JP2001027509A - Michelson interferometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a Michelson interferometer capable of exactly measuring with a simple constitution without light loss and forming a whole body thin, lightweight and inexpensive in production cost. SOLUTION: A Michelson interferometer 1 is constituted of a light incidence means 2, a first prism column A1, a second prism column B1, a light detection means 14 (13), a beam splitter 8, and a conversion means 5 (12) for converting diffused light to parallel light and parallel light to diffused light. The first prism column A1 has a light incidence plane 4, a conversion means 5, a first plane 7 and a second plane 6 provided side by side of the beam splitter 8. The second prism column B1 has a third plane 9 and a fourth plane 10 formed in the position facing the beam splitter 8 and a reflection curve 12 as a conversion means. The first prism column A1 and the second prism column B1 are constituted so as to arrange the first plane and the third plane side by side freely movably in light path length variation direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a spectroscope for performing precise measurement of an object to be measured by measuring an optical spectrum, and is used for Fourier transform spectroscopy suitable for spectral analysis of a sample and wavelength monitoring of optical communication. The present invention relates to a Michelson interferometer used as an interferometer or a moving distance measuring device, and more particularly to a Michelson interferometer used for obtaining an optical spectrum by Fourier spectroscopy from a change in interference intensity caused by a change in an optical path difference.

[0002]

2. Description of the Related Art Conventionally, a Fourier transform spectrometer using a Michelson interferometer to obtain a light spectrum performs a sample analysis or the like based on a detection result. A conventional Fourier transform spectroscope receives light from a light source into a Michelson interferometer or the like, and obtains an interferogram caused by an optical path length difference between an optical path branched into a variable optical path and a reference optical path by a beam splitter or the like, The spectrum of the light source is obtained by Fourier transforming the interferogram. In this method, the Michelson interferometer is the most important part. In particular, a Fourier transform infrared spectrometer used outdoors is required to be lightweight, small, environmentally resistant, and robust.
In remote monitoring, it is necessary to receive light from a sample via an optical fiber cable.

FIGS. 22A and 22B show an example of such a conventional Michelson interferometer. This is disclosed in U.S. Pat. No. 5,173,744, Refractive index scanning interferometer.
ive-ly Scanned Interferometer) '' Jens R. Dybwad (De
c.22,1992) is the outline of the configuration of the Michelson interferometer. 22 (a) and 22 (b), R1 is incident parallel light, R2 is outgoing parallel light, BS is a beam splitter surface, T is a transmission surface, L1 is a variable optical path, L2 is a reference optical path, P
Reference numeral 1 denotes a movable prism, P2 denotes a fixed prism, M1 denotes a plane mirror for a variable optical path, and M2 denotes a plane mirror for a reference optical path. Here, the operation of the conventional example shown in FIG. 22 will be described.

The incident parallel light R1 enters the movable prism P1 and is incident on the beam splitter surface BS. The light reflected by the beam splitter surface BS travels on the movable optical path L1,
The light is reflected by the plane mirror M1, travels again on the movable optical path L1, enters the beam splitter surface BS, passes through, and enters the fixed prism P2.

On the other hand, the incident parallel light R1 transmitted through the beam splitter surface BS enters the prism P2, travels on the reference optical path L2, is reflected by the plane mirror M2 for the reference optical path, travels the reference optical path L2 again, and then travels on the transmission surface T. Is reflected. At this time,
Light that has traveled along two paths, the variable optical path L1 and the reference optical path L2, is on the same optical axis and interferes with each other, so that a Michelson interferometer can be configured. To change the optical path length, as shown in FIG. 22B, the movable prism Pl and the fixed prism P2 are relatively moved.

At this time, assuming that the moving distance is d and the refractive index of the prism material is n, as shown in FIG.
Changes by d · sin θ, and the optical path length difference is 2n · d
・ Sin θ. Therefore, if a light source (not shown) is installed on the incident optical fiber bundle (not shown) of this interferometer, and a photodetector (not shown) is installed on the emitting optical fiber bundle (not shown). The interferogram, which is a change in light intensity with respect to the relative movement distance, can be measured, and the spectrum of the light source can be obtained by performing a Fourier transform on the interferogram. In this case, if the maximum moving distance is d _MAX , the wave number resolution is 1 / (2n · d _MAX
· Sin θ).

However, in the prior art shown in FIG. 22, since the optical axis of the light beam moves inside the prism, it is not possible to integrate the irradiation means for incident parallel light or the detection means for output parallel light with the main body of the interferometer. could not. For this reason, the optical axis needs to be adjusted, and since the optical path passes through the outside air,
There is a drawback that it is susceptible to changes in the external environment (such as changes in humidity). In order to overcome this drawback, the prior art shown as an example in the patent is shown in FIG.
(A) and (b). In FIG. 23 (a), F1 is an incident optical fiber bundle, F2 is an outgoing optical fiber bundle, and PM
1, PM2 is a plane mirror, CM1 and CM2 are curved mirrors, BS is a beam splitter surface, T is a transmission surface, and P1 is a plane mirror PM1.
, A curved mirror CM1 and a prism having the beam splitter surface BS as its constituent surfaces, and P2 a plane mirror PM2 and a curved mirror C
A prism composed of M2 and a transmission surface T.

Each of these prisms has an optical fiber bundle F
1, micromirror spots S1 and S2 provided on the surface where the prisms are closely arranged and for introducing and installing F1 and F2, and near the focal points of the curved mirrors CM1 and CM2; d is the relative movement distance of the prism, and θ is the inclination angle between the transmission surface T of the prism P2 and the plane mirror PM2. Here, the operation of the conventional example shown in FIG.

The light from the incident optical fiber bundle F1 passing through the pore B1 is reflected by the micromirror S1 while diverging, and then collimated by the curved mirror CM1 to become parallel light.
The light is incident on the beam splitter surface BS. The parallel light reflected by the beam splitter surface BS is reflected by the plane mirror PM1, enters the beam splitter surface again, passes through, and enters the prism P2. The parallel light is converted into convergent light by the curved mirror CM2, reflected by the micromirror S2, collected on the end face of the output optical fiber bundle F2, and extracted to the outside.

On the other hand, the parallel light transmitted through the beam splitter surface BS enters the prism P2, is reflected by the plane mirror PM2, is reflected by the transmission surface T, is incident on the curved mirror CM2, is converted into convergent light, and is converted into convergent light by the micro mirror S2. And is condensed on the end face of the output optical fiber bundle F2, and is extracted to the outside. As described above, the light that exits the optical fiber bundle F1 for incidence and travels along two paths reaches and interferes with the optical fiber F2 for emission, so that a Michelson interferometer can be configured. To change the optical path length, the prism P1 and the prism P2 are used.
Is relatively moved. Assuming that the moving distance at this time is d and the refractive index of the prism material is n, as shown in the figure, this position changes by d · sin θ, and the optical path length difference is 2n · d ·
sin θ.

Therefore, if a light source is installed on the incident optical fiber bundle of this interferometer and a photodetector is installed on the emitting optical fiber bundle, an interferogram which is a change in light intensity with respect to a relative moving distance can be measured. The spectrum of the light source can be obtained by performing a Fourier transform on the interferogram. In this case, assuming that the maximum moving distance is d _MAX , the wave number resolution is 1 / (2n · d _MAX · s).
inθ). According to the present invention, incident light and outgoing light are exchanged by an optical fiber, are hardly affected by an external environment change, and can be remotely measured.

[0012]

However, the conventional Michelson interferometer has the following problems. In the Michelson interferometer shown in FIG. 22, the difference in optical path length with respect to the maximum movement distance d _MAX is 2n · d _MAX · sin θ.
Can be scanned, but the wave number resolution increases as the optical path length difference increases. Therefore, in order to achieve high resolution, prism moving means capable of moving over a long distance is required, but the configuration of the conventional Michelson interferometer is large and expensive.

Further, the Michelson interferometer as shown in FIG. 23 overcomes the disadvantage that the interferometer could not be integrated with the parallel beam irradiation means or the output parallel light detection means in the prior art shown in FIG. Incoming light and outgoing light are exchanged by optical fibers, making it less susceptible to changes in the external environment, and enabling remote measurement. Due to partial blockage, a loss of about 10% was inevitable. Further, since the overlapping of the micromirrors blocking the optical path changes due to the relative movement of the prism, the loss greatly fluctuates, making it difficult to obtain an accurate interferogram.

Further, in the configuration shown in FIG. 22, since the optical axis changes with respect to the movement of the prism, if the movement distance is large, the change in the light-condensing position cannot be ignored and the detection efficiency decreases. In addition, the moving distance of the prism is limited, and consequently the wave number resolution is limited. Further, FIG.
In the configuration of 3, a deep pore almost penetrating the prism,
An operation for forming a micromirror was required, which increased the manufacturing cost. Furthermore, since the deep pore and the micromirror are installed inside the optical path, there is a limit to the thickness that can be manufactured.
In order to keep the ratio of shielding by micromirrors and pores low, the diameter of the beam in the vertical direction must be increased, and there is a limit to reducing the thickness of the prism.

Further, as in the prior art shown in FIG. 22, in the interferometer shown in FIG. 23, the optical path length difference can be scanned by 2n · d _MAX · sin θ with respect to the maximum moving distance d _MAX , but the wave number resolution is increased. Since the larger the optical path length difference, the higher the optical path length, the prism moving means that can move over a long distance is required to achieve high resolution, and this Michelson interferometer is large and expensive.

An object of the present invention has been made in view of the above points. An integrated Michelson interferometer can be formed by keeping the position of an output light beam constant. It is an object of the present invention to provide a small and inexpensive refractive index scanning Michelson interferometer that achieves high wavenumber resolution by increasing the optical path length difference change with respect to d. In addition, it eliminates the need to make micromirrors and pores, and eliminates the loss caused by the micromirrors and pores blocking the optical path and the change in the shielding ratio due to the relative movement of the prism. An object of the present invention is to provide a lossless, accurate, inexpensive, thin and lightweight refractive index scanning Michelson interferometer that achieves high wavenumber resolution by increasing the change distance.

