system shown in FIG. 12 can be constructed. Further, the multi-beam high-directivity optical system shown in FIG. 14 corresponds to one in which a large number of high-directivity optical elements shown in FIG. 7 are arranged in parallel. That is, on the rear surface of the gradient index lens array GA explained in FIG. 12, there is a single mode fiber array formed by bending a large number of single mode fibers SM corresponding to the axis of each gradient index lens of the lens array GA. A single mode fiber array SA is used in place of the pinhole array FA shown in FIG. 12 to provide the same effect. Further, the one in FIG. 15 uses an array SH of single mode fibers SM similar to the single mode fiber array SA in place of the pinhole array PA in the one in FIG. 13.

This array SH is provided with supports S at both ends, and each support S
In this example, a number of apertures equal to the diameter of the single mode fiber SM are provided around the focal point of each microlens of the flat plate microlens PM, and the input end and output end of the single mode fiber SM are inserted into each aperture. Single mode fibers SM are regularly arranged.

By the way, in the multi-beam high-directivity optical system shown in FIGS. 12 to 15, the emitted light becomes diverging light, as described above. If the emitted light comes out as diffused light from the emission point on the rear surface of the pinhole array PA, etc., detectors such as two-dimensional light intensity detectors cannot be placed too far apart (if they are too far apart, they will be placed adjacent to each other). Channels cause interference,
It becomes impossible to measure the intensity distribution. ). Therefore,
It is possible to construct a multi-beam highly directional optical system in which the emitted light is emitted as a plane wave with a distribution similar to that of the incident light. Examples are shown in FIGS. 16 to 19.

16th I! The multi-beam high-directivity optical system I corresponds to one in which a large number of high-directivity optical elements shown in FIG. 9 are arranged in parallel.

To configure this optical system, a pinhole array PA is arranged between the two gradient index lens arrays GAI and GA2 explained in connection with FIG. 12, and the axis and pin of each gradient index lens are Each pinhole in the hole array FA is aligned and brought into close contact. With this configuration, scattered light from an incident plane wave with a two-dimensional intensity distribution is removed by this multi-beam highly directional optical system and output as a plane wave with a two-dimensional intensity distribution as well. Even if a detector such as a two-dimensional light intensity detector is placed at a certain distance from this multi-beam highly directional optical system, the intensity distribution can be measured two-dimensionally. The multi-beam high-directivity optical system shown in FIG.
A second flat plate microlens PM2 is arranged confocally behind the multi-beam highly directional optical system shown in FIG. Also,
The multi-beam high-directivity optical system shown in FIG. 18 corresponds to one in which a large number of high-directivity optical elements shown in FIG. 11 are arranged in parallel. A detailed explanation may not be necessary. Furthermore, the multi-beam high-directivity optical system of No. 195U includes a second flat microlens PM2 at the core of the output end of each single mode fiber of the array SH, behind the multi-beam high-directivity optical system of FIG. The images are arranged so that the front focal points of the images coincide with each other.

Now, the two-dimensional object spectroscopic apparatus of the present invention will be explained. First, FIG. 20 shows the diffraction grating 51 and concave mirrors M1, M2,
A grating spectrometer consisting of an entrance slit 52 is shown. The light incident from the entrance slit 52 parallel to the grating direction of the diffraction grating 51 is converted into traveling light by the concave mirror M1, and the light enters the diffraction grating 51.
The beam enters the beam and is diffracted at an angle corresponding to the wavelength, and a concave mirror M2 imparts a spectral distribution to a spectral surface 53 conjugate to the incident slit 52. If light with different spectral characteristics is incident on the entrance slit 52 depending on its height, the spectrum of the light that has entered the entrance slit 52 at the position of that height in the height direction (X direction) of the slit 52 on the spectral plane 53 (The spectral distribution is distributed in the X direction.)

Therefore, by arranging the two-dimensional photodetector 54 on the spectral plane 53 and measuring the intensity distribution by matching the height of the slit 52 in the X direction of the incident plane and the wavelength in the X direction, the intensity distribution of the slit 52 can be measured. It is possible to perform spectroscopic measurements of a one-dimensional object corresponding to the incident position. In addition, a two-dimensional object to be measured 55 is placed in front of the entrance slit 52, and the two-dimensional photodetector 54 detects the
By moving the two-dimensional object 55 in the X direction in the figure while performing spectroscopic measurements at the object position corresponding to the incident position of the slit 52, spectra from each point of the two-dimensional object 55 can be measured almost simultaneously. For this purpose, move 2 in the direction of the double arrows in the figure.
A mechanism for moving the dimensional object 55 is provided. Although this mechanism is not shown, various known means may be used. In addition, 2
The dimensional object 55 and the slit 52 are spatially separated, and an imaging optical system is provided between them, so that the image of the two-dimensional object 55 is transferred to the slit 5.
The image of the two-dimensional object 55 on the slit 52 may be scanned by interposing a deflection optical system such as a galvano mirror in this optical path.

The example in FIG. 20 is an example in which the two-dimensional object to be measured 55 is placed directly in front of the entrance slit 52, but this object is placed away from the spectrometer, and the space between the slit 52 and the surface of the object 55 is It is also possible to separate the incident light from each point of a two-dimensional object by connecting the multi-beam high-directivity optical system or optical fiber east described in FIGS. 12 to 19. An example is shown in FIG. East, indicated by reference numeral 56, is a multi-beam high-directivity optical system in which the incident plane wave explained in FIGS. 12 to 15 is converted into diverging light from the output point of each high-directivity optical element, and They are bundled in parallel only in one dimension. In this case, since the output end of the one-dimensional array multi-beam high-directivity optical system 56 acts as the entrance slit 52, t
It is not necessary to arrange one slit 52. When such a multi-beam highly directional optical system 56 is used, only the light emitted from the object 55 in a predetermined direction is selectively separated and incident on the spectrometer, and the spectrum is measured. This is effective for measuring the reflection and scattering spectra of . When the multi-beam highly directional optical system 56 shown in FIGS. 14 and 15 is used, since a single mode optical fiber is used, flexibility is provided between the input end and the output end. Therefore, instead of moving and scanning the two-dimensional object 55 itself, the input end of the multi-beam highly directional optical system 56 is scanned along the surface of the object 55 to capture plane waves from the object. can do. Note that a one-dimensional array of optical fibers may be used instead of the multi-beam high-directivity optical system.

By the way, as shown in FIGS. 16 to 19, there is a multi-beam highly directional optical system that separates only plane waves emitted from an object in a predetermined direction and extracts them as plane waves.

FIG. 22 shows an example using the multi-beam highly directional optical system 57 that outputs an incident plane wave as a plane wave. Since the light emitted from the multi-beam highly directional optical system 57 is a plane wave, the first concave mirror Ml in FIG. 21 is no longer necessary. Further, it is necessary to replace the second concave mirror M2 with a concave cylindrical mirror M3 whose generatrix is oriented in the X direction. therefore,
In the spectrometer shown in FIG. 22, the diffracted light emitted from the diffraction grating 51 enters the concave cylindrical mirror M3 and is focused only in the direction perpendicular to the y-axis, producing a spectrum corresponding to the position in the X direction on the spectral plane 53. give.

By the way, in the spectrometers shown in Figs. 20 to 22, 2
To separate the light from each point of the dimensional object 55, the object is moved in front of a slit etc. for scanning, or a multi-beam highly directional optical system or the input end of the optical fiber east is scanned along the object surface. have to move. To avoid this, it is possible to simultaneously separate light from each point of a two-dimensional object without performing any mechanical movement. An example of this is shown in Figure 23 and 2.
Shown in Figure 4. In the example of Fig. 23, assuming that the surface of a two-dimensional object is on the x-y plane, as shown in Fig. 23, the surface of the two-dimensional object is divided into m rows and n columns, and one The input end of the multi-beam high-directivity optical system or optical fiber east 58 is configured such that the input ends of the high-directivity optical elements or optical fibers correspond to each other, and the other end of the multi-beam high-directivity optical system or optical fiber east 58 is configured. In this case, each row of input ends branches into a corresponding one-dimensional array, and each output end of the one-dimensional array is divided into a second array.
As shown in FIG. 1 or FIG.
1o.