[0017]

Means for Solving the Problems To solve the above problems,
The present invention provides a Michelson interferometer, comprising: a beam splitter that splits a light beam into reflected light and transmitted light; a first prism column; a second prism column; a light beam incident unit; a light detection unit; When the light is a diffused light, the diffused light is converted into parallel light, and when the light beam is a parallel light, the parallel light is converted into convergent light. And the first
A prism column, a light incident surface arranged at a position where the light incident means is installed, a first plane adjacent to the beam splitter and arranged on an optical path of light incident from the light incident surface; A second plane arranged to reflect light rays from the beam splitter in the direction of its optical path. Further, the second prism column is disposed along the first plane at a position facing the beam splitter, and is disposed so as to reflect light rays from the beam splitter in the direction of its optical path. And a light-emitting surface disposed at a position where the photodetector is installed. Also, the first from the light incident surface
The conversion means is provided in an optical path to a plane and one of the light beam incident means, and a reflection curved surface is provided in an optical path from the third plane to the light emission surface, further comprising the first prism and the second The prism column is relatively movable along the first plane and the third plane in the optical path length changing direction of the light beam.

With such a configuration, the light beam passing from the light beam incident means via the first prism column and the second prism column via the beam splitter can move the reference beam path and the variable beam by the relative movement of the two prisms. The light path can reach the detection means without light loss and without fluctuation. Also, on the output side of the light beam, a light beam obtained by converging the parallel light at a fixed position can always be reflected. The conversion means provided in the light beam incidence means may be a conversion lens.

Further, the Michelson interferometer includes a light beam incident means, a first prism column, a second prism column,
And light detecting means. The first prism column is formed adjacent to a light incident surface formed at a position connecting the light incident means, and the incident light from the light incident means is converted into parallel light. A first curved surface (converting means) that changes and reflects light; a first plane formed adjacent to the light incident surface and having a beam splitter for splitting the parallel light into transmitted light and reflected light; 1
A first surface is formed adjacent to a plane through a predetermined angle, and is formed adjacent to the first curved surface.
A second reflection plane (second plane) that reflects to the plane side. Further, the second prism column is formed adjacent to a third plane formed at a position facing the first plane through an internal angle of a predetermined angle with the third plane,
A fourth reflection plane (fourth plane) for reflecting the transmitted light to the third plane side, a light exit surface formed adjacent to the fourth reflection plane and connecting the light detection means, and a light exit surface A second curved surface (reflection curved surface) formed adjacent to the surface and adjacent to the third plane for converging the parallel light from the beam splitter side to the light detecting means. And a first plane of the first prism column;
It is good also as a structure which arrange | positions the 3rd plane of the said 2nd prism column body adjacently and is movable.

Further, the Michelson interferometer includes a light beam incidence means having a collimating lens (conversion lens),
It was composed of a prism column, a second prism column, and light detection means. The first prism column has a light incident surface formed at a position where the light incident means is arranged;
A first plane formed adjacent to the light incident surface and having a beam splitter for splitting parallel light from the light incident means into transmitted light and reflected light; A second reflection plane (second plane) that is formed adjacent to the first plane and reflects the reflected light toward the first plane side
And Further, the second prism column is formed adjacent to a third plane formed at a position facing the first plane via an inner angle of a predetermined angle with the third plane. A fourth reflecting light to the third plane side
A reflection plane (fourth plane), a light exit surface formed adjacent to the fourth reflection plane, and connecting the light detection means, adjacent to the light exit surface, and adjacent to the third plane. And a curved surface (reflection curved surface) for converging the parallel light from the beam splitter side to the light detecting means. Then, a first plane of the first prism column and a third plane of the second prism column may be arranged adjacent to each other and movably.

Further, the Michelson interferometer includes a beam splitter for splitting a light beam into reflected light and transmitted light, a first slab type waveguide plate, a second slab type waveguide plate, a light beam incident means, a light detecting device, Means for converting the diffused light into parallel light when the light is the diffused light, and converting the parallel light into convergent light when the light is the parallel light.
The first slab type waveguide plate is disposed on a light incident surface disposed at a position where the light incident means is installed, and adjacent to the beam splitter, and disposed on an optical path of light incident from the light incident surface. A first plane, and a second plane arranged to reflect light rays from the beam splitter in the direction of its optical path. Further, the second slab type waveguide plate has a third plane disposed at a position facing the beam splitter along the first plane, and reflects a light beam from the beam splitter in the direction of its optical path. And a light-emitting surface disposed at a position where the photodetector is disposed. Also,
In the optical path from the light incident surface to the first plane,
The conversion means is provided in at least one of the optical paths from the plane to the light emitting surface. The first slab type waveguide plate and the second slab type waveguide plate are respectively arranged along the first plane and the third plane,
It is relatively movable in the direction of changing the optical path length of the light beam.

With such a configuration, the light beam passing from the light beam incident means via the first slab type waveguide plate and the second slab type waveguide plate via the beam splitter is moved by relative movement of the two prisms. The reference means and the variable light path can reach the detecting means without loss of light and without fluctuation. Further, by adopting the waveguide structure as described above, it is possible to significantly reduce the thickness and weight as compared with the conventional method using a prism. And since a waveguide is usually manufactured using lithography technology, mass production is possible and it becomes cheap. In a Michelson interferometer using a slab type waveguide plate, it is convenient to provide the conversion means in either the light beam incidence means or the light detection means. The converting means of the light beam incident means and the light detecting means may be a converting lens.

When the thickness dimension of the Michelson interferometer is reduced, the Michelson interferometer is provided by the light beam incident means, the first slab type waveguide plate, the second slab type waveguide plate, and the light detection means. The meter was configured. And the first slab type waveguide plate is formed adjacent to the light incident surface and a light incident surface formed at a position connecting the light incident means,
A first curved surface (conversion unit) for reflecting incident light from the light beam incident unit as parallel light, and a beam formed adjacent to the light incident surface and for dividing the parallel light into transmitted light and reflected light A first plane having a splitter;
A first surface is formed adjacent to a plane through a predetermined angle, and is formed adjacent to the first curved surface.
A second reflection plane (second plane) that reflects to the plane side. Further, the second slab type waveguide plate is provided with the first slab type waveguide plate.
A third plane formed at a position facing the plane, and a fourth reflection formed adjacent to the third plane via a predetermined internal angle and reflecting the transmitted light toward the third plane; A plane (fourth plane), a light exit surface formed adjacent to the fourth reflection plane and connecting the light detecting means, and a light exit surface adjacent to the light exit surface and formed adjacent to the third plane. And a second curved surface (reflection curved surface) for converging the parallel light from the beam splitter side to the light detecting means. Then, the first plane of the first slab-type waveguide plate and the third plane of the second slab-type waveguide plate may be arranged so as to be movable adjacent to each other.

Further, the Michelson interferometer comprises a light beam incident means provided with a collimating lens (conversion lens), a first slab type waveguide plate, a second slab type waveguide plate, and a light detecting means. ing. The first slab type waveguide plate is formed adjacent to the light incident surface formed at a position where the light incident means is connected, and transmits the parallel light from the light incident surface. A first plane having a beam splitter for splitting the reflected light into light and reflected light, the first plane being adjacent to the first plane via an interior angle of a predetermined angle, and being formed adjacent to the light incident surface; A second reflection plane (a second plane) that reflects light toward the first plane is employed. Further, the second slab-type waveguide plate is formed adjacent to a third plane formed at a position facing the first plane via an internal angle of a predetermined angle with the third plane, A fourth reflection plane (fourth plane) for reflecting the transmitted light to the third plane side, a light exit surface formed adjacent to the fourth reflection plane and connecting the light detection means, and a light exit surface And a curved surface (reflection curved surface) formed adjacent to the surface and adjacent to the third plane for converging parallel light from the beam splitter side to the light detecting means. Then, the first plane of the first slab-type waveguide plate and the third plane of the second slab-type waveguide plate may be arranged so as to be movable adjacent to each other.

Further, the Michelson interferometer has a first prism column, a second prism column, a third prism column, a beam splitter for splitting a light beam into reflected light and transmitted light, and a refractive index matching. Index matching means, light beam incident means, and light detection means. The first prism column is a light incident surface disposed at a position where the light incident means is installed, and a second light incident surface adjacent to the beam splitter and disposed on an optical path of light incident from the light incident surface. It has one plane and a second plane arranged on the optical path of the light beam reflected by the beam splitter. Further, the second prism column is formed on a third plane disposed at a position facing the beam splitter along the first plane, and on a light path of a light beam transmitted through the beam splitter and the second plane. It has a fourth plane disposed on the extension, and a light emitting surface disposed at a position where the light detecting means is disposed.
Further, the third prism column includes a fifth plane disposed at a position facing the second plane of the first prism column and the fourth plane of the second prism column, and the first plane. A sixth plane disposed so as to reflect light rays transmitted through the second plane and the fifth plane from the third plane in the direction of the optical path, and the fourth plane and the fifth plane from the third plane. And a seventh plane arranged to reflect light rays transmitted through the optical path in the direction of the optical path. Further, the refractive index matching means is interposed between the second and fourth planes and the fifth plane.
The first prism column and the second prism column, and the third prism column are arranged along the second plane, the fourth plane, and the fifth plane to change the optical path length of the light beam. Is relatively movable.

With this configuration, by moving each prism column relatively in the direction of changing the optical path length of the light beam, both the sixth and seventh planes of the third prism column move, Since the optical path length difference of the light beam can be formed, the optical path length difference can be obtained twice as compared with the related art. Since there is no influence, the moving distance of the third prism column is not limited, and a high-resolution spectrum can be obtained.

The Michelson interferometer using the third prism column has at least one of an optical path from the light incident surface to the first plane and an optical path from the third plane to the light exit surface. It is convenient to provide, in the optical path, conversion means for converting the diffused light into parallel light when the light is diffused light and converting the parallel light into convergent light when the light is parallel light. Further, in the Michelson interferometer using the third prism column, the conversion unit may be provided in one of the light beam incidence unit and the light detection unit. The conversion means may be a conversion lens.

The Michelson interferometer includes a first slab type waveguide plate, a second slab type waveguide plate, a third slab type waveguide plate, and a beam splitter for splitting a light beam into reflected light and transmitted light. And a refractive index matching means for matching the refractive index, a light beam incident means, and a light detecting means. The first slab type waveguide plate is disposed on a light incident surface disposed at a position where the light incident means is installed, and is disposed on an optical path of a light incident from the light incident surface adjacent to the beam splitter. And a second plane disposed on an optical path of a light beam reflected by the beam splitter.
The second slab-type waveguide plate includes a third plane disposed at a position facing the beam splitter along the first plane, and a second plane on the optical path of a light beam transmitted through the beam splitter and the second plane. It has a fourth plane arranged on an extension of the plane, and a light emitting surface arranged at a position where the photodetector is installed. Further, the third slab type waveguide plate is a fifth plane disposed at a position facing the second plane of the first slab type waveguide plate and the fourth plane of the second slab type waveguide plate. And the second plane from the first plane.
A sixth plane arranged to reflect the light rays transmitted through the plane and the fifth plane in the direction of its optical path;
And a seventh plane arranged to reflect light rays transmitted from the third plane through the fourth and fifth planes in the direction of the optical path. The refractive index matching means includes a second plane, a fourth plane, and a fifth plane.
It is interposed between the planes. Further, the first slab type waveguide plate and the second slab type waveguide plate,
The slab-type waveguide plate is relatively movable along the second plane, the fourth plane, and the fifth plane in the direction of changing the optical path length of light rays.