In this way, without moving the two-dimensional object, the multi-beam highly directional optical system, or the input end of the optical fiber east 58, it is possible to measure points corresponding to each point of the object to be measured, as shown in (a) of the figure. A spectrum is obtained. The one in FIG. 23 includes a large number of spectrometers 1. ~1. ．． If you do not use the
An example in which spectroscopy can be performed at each point simultaneously at 0 is shown in FIG. That is, in this case, the output end of the multi-beam highly directional optical system or the optical fiber east 59 is arranged in such a way that each row of the input end is connected vertically to form a single row, so that only one spectrometer 10 is required. It will be a good thing. Incidentally, such an element arrangement relationship between the input end and the output end is well known as a line-raster transducer or a surface-line transducer in an optical fiber bundle.

Now, the above was about finding the spectrum of light from each point of a two-dimensional measured object using a diffraction grating spectrometer.
A Fourier spectrometer using a Michelson interferometer can similarly perform spectroscopy of light from each point of a two-dimensional object. An example of this will be explained with reference to FIGS. 25 to 27. In the example of FIG. 25, as shown in (a) of the figure, the two-dimensional object 55 is placed on the front focal plane of the condenser lens L of the Michelson interference system. The light emitted from each point of the object 55 is converted into parallel light by this lens L, and this parallel light is split into two by the beam splitting mirror HM. One hits the fixed mirror M and is reflected.
The light passes through M, enters the imaging lens L, and forms an image at a conjugate position on the rear focal plane. The other parallel light enters the movable mirror M, is reflected, is reflected by the beam splitting mirror HM, enters the imaging lens L, and forms an image at a conjugate position on the rear focal plane. One light and the other light overlap and form an image on the rear focal plane of the imaging lens L2, but since both lights are coherent, if a photodetector is placed at this position, the movable mirror M, As it moves, an interferogram signal is obtained from its photodetector.

Therefore, corresponding to each point of the object 55, the imaging lens L,
A spectrum of each point on the two-dimensional object 55 is obtained by arranging a large number of photodetectors on the rear focal plane and Fourier transforming the interferogram signals obtained from each photodetector. However, the size of each photodetector must be smaller than the zero-order Franhofer diffraction image determined by the aperture and focal length of the imaging lens L2 and the shortest observed wavelength. Instead of arranging a large number of photodetectors on the rear focal plane of the imaging lens L2, a two-dimensional photodetector 54 having a photoelectric conversion surface 60 is arranged on this focal plane as shown in FIG. As shown in Fig. 6, the photoelectric conversion surface 60
Divide the area into a predetermined number of areas, and each partition (x+5yJ)
Separately take the interferogram signals from the
What is necessary is to obtain the spectrum of a point or region. However, the area of the photoelectric conversion surface 60 is divided into a predetermined number of areas, each of which operates independently. It is necessary to install a light-shielding plate with a pinhole having a diameter smaller than the following Fraunhofer diffraction image. The obtained spectrum is taken on the wavelength λ axis and the area of the two-dimensional object 55 (Xt, Y
, +), x- as shown in (C) of the figure
A y-λ space is obtained, and this space allows the two-dimensional object 55
The spectrum of each point is represented. A system configuration diagram of such a Fourier spectrometer is shown in FIG. 26. In the figure, reference numeral 61 indicates a Michelson interferometer, and 62 indicates a two-dimensional photodetector 5.
An amplifier that amplifies the signal from each pixel channel of 4,
63 is a sample hold circuit and an A/D converter; 64 is a sample hold circuit and an A/D converter;
6 shows the movable mirror M and the drive mechanism, and 65 shows the computer.

To give an overview of the system, light from each point of the two-dimensional object 55 passes through an interferometer 61 and forms an image on the corresponding pixel channel of the two-dimensional photodetector 54 while interfering with each other. Generates a ferrogram signal. The interferogram signal corresponding to each pixel is sent to the amplifier 6
2, is sampled and A/D converted by a sample hold circuit and an A/D converter, is taken into a computer 65, is Fourier transformed for each channel by the computer 65, and is converted into a two-dimensional object 55 corresponding to that pixel. The spectrum of the point or region is shown in Figure 25 (C).
It can be found in the format: Note that the movable mirror M is moved by a movable mirror drive mechanism 64 controlled by a computer 65.

In the case of the example shown in FIG. 25, the interferogram at each point is created by giving a phase difference due to an optical path difference to the divergent light of the object 55, causing interference.

Therefore, the interference light beam at a point outside the center of the detection surface becomes a light beam with a large radiation angle, and even though it is interference of light beams from the same point, it becomes interference of radiation beams of different angles. Therefore, when the spatial radiation intensity of light emission or reflection from an object is strong in the forward direction, that is, when the light emission or reflection is directional, the light beams in the direction of strong directionality in front of the object interfere to form an interferogram. The luminous flux detection efficiency becomes better. In such a case, the condenser lens L shown in FIG.
The Is imaging lens L is removed, and instead, as shown in FIG. 27(a), a multi-beam highly directional optical system 66 (16th to 1st
(see Figure 9). In this way, the two-dimensional area of the object 55 is divided by each element of the multi-beam high-directivity optical system 66, and only the plane waves emitted from the two-dimensional area are divided into two-dimensional areas by the photoelectric conversion surface 60 of the two-dimensional photodetector 54 while being separated. and remain separated to generate interferogram signals separately. Therefore, by Fourier transforming this interferogram, the spectrum of the plane wave from the two-dimensional object 55 corresponding to that section can be obtained. Note that the multi-beam high-directivity optical system 66, as shown by the dotted line in the figure,
It may be arranged in front of the photoelectric conversion surface 60. Furthermore, it may be placed both in front of the two-dimensional object 55 and in front of the photoelectric conversion surface 60. Even when obtaining an interferogram signal using diverging light from the object 55, if you want to limit the sample points on the object surface to a small area, use multi-beam high-directivity optics as shown in Fig. Instead of the system 66, it is possible to arrange a pinhole array PA and a lens array LA whose front focus coincides with each pinhole, so that the light from each sample point becomes parallel and enters the interference system. .

Next, an example in which the two-dimensional object spectroscopic apparatus of the present invention as described above is applied to a minute object will be described.

In the two-dimensional microspectroscopy apparatus of the present invention shown in FIG.
Expanded by The magnifying lens system 70 is configured as a magnifying optical system in order to emit light parallel to the optical axis from the surface of a minute object in parallel to the optical axis. That is, the magnifying lens system 70 consists of an objective lens 68 with a relatively short focal length and a convex lens system 69 with a relatively long focal length, and the rear focus of the objective lens 68 and the front focus of the convex lens system 69 coincide to form a confocal lens. ), and the light emitted in parallel from the object also passes through this system 70 and exits as parallel light. When such an enlarging optical system is used as the enlarging lens system 70, it is convenient because the rectilinear component of the light emitted from the surface of the two-dimensional object is maintained even if the image is enlarged. There are other features such as a deep depth of focus, but the most important feature of this two-dimensional microspectroscopy device is that the spectrometer can be When the measurement light is incident, a multi-beam light directional optical system (symbol 71 in Fig. 28) is used.
This is a representative example. ) when using the spectrometer 72 as its spectroscopic system, the input end face of the multi-beam light directional optical system 71 no longer needs to be placed in a position conjugate with the minute object placed on the sample stage 67. That's true. Therefore, in such a case, the magnifying lens system 70
There is no need to precisely adjust the focus. By the way, as the spectrometer 72, the above-mentioned FIGS. 21 to 24 and FIG.
), but it is preferable to use one of the following:
When using a spectroscope as shown in FIG. 25(a) or FIG. 27(b), the multi-beam light directional optical system 71 is omitted, and each magnified image position conjugate to the sample of the magnifying lens system 70 is The spectrometer objects 55 must be arranged so that they match.

Although several embodiments of the two-dimensional object spectroscopy apparatus of the present invention have been described above, the present invention is not limited to these and various modifications are possible.

〔Effect of the invention〕

According to the first to third spectroscopic devices for two-dimensional objects of the present invention, since the spectrometer can provide a spectrum at each point of the object in one-dimensional direction, by moving the two-dimensional object, The spectroscopy of each point can be performed almost simultaneously.

According to the fourth and fifth spectroscopic devices for two-dimensional objects of the present invention, the input end has a multi-beam highly directional optical system with a two-dimensional array and a spectrometer used in the second or third spectroscopic device. Since the two-dimensional object is used, spectroscopy of each point on the two-dimensional object can be performed simultaneously without moving the two-dimensional object.