With this configuration, the respective slab type waveguide plates are relatively moved in the direction of changing the optical path length of the light beam, so that both the sixth and seventh planes of the third slab type waveguide plate are moved. Move, and the optical path length difference of the light beam can be formed, so that the optical path length difference can be obtained twice as compared with the related art, and the optical axis does not change during the scanning of the third slab type waveguide plate. Since there is no effect on the light collection performance, the moving distance of the third slab type waveguide plate is not limited, and a high-resolution spectrum can be obtained. Further, by adopting such a waveguide structure, it is possible to significantly reduce the thickness and weight as compared with the conventional method using a prism. And since a waveguide is usually manufactured using lithography technology, mass production is possible and it becomes cheap.

The Michelson interferometer using the third slab type waveguide plate has at least one of an optical path from the light incident surface to the first plane and an optical path from the third plane to the light exit plane. It is convenient to provide, in the optical path, a conversion means for converting the diffused light into parallel light when the light is diffused, and converting the parallel light into converged light when the light is parallel. Furthermore, the conversion means may be provided in either the light beam incidence means or the light detection means. And
The conversion means of the light incident means and the light detection means,
It may be a conversion lens.

The conversion means provided in the optical path of the Michelson interferometer may be a reflection curved surface or a transmission curved surface. Further, the reflection curved surface and the transmission curved surface may be paraboloids, toroidal surfaces, spherical surfaces, or cylindrical surfaces.

It is to be noted that the phrase "each prism column or each slab type waveguide plate of the Michelson interferometer is relatively movable in the direction of changing the optical path length of the light beam" means that the first prism column is moved from the light beam incident means. Alternatively, the light beam incident on the first slab waveguide plate changes the optical path length between the variable optical path and the reference optical path, and moves the change in the interference intensity with respect to such optical path change in a direction that can be measured by the light detection means. Good,
Either one or the other or both sides of each prism column or each slab type waveguide plate may be moved.

The conversion lens refers to a collimating lens or a GRIN lens which is a gradient index lens, and includes a Fresnel zone plate (FZP).

[0034]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, a Michelson interferometer 1 includes a first prism column A ₁ and a second prism column B ₁ , an optical fiber 2 connected to the first prism column A ₁ as a light beam incident means, and and the connection part 3, as the conversion means and the connecting part 13 and the optical fiber 14 as a light detecting means connected to the second prism pillar B _1, which converts the diffused light to parallel light, converts the parallel light into convergent light Reflected curved surface (paraboloid of revolution 5 for collimation, paraboloid of revolution 1 for condensing)
2).

The first prism column A ₁ has an upper surface, a lower surface, and a peripheral side surface. The first prism column A ₁ has a light incident surface 4 formed on its peripheral side surface.
And a paraboloid of revolution 5 for collimation, which is a reflection curved surface (first curved surface) adjacent to the light incident surface 4, and a second reflection plane (second plane) adjacent to the paraboloid of revolution 5 for collimation.
6 and a first plane 7 which is adjacent to the second reflection plane 6 via an inner angle α ₁ of a predetermined angle θ and adjacent to the light incident surface 4. The first prism column A
The upper and lower surfaces of ₁ are not particularly limited in their shapes, but are formed so as to be parallel to each other in the drawings.

The light incident surface 4 is formed perpendicular to a horizontal plane as a reference, and the connecting part 3 is connected thereto. The position of the end face of the optical fiber 2 connected to the connection component 3 is
It is set to be the focal position of the collimating paraboloid of revolution 5. Paraboloid 5 for collimated incident light b ₁ diverging transmitted from the end face of the optical fiber 2, parallel light b ₂
A mirror surface is formed by means such as metal deposition so that the light is reflected toward the first plane 7.

Further, the second reflecting plane 6 has a parallel reflected light b
It is formed perpendicular to ₄ . Further, a mirror surface is formed on the second reflection plane 6 by means such as metal evaporation. When the second reflecting plane 6 is used as a reference plane, the first plane 7 is connected to the second reflecting plane 6 via an internal angle α ₁ formed at 45 °, which is an example here, as a predetermined angle θ. It is formed so as to have a 45-degree inclined surface to it. Further, the first plane 7, and a transmitted light b ₃ parallel light b _2, a beam splitter 8 for splitting the reflected light b _4.
The beam splitter 8 is formed by forming means such as vapor deposition of a thin film such as a metal and / or a dielectric.
It is formed on the first plane 7 so as to have predetermined transmittance and reflectance. The paraboloid of revolution 5 for collimation is
It is formed so as to ensure a sufficiently large reflection surface with respect to the irradiation range of the incident light b ₁ to be irradiated. First plane 7,
Light treatment of the beam splitter 8 and the second reflection plane 6 (division, transmission, reflection) surfaces are also formed so as to ensure a large enough for the parallel light b ₂ and the reflected light b ₄ sent I have.

On the other hand, the second prism pillar B ₁ represents, is constituted by upper and lower surfaces and the peripheral side surface. The second prism column B ₁ has a light exit surface 11 formed on a peripheral side surface thereof.
A condensing paraboloid of revolution 12 as a reflection curved surface (second curved surface) adjacent to the light exit surface 11; a third plane 9 adjacent to the condensing paraboloid of revolution 12; A fourth reflection plane (fourth plane) 10 is formed adjacent to the three planes 9 via one inner angle α ₂ of the predetermined angle θ and formed continuously (adjacent) to the light irradiation surface 11. . Here, the values of the internal angle α ₁ and the internal angle α ₂ are equal to each other and are the inclination angles θ.

The light exit surface 11 is opposite to a reference horizontal plane.
And the connection part 13 is formed vertically.
It is arranged at the position where it is connected. Connect to connection part 13
The position of the end face of the optical fiber 14 to be
It is set to be the focal position of the surface 12. Also,
The condensing paraboloid of revolution 12 is provided with means such as metal deposition.
A more mirror surface is formed. Further, the fourth reflection plane 10
Are formed on the same plane that is continuous with the light exit surface 11.
The mirror surface is formed by depositing metal, etc.
You. Then, the fourth reflection plane 10 is provided with a parallel transmitted light b.
_ThreeIt is formed so as to be perpendicular to. Also, the third plane
9 is a predetermined angle when the fourth reflection plane 10 is used as a reference plane.
Is formed at 45 degrees, which is an example here.
One interior angle α _TwoThrough 45 to the fourth reflecting plane 10
It is formed so as to have a degree inclined surface.

Next, the condensing paraboloid of revolution 12 is formed so that the parallel light b ₅ having a predetermined width in which the transmitted light b ₃ and the reflected light b ₄ are superimposed can be condensed on the end face of the optical fiber 14. Have been. Incidentally, transmitted light b _3, so as to ensure a sufficiently large reflection surface with respect to the irradiation range of the reflected light b ₄ and collimated light b _5, third plane 9, the parabolic for the fourth reflecting plane 10 and the condenser 12 are formed.

The first and second prism columns A ₁ , B ₁ configured as described above have a first plane 7 and a third
The plane 9 faces and is movably arranged in the optical path length changing direction. The phrase “the two prism columns A ₁ and B ₁ are movably disposed” means that the prism columns A ₁ and B ₁ are in a state of being close to each other with a gap, or a state in which the contact surface can slide and move. When the two prism columns A ₁ and B ₁ are relatively moved, the second prism column is moved here, and the moving mechanism is a known one using a linear guide or a precision feed mechanism. This is done by means.

Next, the operation of the Michelson interferometer 1 will be described with reference to FIGS. 1 and 2
As shown in (a), the incident light b from the optical fiber 2
₁ reaches the paraboloid of revolution 5 for collimation in a divergent state, and is collimated by the paraboloid of revolution 5 for parallel light b _2.
And is reflected to the beam splitter 8 side. In the beam splitter 8, parallel light b _2, is split into transmitted light b ₃ (variable optical path) and the reflected light b ₄ (Reference optical path).

The transmitted light b split by the beam splitter 8 and transmitted through the third plane 9 and incident on the second prism column B ₁
The light ₃ is reflected by the fourth reflection plane 10 and further reflected by one or both of the third plane 9 and the beam splitter 8, and reflected by the condensing rotary paraboloid 12. On the other hand, the reflected light b ₄ is reflected by the second reflection plane 6, passes through the beam splitter 8 and the third plane 9, and enters the second prism column B ₁ . Then, when the transmitted light b ₃ travels toward the condensing paraboloid of revolution 12, it overlaps with the reflected light b ₄ and reaches the condensing paraboloid of revolution 12 as parallel light b ₅ . The converging paraboloid of revolution 12 converges the parallel light b ₅ and causes the convergent light b ₆ to enter the end face of the optical fiber 14 connected to the light emitting surface 11 via the connecting part 13.

Next, as shown in FIG. 2 (b), is translated by a moving mechanism (not shown) in the direction of arrow a second prism pillar B ₁ by the movement distance d. At this time, the reflected light b ₄ split by the beam splitter 8 has the same optical path distance to the third plane 9 as the optical path distance before moving the second prism column B ₁ . On the other hand, the transmitted light b ₃ transmitted through the beam splitter 8 is transmitted to the fourth reflection plane 1.
0 to reach the third plane 9 is d · s
It is extended by inθ. Therefore, it is possible to measure the interference intensity by continuously changing the optical path.

As described above, the light beam emitted from the end face of the optical fiber 2 is not blocked at all in the optical path until it is emitted and enters the optical fiber 14, and the blocking ratio does not change. With these, an accurate interferogram can be measured. The second prism column B
Even ₁ moves, the focal point where the parallel light b ₅ incident light is collected from the paraboloid 12 for condensing light, the geometrical properties of the paraboloid of revolution, because it is always in the same position, Optical fiber 14
There is no loss of light rays incident on.

Here, the optical path length difference is 2nd · sin θ when the refractive index of the prism material is n, and the wave number resolution of Fourier transform spectroscopy is 1 / (2nd · sin).
θ). For example, using specific values, n = 1.
When 50, d = 0.3 cm, and θ = 45 degrees, the maximum optical path length difference is 0.64 cm. Therefore, the wave number resolution as Fourier transform spectroscopy is 1.6 cm ^-1 . If wavelength 1
When near-infrared light of 550 nm is used as irradiation light,
The wavelength resolution is 0.4 nm.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. As shown in Figure 3, a Michelson interferometer 1a includes a first prism pillar A ₂ and the second prism pillar B _2, connected to the first prism pillar A _2, the connecting parts 3a as the light incident means an optical fiber 2a with through a collimator lens 5a is a conversion means provided in the connection part 3a, the connection parts 13a and the optical fiber 14a as a light detecting means connected to the second prism pillar B ₂
And a reflection curved surface (a condensed rotation paraboloid 12a) as a conversion means for converting parallel light into convergent light.

First prism column A_TwoIs the top and bottom
And a peripheral side surface. And the first prism
Column A_TwoIs a light incident surface 4a formed on the peripheral side surface.
And a second reflection plane (the second reflection plane) adjacent to the light incident surface 4a.
Plane) 6a and this second reflection plane 6a
Interior angle β₁And adjacent to the light incident surface 4a
And a first flat surface 7a formed as described above. What
Contact, first prism column A _TwoThe top and bottom surfaces of the
It is not necessary to specify the shape of
It is formed to become.

The light incident surface 4a is formed perpendicular to a horizontal plane as a reference, and the connecting part 13a is connected to the light incident surface 4a. Further, the second reflection plane 6a is configured to output the parallel reflected light b _4.
Is formed vertically. Further, the second reflection plane 6
a is configured such that a metal or the like forms a reflecting surface by a forming means such as vapor deposition.

When the second reflecting plane 6a is used as a reference plane, the first plane 7a forms a predetermined angle, for example, an internal angle β ₁ formed at 45 degrees, which is an example here, through the second reflecting plane 6a. It is formed so as to have a 45 degree inclined surface with respect to 6a. In addition, this first plane 7a, has a transmitted light b ₃ parallel light b _2, a beam splitter 8a to divide the reflected light b _4. The beam splitter 8a is formed on the first plane 7a so as to have a predetermined transmittance and reflectance by depositing a thin film such as a metal and / or a dielectric. The first plane 7a, the light treatment of the beam splitter 8a and the second reflecting plane 6a (division, transmission, reflection) surfaces, so as to ensure a large enough for the parallel light b ₂ and the reflected light b ₄ Is formed.

Meanwhile, the second prism pillar B ₂ is constituted by upper and lower surfaces and the peripheral side surface. The second prism column B ₂ has a light exit surface 11 formed on a peripheral side surface thereof.
a, a condensing rotation paraboloid 12a as a reflection curved surface (curved surface) adjacent to the light exit surface 11a, a third plane 9a adjacent to the condensing rotation paraboloid 12a, and a third plane with adjacent via an internal angle beta ₂ of a predetermined angle θ to 9a, it is composed of a fourth reflecting plane (fourth plane) 10a consecutive (adjacent) to the light exit surface 11a. In addition,
Here, the values of the internal angle β ₁ and the internal angle β ₂ are equal and the predetermined angle θ
It is.

The light exit surface 11a is formed so as to be perpendicular to a horizontal plane serving as a reference.
a is arranged at a position to be connected. Connection part 13a
The position of the end face of the optical fiber 14a connected to the optical fiber 14a is set so as to be the focal position of the paraboloid 12a for condensing. In addition, the fourth reflection plane 10a is formed on the same plane that is continuous with the light emission surface 11a, and forms a mirror surface by depositing metal or the like. The condensing rotation paraboloid 12a also forms a mirror surface by depositing metal or the like. Then, the fourth reflection plane 10a is formed to be perpendicular to the parallel transmitted light b _3. Also,
The third plane 9a has a predetermined angle θ when the fourth reflection plane 10a is used as a reference plane.
Through the formed interior angle β ₂ , the fourth reflection plane 10
45 degrees with respect to a is formed such that (parallel light b 45 degrees with respect to ₅₎ the inclined surface of the. Note that the third plane 9a,
The light processing (division, transmission, reflection) surface of the condensing rotation paraboloid 12a and the fourth reflection plane 10a is composed of the transmitted light b ₃ and the reflected light b
_4, and it is formed so as to ensure a large enough for the parallel light b ₅ and convergent light b _6.

Next, the operation of the Michelson interferometer 1a will be described.
explain. As shown in FIG. 3 and FIG.
The light coming from the light source side is collimated by the optical fiber 2a.
Parallel light b through the lens 5a_TwoAnd the light incident surface
4a to the first prism A _TwoInto the beam splitter
Light (variable optical path) b_ThreeAnd reflected light (see
Light path) b_FourIs divided into Transmitted light b_ThreeIs the second prism
Pillar B_TwoThrough the third plane 9a and the fourth reflection plane 10a
Is reflected to the third plane 9a side by the third plane 9a and
One or both of the beam splitters 8a are used for focusing light.
The light is reflected toward the paraboloid surface 12a.

On the other hand, the reflected light b ₄ is reflected by the second reflecting plane 6a, passes through the first plane 7a, the beam splitter 8a and the third plane 9a, and proceeds to the side of the condensing rotary paraboloid 12a. Then, when passing through the third plane 9a, the transmitted light b ₃ and the reflected light b ₄ overlaps mate, parallel light b ₅
Collecting and reaches the light for rotational paraboloid 12a, it is incident on the end face of the optical fiber 14a as convergent light b ₆ is condensed by the parabolic 12a for the condenser as.

Next, from the position shown in FIG.
So that the second prism B _TwoThe moving mechanism (shown
The following is the result of parallel translation by
That is, the transmitted light b_ThreeIs the fourth reflection plane from the first plane 7a.
The distance to the surface 10a changes by d · sin θ, and the optical path length becomes
2n · d · sin θ increases. In response to such changes in the optical path,
Measurement of changes in interference intensity
Obtain the pherogram.

Note that the parallel light b ₅ is parallel to the center line of the paraboloid of revolution, so that
Converging point of the light incident on the end face of the optical fiber 34 is always the same, even if the second prism pillar B ₂ is moved always into the optical fiber 14a, the collected light is reached. In this way, all the optical paths from the fiber from which light is incident to the fiber which is emitted are not blocked at all, and the blocking rate does not change with the movement of the prism.

[0057] Then, Michelson interferometer 1a is, since the incident light enters as parallel light from the optical fiber 2a through the collimating lens 5a to the first prism pillar A _2, the installation position of the light incident means The optical axis adjustment such as searching for a focal point is not required. Therefore, the adjustment of the optical axis at the time of manufacture is necessary only when the light source and the photodetector are installed at the focal point of the parabolic mirror. Become.

Therefore, the optical axis adjustment is hardly necessary at the time of manufacture, and the optical axis adjustment after the start of use is not required at all. Therefore, the cost at the time of manufacture can be reduced, and the Michelson interferometer which is inexpensive and easy to use can be realized. . In the conversion means shown in FIGS. 1 to 4, the paraboloid of revolution has been described as an example of a reflection curved surface. However, a spherical surface configuration or a toroidal surface (horizontal curvature and vertical curvature are not considered) may be used. Even if it is configured as a different curved surface, it is possible to obtain parallel light and convergent light. Further, the beam splitters 8, 8a
Shows an example formed on the first planes 7 and 7a.
A configuration may be adopted in which a separate member is provided between the planes 7 and 7a and the third planes 9 and 9a, or a structure is provided on the third planes 9 and 9a.

Next, a third embodiment of the present invention will be described in detail with reference to FIGS. FIG. 5A is a plan view showing an arrangement of each prism of the Michelson interferometer according to the third embodiment of the present invention, and FIG. 5B is a plan view of the Michelson interferometer according to the third embodiment. FIG. 6 is a perspective view of each prism column, FIG. 6 is a plan view showing an operation state of the Michelson interferometer showing the third embodiment, and FIG. 7 (a) is a Michelson interferometer showing the third embodiment. FIG. 7B is a perspective view showing the entire Michelson interferometer showing the third embodiment.

[0060] As shown in FIGS. 5 and 7, a Michelson interferometer. 1b, reflecting the first prism pillar A _3, and the second prism pillar B _3, and the third prism pillar C _3, the light beam A beam splitter 8b for splitting light into transmitted light and a silicone oil 30 as a refractive index matching unit for matching the refractive index
b, an optical fiber 2b and a connecting part 3b as a light incident means, a connecting part 13b and an optical fiber 14b as a light detecting means, and a collimating lens (a converting lens) as a converting means disposed in the connecting parts 3b and 13b. )
5b and 12b.

As shown in FIG. 5 and FIG. 7, the first prism column A ₃ has an upper surface, a lower surface, and a peripheral side surface. The first prism column A ₃ is disposed on the peripheral side surface thereof, and the light incident surface 4b formed at the position of the optical fiber 2b connected via the connection component 3b, and the light from the light incident surface 4b And a second plane 6 formed on the optical path of the reflected light from the beam splitter 8b.
b. Further, the end surface (light irradiation surface) of the optical fiber 2b is provided at the focal position of the collimating lens 5b. Here, the shape of the first prism pillar A ₃ is a light incident surface 4b, a first plane 7b, are formed in a triangular prism body and a second plane 6b, In addition, the upper and lower surfaces of the shape Is described as a parallel plane in the drawings, but is not particularly limited.

[0062] As shown in FIGS. 5 and 7, the second prism pillar B ₃ is composed of upper and lower surfaces and the peripheral side surface. The second prism pillar B ₃ is disposed on the peripheral side surface, and a third plane 9b which is formed at a position facing the beam splitter 8b along the first plane 7b,
On the optical path of the transmitted light from the beam splitter 8b, and
A fourth plane 10b formed on the extension of the second plane 6b
And a beam exit surface 11b formed on the optical path of the beam transmitted from the beam splitter 8b and the third plane 9b. Further, the end surface (light incident surface) of the optical fiber 14b is provided at the focal position of the collimating lens 12b. Here, the shape of the second prism pillar A ₃ is a light output surface 11b, a third plane 9b, is formed in a triangular prism body consisting of a fourth plane 10b, also, the upper and lower surfaces of the shape Although it is described as a parallel plane in the drawings, there is no particular limitation.

[0063] As shown in FIGS. 5 and 7, the third prism pillar C ₃ is composed of upper and lower surfaces and the peripheral side surface. The third prism column C ₃ is disposed on the peripheral side surface, and is a fifth plane formed at a position facing the second plane 6 b and the fourth plane 10 b of the prism columns A ₃ and B ₃ . 21b, a sixth plane 22b formed at a position where light rays reflected from the beam splitter 8b and transmitted through the second plane 6b and the fifth plane 21b are reflected along the optical path, and transmitted through the beam splitter 8b. Then, the seventh light beam transmitted through the fourth plane 10b and the sixth plane 21b is formed at a position where the light ray is reflected along the optical path.
And a flat surface 23b. The sixth plane 22b
The seventh plane 23b is formed in a mirror-like shape that reflects light rays. The third prism pillar C ₃ is the fifth to seventh plane 21b in the drawings, 22b, are formed in a triangular prism body consisting 23b, In addition, although the parallel planes on upper and lower surfaces of the shape, the The shape and the shapes of the upper surface and the lower surface are not particularly limited.

As shown in FIGS. 5 and 7, silicone oil (refractive index matching liquid layer) 3
0b is provided between the first prism pillar and the second plane 6b and the second fourth plane 10b of the prism pillar B ₃ of A _3, third fifth plane 21b of the prism pillar C _3. The refractive index matching means includes prism prisms A ₃ , B ₃ , C
_As long as the prisms A ₃ , B ₃ , and C ₃ are formed of quartz, the silicone oil 30 may be used as an example.
The third prism column C ₃ and the first and second prism columns A ₃ and B ₃ are held by capillary action.

As shown in FIG. 5 to FIG.
The litter 8b is a first prism column A _ThreeFirst plane 6b of
And the second prism column B_ThreeAdhesion to the third plane 9b
Each prism column A is fixed by a material or the like._Three,
B_Three, C_ThreeDepending on the material of the
It is formed so that the excess ratio and the reflectance become a predetermined ratio.
I have. As an example of the beam splitter 8b, a metal
Intervening electrical conductors or both thin films,
Be sure to vapor-deposit on the transmission member (the same as each prism column)
It is formed. The first plane 7b or the third plane 7b
9b is deposited with a thin film of metal or dielectric or both
May be formed.

Next, the optical path of the light beam will be described. As shown in FIGS. 5 and 7, the light rays r ₁ of the diffused light from the optical fiber 2b, light (parallel light) r ₂ incident as parallel light by the collimator lens 5b are incident on the beam splitter 8b. The light beam r ₃ split and transmitted by the beam splitter 8 b is
b, after being incident on the fifth plane 21b, the seventh plane 23b
And is transmitted through the silicone oil 30b again to the beam splitter 8b. On the other hand, beam splitter 8
The light beam r ₄ split and reflected by the second b passes through the second plane 6b, the silicone oil 30b, and the fifth plane 21b, is reflected by the sixth plane, and again passes through the silicone oil 30b and the like along the optical path. To the beam splitter 8b. The light beams r ₃ and r ₄ sent to the beam splitter 8b side are combined and interfere with each other, and are converged as a light beam (parallel light) r ₅ by the collimating lens 12b on the light emitting surface 11b. made incident on the optical fiber 14b as r _6.

Next, the operation of the present invention will be described with reference to FIG. The first and second prism columns A ₃ , B
_{In the} case where the third prism column C ₃ is relatively moved, the third prism column C ₃ is moved here.
The moving mechanism is performed by a known means using a linear guide, a precision feeding mechanism, or the like. Third prism column C
₃ in the optical path length changing direction by a distance d consider the case where moved linearly. At this time, the silicone oil 30b (refractive index matching liquid layer) is sandwiched between narrow gaps between the first and second prism columns A ₃ and B ₃ and the third prism column C _{3 and} is held by capillary action. I have. The distance traveled by the light beam r ₃ transmitted through the beam splitter before being reflected by the seventh plane 23b increases by d · sin θ, and the light beam r ₄ reflected by the beam splitter 8b is reflected by the sixth plane 22b. Is reduced by d · sin θ. Therefore, the change in the distance traveled by the light is increased by 2 dsin θ and 2
d · sin θ decreases, and assuming that the refractive index of the third prism column C ₃ is n and the maximum movement distance is d _MAX , the maximum optical path length difference in this optical path is 4n · d _MAX · sin θ.

This is because the wave number resolution is 2 compared to the prior art.
This is equivalent to a twofold improvement. Here, for example, when a specific value is used, the refractive index n of the material of the prism 8b is 1.5.
0, maximum moving distance d = 0.3 cm, θ = 45 degrees,
The maximum optical path length difference d _MAX is 1.3 cm, and the wave number resolution as a Fourier transform spectrometer is 0.8 cm ⁻¹ . For example, when near-infrared light having a wavelength of 1550 nm is used,
The wavelength resolution is 0.2 nm.

The direction of forming the incident light of the light beam used in FIGS. 5 to 7 is not limited to any particular means such as a lens system and a mirror system. Input and output are performed by the optical fiber with the lens, and the optical path in the interferometer does not pass through free space at all, so that it is not affected at all by the external environment change (such as humidity change). In addition, since the optical path is not interrupted by the optical component, which is a disadvantage of the related art, an accurate measurement value can be obtained.

Next, as shown in FIGS. 8A and 8B,
A fourth embodiment according to the present invention will be described. FIG. 8 (a),
As shown in (b), the Michelson interferometer 1c has a first
A prism column A ₄ , a second prism column B ₄ , a third prism column C ₄ , a beam splitter 8 c for dividing a light beam into reflected light and transmitted light, and a refractive index matching unit for matching a refractive index. A silicone oil 30c, an optical fiber 2c and a connecting part 3c as light beam incident means, a connecting part 13c and an optical fiber 14c as light detecting means,
Reflection curved surfaces 5c and 12c are provided as conversion means for converting the diffused light into parallel light and the parallel light into convergent light.

The first prism column A ₄ has an upper surface, a lower surface, and a peripheral side surface. Then, the first prism column A ₄ is disposed on the peripheral side surface thereof, and the connecting member 3 c
A light incident surface 4c formed at the position of the optical fiber 2c connected via the optical fiber 2c, a reflection curved surface (a paraboloid of revolution for collimation) 5c formed on the optical path of the light incident from the light incident surface 4c. A first plane 7c formed on the optical path of the light beam from the reflection curved surface 5c, and a second plane 6c formed on the optical path of the reflected light from the beam splitter 8c provided adjacent to the first plane 7c. And The end surface (light irradiation surface) of the optical fiber 2c is arranged so as to be at the focal position of the reflection curved surface 5c. The first prism pillar A ₄ has its upper and lower surfaces are shown in a horizontal plane in the drawing, but the invention is not particularly limited.

On the other hand, the second prism column B ₄ has an upper surface, a lower surface, and a peripheral side surface. The second prism pillar B ₄ is a fourth plane 10c formed in the third plane 9c formed on opposing positions of the beam splitter 8c, the optical path of the light beam transmitted through the beam splitter 8c
A reflection curved surface 12c formed on the optical path transmitted from the beam splitter 8 and the third plane 9c side; and a reflection curved surface 12c disposed on the optical path of the convergent light transmitted from the reflection curved surface 12c. And a light exit surface 11c formed at the installation position of the fiber 14c. Also,
The end surface (light incident surface) of the optical fiber 14c is
It is set to be at the focal position of c. The first
Prism pillar B ₄ has its upper and lower surfaces are shown in a horizontal plane in the drawing, but the invention is not particularly limited.

Further, the third prism column C ₄ has an upper surface, a lower surface, and a peripheral side surface. And
Third prism pillar C ₄ is disposed on the peripheral side surface, the two prism pillar A _4, the second plane 6c and the fourth fifth plane 21c which is formed at a position facing to the plane 10c of the B ₄
And the second plane 6 reflected from the beam splitter 8c.
c and a sixth plane 22c formed at a position where light rays passing through the fifth plane 21c are reflected along the optical path;
A seventh plane 23c is formed at a position where light rays transmitted through the beam splitter 8c and transmitted through the fourth plane 10c and the sixth plane 21c are reflected along the optical path. The sixth plane 22c and the seventh plane 23
c is formed in a mirror-like shape that reflects light rays. The third prism column C ₄ is connected to the fifth to seventh prisms in the drawing.
It is formed in a triangular prism composed of the planes 21c, 22c, and 23c, and the upper and lower surfaces are parallel planes. However, the shape and the upper and lower surfaces are not particularly limited.

As shown in FIGS. 8A and 8B, the refractive index
Silicone oil (refractive index matching liquid)
Layer) 30c is the first prism column A_FourOf the second plane 6c
And second prism column B_FourOf the fourth plane 10c and the third
Rhythm column C_FourIs provided between the fifth planes 21c.
You. Then, the refractive index matching means is provided for each prism A_Four,
B _Four, C_FourThe refractive index of the member forming
As an example, each prism A_Four, B_Four,
C_FourIs formed of quartz, silicone oil 30c
Is used, and it is structured so that it is retained by capillary action.
Has been established.

[0075] FIG. 8 (a), the as shown in (b), the beam splitter 8c is the first prism pillar A ₄ first plane 6
and c, are fixed by an adhesive or the like between the third plane 9c of the second prism pillar B _4, each prism pillar A _4, B
_4, the material and C _4, and is configured so that transmittance and reflectance becomes a predetermined ratio by angles sent come rays. As an example of the beam splitter 8c, the beam splitter 8c is formed by interposing a thin film such as a metal and / or a dielectric, or by vapor deposition on a transmission member (having the same quality as each prism column). Note that the beam splitter 8c
A thin film such as a metal and / or a dielectric may be formed on the first plane 7c or the third plane 9c by thin film forming means such as vapor deposition.

Next, the optical path of the light beam will be described. Figure
8 (a) and 8 (b), the optical fiber 2c
Light rays r incident from the light incident surface 4c as diffused light₁Is
The ray r is converted into parallel light by the reflection curved surface 5c and reflected.
_TwoIs incident on the beam splitter 8c. And
Light beam r split and transmitted by the beam splitter 8c _Three
Penetrates the fourth plane 10c and the silicone oil 30c.
After passing through and entering the fifth plane 21c, the light is reflected by the seventh plane 23c.
Silicone oil along the transmitted light path
The light passes through 30c and goes to the beam splitter 8c.

On the other hand, the beam splitter 8c
The ray of light r_FourIs the second plane 6c, silicone oil
30c, the light passes through the fifth plane 21c, and is deflected by the sixth plane.
Irradiates the silicone oil 30c again along its optical path.
And the like to the beam splitter 8c. And
Light beam r sent to the beam splitter 8c side_Three, R _Four
Is deflected by the beam splitter 8c and the third plane.
Are emitted, combined and interfere with each other_FiveAs reflection
The light enters the curved surface 12c. Furthermore, by the reflection curved surface 12c
Ray r which is a parallel light_FiveIs transformed and converged to the ray r₆
The light detecting means (the connecting part 13,
This is output to the optical fiber 14).

The operation of the present invention is the same as that of the third embodiment shown in FIG. 6, and the wave number resolution is twice as high as that of the prior art. In the fourth embodiment, the optical fibers 2c and 14c are connected to the Michelson interferometer by the connecting component 3.
c, 13c by which carried human output to the prism pillar A _4, B _4, receives no influence of the external environmental change (humidity change and the like) for the optical path does not pass through the free space in exactly the interferometer in. In addition, since the optical path is not interrupted by the optical component, which is a disadvantage of the related art, an accurate measurement value can be obtained.

Next, the fifth embodiment will be described with reference to FIG.
This is shown with reference to FIG. FIG. 9 (a), the as shown in (b), a Michelson interferometer. 1d, first prism pillar A ₅
, A second prism column B _5, and a third prism column C
₅ , a beam splitter 8d for splitting a light beam into reflected light and transmitted light, a silicone oil 30d as a refractive index matching means for matching a refractive index, an optical fiber 2d and a connecting part 3d as a light incident means, A connecting part 13d and an optical fiber 14d are provided as means, and transmission curved surfaces 5d and 12d are provided as converting means for converting diffused light into parallel light and converting parallel light into convergent light.

[0080] The first prism pillar A ₅ are, is composed of upper and lower surfaces and the peripheral side surface. The first prism pillar A ₅ are, disposed on the peripheral side surface, connecting member 3d
A light incident surface 4d formed at the position of the optical fiber 2d installed through the light transmitting surface, a transmission curved surface 5d formed on the light incident surface 4d, and transmitting the diffused light from the optical fiber 2d as parallel light; It has a first plane 7d formed on the optical path of the light beam from the curved surface 5d, and a second plane 6d formed on the optical path of the reflected light from the beam splitter 8d provided adjacent to the first plane 7d. are doing. further,
The end surface (light irradiation end surface) of the optical fiber 2d is a transmission curved surface 5d.
It is installed so that it may become the focal position. The first prism pillar A ₅ represents, its upper and lower surfaces are shown in a horizontal plane in the drawing, but the invention is not particularly limited.

On the other hand, as shown in FIGS. 9A and 9B,
The second prism pillar B ₅ is composed of upper and lower surfaces and the peripheral side surface. And the second prism column B ₅
Are transmitted from the third plane 9d formed at the position facing the beam splitter 8d, the fourth plane 10d formed on the optical path of the light beam passing through the beam splitter 8d, and the beam splitter 8 and the third plane 9d. It has a light exit surface 11d formed at the position where the optical fiber 14d is disposed on the incoming optical path and installed via the connection component 13d, and a transmission curved surface 12d formed on the light exit surface 11d. I have. Further, the end surface (light incident surface) of the optical fiber 14d is set so as to be at the focal position of the transmission curved surface 12d. The first prism pillar B ₅ has its upper and lower surfaces are shown in a horizontal plane in the drawing, but the invention is not particularly limited.

[0082] Further, the third prism pillar C ₅ is composed of upper and lower surfaces and the peripheral side surface. And
Third prism pillar C ₅ is disposed on the peripheral side surface, the two prism pillar A _5, second plane 6d and fifth plane 21d which is formed at a position facing the fourth plane 10d of B ₅
And the second plane 6 reflected from the beam splitter 8d.
d and a sixth plane 22d formed at a position to reflect the light beam transmitted through the fifth plane 21d along the optical path;
A seventh plane 23d is formed at a position where light rays transmitted through the beam splitter 8d and transmitted through the fourth plane 10d and the sixth plane 22d are reflected along the optical path. The sixth plane 22d and the seventh plane 23
d is formed in a mirror-like shape that reflects light rays. In the drawing, the third prism column C ₅ is connected to the fifth to seventh prisms.
It is formed in a triangular prism body composed of planes 21d, 22d and 23d, and the upper and lower surfaces are parallel planes. However, the shape and the upper and lower surfaces are not particularly limited.

As shown in FIGS. 9A and 9B, the refractive index
Silicone oil (refractive index matching liquid)
Layer) 30d is the first prism column A_FiveOf the second plane 6d
And second prism column B_FiveOf the fourth plane 10d
Rhythm column C_FiveIs provided between the fifth planes 21d.
You. Then, the refractive index matching means is provided for each prism A_Five,
B _Five, C_FiveAre also similar in refractive index.
As an example, each prism A_Five, B_Five,
C_FiveIs formed of quartz, silicone oil 30d
Is used, and it is structured so that it is retained by capillary action.
Has been established.

[0084] FIG. 9 (a), the as shown in (b), the beam splitter. 8d, the first prism pillar A ₅ first plane 6
d and are fixed by an adhesive or the like between the second third plane 9d of the prism pillar B _5, each prism pillar A _5, B
_5, the material and the C _5, and is configured such that the transmittance and reflectance at a predetermined ratio by angles sent come rays. As an example of the beam splitter 8d, the beam splitter 8d is formed by interposing a thin film such as a metal and / or a dielectric, or by vapor deposition on a transmission member (having the same quality as a prism column). Note that a thin film such as a metal and / or a dielectric may be formed by vapor deposition on the first plane 7d or the third plane 9d.

Next, the optical path of the light beam will be described. As shown in FIG. 9 (a), the light rays r ₁ which is irradiated as diffused light from the optical fiber 2d is converted into parallel rays r ₂ through the transmission curved 5d are incident on the beam splitter 8d. Then, split by the beam splitter 8d, transmitted light and becomes light (parallel light) r ₃ after entering the fifth plane 21d through the fourth plane 10d and silicone oils 30d, is reflected by the seventh plane 23d again The light passes through the silicone oil 30d and the like and goes to the beam splitter 8d.

On the other hand, the light ray (parallel light) r ₄ split and reflected by the beam splitter 8d passes through the second plane 6d, the silicone oil 30d, and the fifth plane 21d, is reflected by the sixth plane, and travels along its optical path. Again passes through the silicone oil 30d and the like to the beam splitter 8d. The transmitted light rays r ₃ and r ₄ are reflected by the beam splitter 8 d and the third plane 9 d and are combined and interfere with each other, and are formed as a parallel light ray r ₅ on the light emission surface 11 d as a transmission curved surface. It is sent to 12d. Then, the light ray r ₆ converged when transmitting through the transmission curved surface 12 d is output to the light detection means (the optical fiber 14 fixed by the connection component 13).

The operation of the present invention is similar to that of the third embodiment shown in FIG.
The wave number resolution is twice as high as that of the conventional technology.
I have. In the fourth embodiment, the Michelson interference
The optical fibers 2c and 14c are connected to the connecting parts 3c and 1
Each prism column A by 3c _Four, B_FourOutput to human
And the optical path in the interferometer does not pass through free space at all.
Not affected by changes in the external environment (such as changes in humidity). Ma
Also, the disadvantage of the prior art 2 is that the optical path
Since no interruption occurs, an accurate measurement value can be obtained.

Next, a sixth embodiment of the present invention will be described with reference to FIG.
This will be described with reference to (a) and (b). Michelson interference
1A is a first slab type waveguide plate as shown in FIG.
1A ₁And second slab type waveguide plate 1B₁And the first sla
Waveguide plate 1A₁Light as a beam incident means connected to
Fiber 2e and connecting part 3e, second slab type waveguide
Road board 1B₁Connecting part 13 as light detecting means connected to
e and the optical fiber 14e.

The first and second slab type waveguide plates 1A ₁ ,
1B ₁ has a core layer e _2, the upper clad layer e ₁ provided on the upper surface of the core layer e _2, and a lower cladding layer e ₃ Metropolitan provided on the lower surface of the core layer e _2.

Then, the first slab type waveguide plate 1A ₁
And the light incident surface 4e of the connection piece 3e formed on the peripheral side surface is connected, is formed adjacent to the light incident surface 4e, changing means for reflecting the incident light c ₁ as parallel light c ₂ (first A reflection curved surface (parabolic surface for collimation) 5e as a curved surface, a second reflection plane (second plane) 6e formed adjacent to the paraboloid for collimation 5e, and a predetermined reflection surface on the second reflection plane 6e with adjacent via an interior angle alpha ₁ of the angle theta, it is formed adjacent to the light incident surface 4e, a parallel light c
It is composed of a first plane 7e having a beam splitter 8e dividing ₂ into transmitted light c ₃ and the reflected light c _4.

[0091] On the other hand, the second slab waveguide plate 1B ₁ includes a light exit surface 11e formed on its circumferential surface, the reflection curved surface (collector as converting means adjacent to the light exit surface 11e (the second curved surface) Parabolic surface for light) 12e and parabolic surface for condensing 1
Adjacent to 2e, and a third plane 9e is disposed at the position facing the beam splitter 8e, together with the adjacent via an internal angle alpha ₂ of the predetermined angle θ to the third plane 9e, light exit surface 1
4th reflection plane (fourth plane) 10 continuous (adjacent to) 1e
e.

Incidentally, both slab type waveguide plates 1A₁, 1B₁
Irradiation from end face of optical fiber 2e
Incident light c₁(Incident light b₁) From convergent light c₆(convergence
Light b ₆1) and FIG.
Except that the thickness is different from that of the configuration shown
Description is omitted. Further, the slab type waveguide is a core layer e. _Two
Means an optical path along which planar light can travel. further,
Incident light c₁Convergent light c₆Light treatment at each position up to
Split, transmissive, reflective) surface is sufficient for the width of light in the horizontal direction
It has a large light treatment surface.

Next, the operation of the Michelson interferometer 1A will be described. Is moved by the movement distance d by the second slab waveguide plate 1B ₁ a moving mechanism (not shown), the optical path length of the transmitted light c ₃ divided by the beam splitter 48 to 2
n · d · sin θ (FIG. 2)
(See (a) and (b)). Then, a state of fixing the second slab waveguide plate 1B _1, if the incident light in a state that has moved is detected via the slab waveguide parallel light c ₅ parabolic 12e for condensing because it is parallel to the center line, the geometrical properties of the parabola (surface), the focal point of the convergent light c ₆ incident on the end face of the optical fiber 14e is always that focused at the same position (FIG. 2 (See (a) and (b)). Therefore, an accurate interferogram can be measured.

The specific configuration of the Michelson interferometer 1A is shown below. First and second slab type waveguide plates 1
When A ₁ and 1B ₁ are made of a quartz material, the core layer e ₂ is 8 μm, the upper cladding layer e ₁ is 15 μm, the lower cladding layer e ₃ is 20 μm, and the combined thickness is 5 μm.
0 μm or less. At this time, the wavelength of the incident light uses near infrared rays (1550 nm or the like as an example). Note that the slab waveguide can be manufactured using lithography technology, so that mass production is possible.

Next, the seventh embodiment will be described with reference to FIGS.
This will be described with reference to FIG. Michelson interferometer 2A
Is a first slab type waveguide plate 1A as shown in FIG. _Two
And second slab type waveguide plate 1A_TwoAnd the first slab type
Wave board 1A_TwoCollimator as a beam incident means connected to
Optical fiber provided with a lens 5f for connection via a connecting part 3f.
Bar 2f and second slab type waveguide plate 1B_TwoOptical detector connected to
Connecting component 13f and optical fiber 14f as output means
And

The first and second slab type waveguide plates 1A ₂ ,
1B ₂ includes a core layer f _2, the upper clad layer f ₁ provided on the upper surface of the core layer f _2, and a lower cladding layer f ₃ Metropolitan provided on the lower surface of the core layer f _2.

Then, the first slab type waveguide plate 1A ₂
A light incident surface 4f formed on the peripheral side surface to which the connecting component 3f is connected, and a first flat surface 7f disposed adjacent to the light incident surface 4f and formed in the optical path of the incident light beam.
And a beam splitter 8f provided on the first plane 7f.
And a light ray c ₄ reflected from the beam splitter 8f.
And a second flat surface 6f formed on the optical path of the second light source. Incidentally, the first plane 7f are adjacent via an internal angle beta ₁ of a predetermined angle θ in the second plane 6f.

[0098] On the other hand, the second slab waveguide plate 1B ₂ includes a light exit surface 11f formed on its circumferential surface, as a conversion means for converting the convergent light parallel light adjacent to the light exit surface 11f (curved) A reflection curved surface (a parabolic surface for light collection) 12f;
A third plane 9f formed at a position adjacent to the concentrating paraboloid 12f and facing the beam splitter 8f, adjacent to the third plane 9f via an inner angle β ₂ of a predetermined angle θ, and , A fourth reflection plane (fourth plane) 10f formed continuously (adjacent) to the light exit surface 71.

Incidentally, both slab type waveguide plates 1A ₂ , 1B ₂
From the parallel light c ₂ (parallel light b ₂ ) to the convergent light c ₆ (convergent light b ₆ ) which are irradiated from the end face of the optical fiber 62 and are incident in parallel by the collimating lens 5f. The optical path through which the light travels is the same as that of the configuration shown in FIGS. In addition, the slab type waveguide, say an optical path that may progress planar light along the core layer f _2. The slab waveguide is manufactured using lithography technology. The optical processing of each position from the parallel light c ₂ to convergent light c ₆ (division, transmission, reflection) surfaces is provided with a large light treatment surface with respect to sufficient horizontal direction of the light width.

Next, the operation of the Michelson interferometer 2A will be described with reference to FIG. 2nd slab type waveguide plate 1B ₂
Is moved by a moving distance d by a moving mechanism (not shown), the transmitted light c split by the beam splitter 8f
The optical path length of No. ₃ can be changed by 2n · d · sin θ (see FIGS. 4A and 4B). Then, a state of fixing the second slab waveguide plate 1B _2, if the light incident in a mobile state is detected through the slab waveguide,
Since parallel light c ₅ is parallel to the center line of the parabolic 12f for condensing, the geometrical properties of the parabola (surface), the focal point of the convergent light c ₆ incident on the end face of the optical fiber 14f is You will always focus on the same position. Therefore, an accurate interferogram can be measured.

[0102] Incidentally, Michelson interferometer. 2A, since the incident light enters as parallel light from the optical fiber 2f through the collimating lens 5f to the first slab waveguide plate 1A _2, installation of the light incident means The position is arbitrary, and there is no need for troublesome optical axis adjustment such as searching for a focal point. Therefore, the adjustment of the optical axis at the time of manufacture is necessary only when the light source and the photodetector are installed at the focal point of the parabolic mirror.
The adjustment is not required twice unless it deviates. Therefore, the optical axis adjustment is hardly required at the time of manufacture, and the optical axis adjustment after the start of use is not required at all. Therefore, the cost at the time of manufacture can be reduced, and the Michelson interferometer which is inexpensive and easy to use can be realized.

Further, the first type shown in FIGS.
Although the reflection curved surfaces of the second slab type waveguide plates 1A ₁ , 1B ₁ , 1B ₂ have been described as paraboloids, parallel light and convergent light can be obtained even with a cylindrical surface.

Next, FIGS. 12A and 12B and FIG.
An eighth embodiment of the present invention will be described with reference to FIG.
As shown in FIGS. 12A, 12B and 13, the Michelson interferometer 3A includes a first slab type waveguide plate 1A.
_3, a second slab waveguide plate 1B _3, a third slab waveguide plate 1C _3, a beam splitter 8g to split the light into reflected light and transmitted light, the refractive index matching means for matching the refractive index 30 g of silicone oil, an optical fiber 2 g and a connecting part 3 g as a light incident means, a connecting part 13 g and an optical fiber 14 g as a light detecting means, and arranged in the connecting parts 3 g and 13 g to convert the diffused light into parallel light. ,
Further, it has collimating lenses (conversion lenses) 5g and 12g as conversion means for converting parallel light into convergent light.

As shown in FIGS. 12A and 12B and FIG. 13, the first and second slab type waveguide plates 1A ₃ and 1B
₃ is a core layer g ₂ , an upper clad layer g ₁ and a lower clad layer g ₃ provided on the upper and lower surfaces of the core layer g _2.
It is composed of The first slab waveguide plate 1A ₃ is disposed on the peripheral side surface, and the light incident surface 4g formed at positions to install the optical fiber 2g via the connection part 3g, from the light incident surface 4g First plane 7g formed on the optical path of the light beam and adjacent to beam splitter 8g
And a second plane 6b formed on the optical path of the reflected light from the beam splitter 8g. Further, the end surface (light irradiation surface) of the optical fiber 2g is provided at the focal position of the collimating lens 5g.

[0105] FIG. 12 (a), the as shown in (b) and 13, the second slab waveguide plate B _3, the beam splitter 8 is disposed on the peripheral side surface, along said first plane 7g
g, a fourth plane 10g formed on the optical path of the transmitted light from the beam splitter 8g, and an extension of the second plane, a beam splitter 8g, It has a light emitting surface 11g that is arranged on the optical path of the light beam sent from the three planes and is formed at a position where the optical fiber 2g is installed via the connection component. The end face (light incident face) of the optical fiber 14g is
It is installed at the focal position of the collimating lens 12g.

FIGS. 12A and 12B and FIG.
As described above, the third slab type waveguide plate 1C _ThreeOn the peripheral side
Disposed, the two slab type waveguide plates 1A_Three, 1B_ThreeNo.
Formed at a position facing the second plane 6g and the fourth plane 10g
The fifth plane 21g formed and the beam splitter 8g
Reflected from the second plane 6g and the fifth plane 21g
Is formed at a position where the incoming light ray is reflected along its optical path.
Through the sixth plane 22g and the beam splitter 8g.
Passing through the fourth plane 10g and the sixth plane 21g
Formed at a location that reflects incoming light rays along its path
And a seventh plane 23g. The sixth plane 2
2b and the seventh plane 23b are mirror-like reflecting light rays.
Is formed.

[0107] As shown in FIGS. 12 and 13, silicone oil (refractive index matching liquid layer) of the refractive index matching means 30g, the second plane 6g and a second slab of the first slab waveguide plate 1A ₃ the fourth plane 10 of the waveguide plate 1B ₃
and g, is provided between the third fifth plane 21g of the slab type waveguide plate 1C _3. The refractive index matching means may be any member as long as the members forming the slab type waveguide plates 1A ₃ , 1B ₃ , 1C ₃ have similar refractive indexes. As an example, each slab type waveguide plate 1A ₃ , 1B ₃ , 1C ₃ made of quartz, 30 g of silicone oil is used here, and the third slab type waveguide plate 1C ₃ and the first and second slab type waveguide plates 1A ₃ , 1B ₃ are configured to be held by capillary action.

[0108] As shown in FIGS. 12 and 13, the beam splitter 8g, the first of the first slab waveguide plate 1A ₃
The plane 6 g, of the second slab waveguide plate 1B ₃ third plane 9
g, and is fixed by an adhesive or the like, and the transmittance and the reflectance are set to a predetermined ratio depending on the material of each slab type waveguide plate 1A ₃ , 1B ₃ , 1C ₃ and the angle of the transmitted light beam. It is formed so that it becomes. As an example of the beam splitter 8g, a metal and / or a dielectric thin film may be interposed, or a transmission member (same as each slab type waveguide plate)
It is formed so as to be vapor-deposited. The first plane 7
g or the third plane 9g may be formed by depositing a thin film such as a metal and / or a dielectric.

Next, the optical path of a light ray will be described. As shown in FIGS. 12A and 13, the optical fiber 2 g
Rays r ₁ of the diffused light from the incident from the light incident surface 4g as are light rays (parallel light) r ₂ into parallel light by the collimator lens 5b. And the incident light beam r ₂ is
The light is split into a light beam r ₃ (transmitted light) that is incident on and transmitted by the beam splitter 8b and a light beam r ₄ (reflected light) that is reflected. The light beam r ₃ split and transmitted by the beam splitter 8g passes through the silicone oil 30b and is incident on the fifth plane 21g. Then, the light ray r ₃ is reflected on the seventh plane 23g and transmitted along the optical path again to the silicone oil 30g. And the like to the beam splitter 8g.

On the other hand, the beam splitter 8g
The ray of light r_FourIs the second plane 6g, silicone oil
30g, passing through the fifth plane 21g, and into the sixth plane 23g
The silicone oil is more reflected and along its optical path again
The light passes through 30 g or the like and travels to the beam splitter 8 g. So
And the ray r_Three, R_FourIs a beam splitter 8g and
Reflected by the third plane 9g, and combined and interfered
And a light ray (parallel light) r _FiveOut of the light exit surface 11g as
Is forced. Further, the ray r_FiveIs the collimating lens 1
2b converged by ray r₆As the optical fiber 14b
Will be incident.

Next, the operation of the present invention will be described with reference to FIG. When the first and second slab type waveguide plates 1A ₃ and 1B ₃ and the third slab type waveguide plate 1C ₃ are relatively moved, the third slab type waveguide plate C ₃ is moved here. The moving mechanism is performed by a known means using a linear guide, a precision feed mechanism, or the like.

Referring to FIG. 6, third slab type waveguide plate 1C
Consider a case where ₃ is moved linearly by a distance d in the interference detection direction. At this time, the first and second slab type waveguide plates 1A ₃ , 1
B ₃ and sandwiched between the narrow gap between the third slab waveguide plate 1C _3, is held by the capillary phenomenon. The distance traveled by the ray r ₃ transmitted through the beam splitter until it is reflected by the seventh plane 23 g increases by d · sin θ, and the ray r ₄ reflected by the beam splitter 8 g is shifted by the sixth plane 22.
The distance traveled before being reflected by g decreases by d · sin θ. Therefore, the change in the distance traveled by light is 2d · si
a decrease of growth and 2d · sin [theta of n.theta, the third refractive index of the slab type waveguide plate C ₃ as n, the maximum moving distance d
_{Assuming MAX} , the maximum optical path length difference in this optical path is 4n ·
d _MAX · sin θ.

This is because the wave number resolution is 2 compared to the prior art.
This is equivalent to a twofold improvement. Moreover, the specific structure of the slab type waveguide, the wavelength of the incident light in the near infrared (such as 1550nm as an example), in the case of using a quartz material, 8 [mu] m core layer g _2, the upper clad layer g ₁ 15μ
m, and 20μm lower cladding layer g _3, the thickness of the combined are configured to be 50μm or less. Therefore, it is possible to significantly reduce the thickness and weight as compared with the prism type, and since the slab type waveguide can be formed by lithography technology, it is possible to mass-produce the interferometer at low cost. it can.

Next, a ninth embodiment of the present invention will be described with reference to FIGS. 14 (a), (b) and (c). The Michelson interferometer 4A has a first slab type waveguide plate 1A ₄
A second slab type waveguide plate 1B ₄ , a third slab type waveguide plate 1C ₄ , a beam splitter 8h for dividing a light beam into reflected light and transmitted light, and a refractive index matching means for matching a refractive index. Silicone oil 30h, optical fiber 2h and connecting part 3h as light incident means, connecting part 13h and optical fiber 14h as light detecting means, convert diffused light into parallel light, and convert parallel light into convergent light. Reflection curved surfaces (parabolic surface for collimation, parabolic surface for condensing) 5h and 12h are provided as conversion means.

As shown in FIGS. 14 (a), (b) and (c), the first and second slab type waveguide plates 1A ₄ and 1B
₄ includes a core layer h _2, the upper clad layer h ₁ and the lower clad layer h ₃ provided on the upper and lower surfaces of the core layer h ₂
It is composed of The first slab waveguide plate 1A ₄ is disposed on the peripheral side surface, and the light incident surface 4h is formed at a position for installing the optical fiber 2h via the connection part 3h, from the light incident surface 4h A reflection curved surface (parabolic surface for collimation) 5h as a conversion means formed on the optical path of the light beam, and a beam splitter 8h arranged on the optical path of the light beam which is reflected from the reflection curved surface 5h and becomes parallel light are adjacent to each other. The first plane 7h formed at the position and the second plane 6 formed on the optical path of the reflected light from the beam splitter 8h
b. The end surface (light irradiation surface) of the optical fiber 2h is set at the focal position of the collimating paraboloid 5h.

On the other hand, the second slab type waveguide plate B ₄ is disposed on the peripheral side surface thereof, and extends along the first plane 7 h.
A third formed at a position facing the beam splitter 8h
A plane, a fourth plane 10h formed on the optical path of the transmitted light from the beam splitter 8h and an extension of the second plane, and light beams transmitted from the beam splitter 8h and the third plane 9h. A reflection curved surface (parabolic surface for condensing) 12h serving as a conversion means, and an optical fiber 14 disposed on the optical path of a light beam reflected from the reflection curved surface 12h, are provided via the connecting component 13h. And a light exit surface 11h formed at a position where the light exits. Note that the end surface (light incident surface) of the optical fiber 14h is
h is located at the focal position.

The third slab type waveguide plate 1C ₄ is formed on the peripheral side surface of the third slab type waveguide plate 1C ₄ .
1B and fifth plane 21h is disposed at the position facing to the second plane 6g and the fourth plane 10h of _4, the reflected from the beam splitter 8h second plane 6h and fifth plane 2
A sixth plane 22h formed at a position where light rays passing through 1h are reflected along the optical path, and a fourth plane 10h and a sixth plane 21h passing through the beam splitter 8h.
And a seventh plane 23h formed at a position to reflect the light beam transmitted through along the optical path. The sixth plane 22h and the seventh plane 23h are formed in mirror-like shapes that reflect light rays.

[0118] FIG. 14 (a), the as shown in (b), (c), the silicone oil (refractive index matching liquid layer) 30h of the refractive index matching means, the first slab waveguide plate 1A ₄ second _Fourth of the two flat surfaces 6h and the second slab type waveguide plate 1B4
The plane 10h, is provided between the third fifth plane 21h of the slab type waveguide plate 1C _4. The refractive index matching means may be any member that forms each of the slab type waveguide plates 1A ₄ , 1B ₄ , 1C ₄ as long as it has a similar refractive index. As an example, each of the slab type waveguide plates 1A ₄ , 1B ₄ , and 1C ₄ are made of quartz, use silicone oil 30h, and are configured to be held by capillary action.

As shown in FIGS. 14 (a), (b) and (c), the beam splitter 8h is connected to the first slab type waveguide plate 1.
A first plane 6h of A _4, are fixed by an adhesive or the like between the third plane 9h of the second slab waveguide plate 1B _4,
The material of each slab type waveguide plate 1A ₄ , 1B ₄ , 1C ₄ ,
It is configured such that the transmittance and the reflectance become a predetermined ratio depending on the angle of the transmitted light beam. As an example of the beam splitter. 8h, so as to deposit and it is interposed a thin film of a metal or a dielectric, or both, also the transmission member (core layer h ₂ the same quality of the slab type waveguide plate) formed are doing. Note that the beam splitter 8h has a first
A thin film such as a metal and / or a dielectric may be formed on the flat surface 7h or the third flat surface 9h by thin film forming means such as vapor deposition.

Next, the optical path of the light beam will be described. Figure
15 (a), (b) and (c), an optical fiber
Light incident from the light incident surface 4h as diffused light by 2h
Line r ₁Is converted into parallel light by the reflection curved surface 5h and the light beam r
_TwoIs incident on the beam splitter 8h. And
Light beam r split and transmitted by the beam splitter 8h _Three
Penetrates the fourth plane 10h and the silicone oil 30h.
After passing through the fifth plane 21h and reflecting on the seventh plane 23h
Silicone oil along the transmitted light path
The light passes through 30h and the like and goes to the beam splitter 8h.

On the other hand, the beam splitter 8h
The ray of light r_FourIs the second plane 6h, silicone oil
30h, passing through the fifth plane 21h, and into the sixth plane 22h
The silicone oil is more reflected and along its optical path again
The light passes through 30h and the like and goes to the beam splitter 8h. So
Then, the light beam sent to the beam splitter 8h side
r _Three, R_FourIs the beam splitter 8h and the third flat
Reflected by the surface, combined and interfere with each other_Five
(Parallel light) is incident on the reflection curved surface 12h. further,
The light ray r by the reflection curved surface 12c_FiveIs converted from collimated light
Converged ray r₆As a light detecting means on the light emitting surface 11h
Output to the stage (connection component 13h, optical fiber 14h)
Will be.

The operation of the present invention is the same as that of the third embodiment shown in FIG. 6, and the wave number resolution is twice as large as that of the prior art. In the fourth embodiment, the optical fibers 2h and 14h are connected to the Michelson interferometer by the connecting component 3.
h and 13h, input / output to / from each of the slab type waveguide plates 1A ₄ and 1B ₄ is performed, and the optical path in the interferometer does not pass through free space at all. . In addition, since the optical path is not interrupted by the optical component, which is a drawback of the prior art 2, an accurate measurement value can be obtained.

Next, a tenth embodiment of the present invention will be described with reference to FIGS. 15A, 15B and 15C.
The Michelson interferometer 5A includes a first slab type waveguide plate 1A.
_5, a second slab waveguide plate 1B _5, a third slab waveguide plate 1C _5, a beam splitter 8j to split the light into reflected light and transmitted light, the refractive index matching means for matching the refractive index The silicone oil 30j, the optical fiber 2j and the connecting part 3j as the light incident means, the connecting part 13j and the optical fiber 14j as the light detecting means, convert the diffused light into parallel light, and convert the parallel light into convergent light. And transmission curved surfaces 5j and 12j as converting means.

As shown in FIGS. 15A, 15B and 15C, the first and second slab type waveguide plates 1A ₅ and 1B
₅ includes a core layer j _2, the upper clad layer j ₁ and the lower clad layer j ₃ provided on the upper and lower surfaces of the core layer j ₂
It is composed of The first slab waveguide plate 1A ₅ is disposed on the peripheral side surface, and the light incident surface 4j is formed at a position for installing the optical fiber 2j through the connecting part 3j, on the light incident surface 4j A transmission curved surface 5j to be formed, a first plane 7j which is disposed on an optical path of a light beam which passes through the transmission curved surface 5h and becomes parallel light, and is formed at a position adjacent to the beam splitter 8j, and a beam from the beam splitter 8h. A second plane 6j formed on the optical path of the reflected light. In addition, the end surface (light irradiation surface) of the optical fiber 2h is provided at the focal position of the transmission curved surface 5h.

[0125] On the other hand, the second slab waveguide plate B ₅ is arranged on the peripheral side surface, along the first plane 7j, and,
A third formed at a position facing the beam splitter 8j
A plane 9j, a fourth plane 10j formed on the optical path of the transmitted light from the beam splitter 8j and an extension of the second plane 6j, and light rays transmitted from the beam splitter 8j