According to the sixth and seventh two-dimensional object spectrometers of the present invention, in the Fourier transform spectrometer using a Michelson interference system, a two-dimensional photodetector is used as a photodetector;
Since the light from the point of the two-dimensional object substantially corresponding to that point is incident on each point on the dimensional detection surface while interfering, the interferometry obtained from a plurality of predetermined sampling positions on the detection surface is By Fourier transforming each gram multiple, it is possible to obtain the spectrum of light from the position of the two-dimensional object corresponding to the sampling position.

According to the second to fifth and seventh two-dimensional object spectrometers of the present invention, a multi-beam highly directional optical system is used to guide the light from the two-dimensional object to the spectrometer. , selectively separates and spectrally spectra only plane waves emitted from a two-dimensional object in a predetermined direction. Therefore, it is suitable for simultaneously performing directional emission spectroscopy and reflection/scattering spectroscopy at each point.

[Brief explanation of the drawing]

Figures 1 to 3 are diagrams for explaining the basic principles of highly directional optical elements, Figures 4 to 11 are diagrams for explaining examples of highly directional optical elements, and Figure 12. from 1st
Figure 9 is a diagram for explaining an example of a multi-beam highly directional optical system used in some embodiments of the present invention, respectively.
FIG. 20 is a diagram for explaining the configuration and operation of the first two-dimensional object spectroscopic device of the present invention, and FIGS. 21 to 25 are diagrams for explaining the configuration and operation of the second to sixth spectroscopic devices. Fig. 26 is a system configuration diagram of the 6th spectroscopic device, Fig. 27
The figure is a diagram for explaining the configuration and operation of the seventh spectroscopic device,
FIG. 28 is a diagram for explaining the configuration and operation of the two-dimensional microspectroscopy apparatus according to the present invention. L... Convex lens, P O... Lens aperture, Pl...
・Inlet opening, P2... pinhole, Ob, Obl, O
b2...Objective lens, P...Pinhole, GLSG
LI, GL2...Gradient index lens, SM...Single mode fiber, B...Adhesive, G, ASGA
I, GA2...Gradient index lens array, PA...
Pinhole array, PM, PMI, PM2...flat plate microlens, SA...single mode fiber array, SH...single mode fiber array, S
...Support, Ml, M2...Concave mirror, M3...Concave cylindrical mirror, L...Condensing lens, L...Imaging lens,
HM...Beam splitting mirror, M5...Fixed mirror, M...
...Moving mirror, LA...Lens array, 1. ~1o, 10
...Spectroscope, 51...Diffraction grating, 52...Incidence slit, 53...Spectral surface, 54...Two-dimensional photodetector, 55...Two-dimensional object, 56.57.58 .59.6
6.71... Multi-beam highly directional optical system, 60... Photoelectric conversion surface, 61... Michelson interferometer, 62... Amplifier, 63... Sample and hold circuit and A/D converter , 64... Moving mirror drive mechanism, 65... Computer, 67... Sample stage, 68... Objective lens with short focal length, 69... Convex lens system with long focal length, 70
...Magnifying lens system, 72...Spectroscope Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. , A2 0.1 Fig. 7 L Fig. 12 Fig. PM+Shakuyu 74 Groreno entry Fig. 14 Fig. 16 Fig. 18 Fig. 19 Fig. 19 MI MZ Fig. 21 Fig. 24 Fig. 27 Fig. 28

Claims (8)

[Claims] (1) An entrance slit with a slit parallel to the grating direction of the diffraction grating, a condensing optical system that converts the light from the input slit into parallel light, a diffraction grating that diffracts the light from the condensing optical system, and a diffraction grating. An imaging optical system that forms an image of the diffracted light, a spectroscope consisting of a two-dimensional photodetector placed on the imaging plane, and a spectroscope placed in front of the entrance slit in a direction intersecting the slit of the entrance slit. 1. A spectroscopic device for a two-dimensional object, comprising means for moving the two-dimensional object. (2) One-dimensional multi-luminous flux highly directional, in which multiple highly directional optical elements that transmit only plane waves incident on the input end from a predetermined direction to the output end are bundled in parallel in a one-dimensional direction parallel to the grating direction of the diffraction grating. a condensing optical system that converts the light from the output end of the one-dimensional multi-beam high-directivity optical system into parallel light, a diffraction grating that diffracts the light from the condensing optical system, and a diffraction grating that diffracts the light from the condensing optical system. an imaging optical system that forms an image of light, a spectroscope that includes a two-dimensional photodetector placed on the imaging surface, and a direction that intersects the longitudinal direction of the input end of the one-dimensional multi-beam highly directional optical system. and means for relatively moving a two-dimensional object placed in front of its entrance end. (3) A plurality of highly directional optical elements that transmit only a plane wave that enters the input end from a predetermined direction to the output end and output it as a plane wave are bundled in parallel in a one-dimensional direction parallel to the grating direction of the diffraction grating. A diffraction grating that diffracts a plane wave from the output end of a dimensional multi-beam highly directional optical system and a one-dimensional multi-beam highly directional optical system, and a diffraction grating that directs the light diffracted by the diffraction grating in a direction perpendicular to the grating direction of the diffraction grating. a spectrometer consisting of an imaging optical system that forms an image and a two-dimensional photodetector placed on the imaging surface; 1. A spectroscopic device for a two-dimensional object, comprising means for relatively moving a two-dimensional object placed in front of an input end. (4) At the input end, a plurality of highly directional optical element arrays are formed by bundling a plurality of highly directional optical elements in parallel in the row direction, which transmit only plane waves incident on the input end from a predetermined direction to the output end. The spectrometer according to claim 2 or 3 is separately arranged at the input end of a multi-beam high-directivity optical system stacked in the row direction and arranged in a matrix, and at the output end of each of the high-directivity optical element arrays. A two-dimensional object spectroscopy apparatus, characterized in that the two-dimensional object is arranged at an input end of the multi-beam highly directional optical system. (5) A plurality of highly directional optical element arrays, each consisting of a plurality of highly directional optical elements bundled in parallel in a column direction, which transmit only plane waves incident on the input end from a predetermined direction to the output end, are placed at the input end. The input end of a multi-beam high-directivity optical system stacked in the row direction and arranged in matrix form, and the multi-beam multi-beam arranged in a row with each output end of the highly directional optical element array paralleled in the column direction. The spectrometer according to claim 2 or 3 is arranged at the output end of the multi-beam high-directivity optical system, and the two-dimensional object is arranged at the input end of the multi-beam high-directivity optical system. A spectroscopic device for a two-dimensional object, characterized in that a two-dimensional object is arranged. (6) 2 at the front focal point of the condensing lens of the Michelson interference system
A two-dimensional photodetector is placed at the back focus of the imaging lens of the Michelson interference system, and when the movable mirror of the Michelson interference system is moved, the two-dimensional photodetector is 2, characterized in that a means is provided for Fourier-transforming each interferogram signal obtained from a plurality of predetermined sampling positions on the detection surface to obtain a spectrum of light from the position of the two-dimensional object corresponding to the sampling position.
Spectroscopic device for dimensional objects. (7) Instead of the condensing lens of the Michelson interference system, two or more highly directional optical elements are used to transmit only the plane wave that enters the input end from a predetermined direction to the output end and output it as a plane wave.
A two-dimensional multi-beam high-directivity optical system bundled in parallel in the dimensional direction is arranged, a two-dimensional object is arranged at the input end of the two-dimensional multi-beam high-directivity optical system, and a Michelson interference system is constructed. The imaging lens is omitted, and instead a two-dimensional photodetector is placed on the output side of the Michelson interference system, and when the movable mirror of the Michelson interference system is moved, the detection surface of the two-dimensional photodetector is A spectroscopic device for a two-dimensional object, comprising means for Fourier transforming each interferogram signal obtained from a plurality of sampling positions to obtain a spectrum of light from a position of the two-dimensional object corresponding to the sampling position. (8) A magnifying optical system that magnifies a plane wave emitted from a two-dimensional object in a predetermined direction and emits it as a plane wave, and the spectroscopic device according to any one of claims 1 to 7 is provided on the output side of the magnifying optical system. A two-dimensional microspectroscopy device characterized by: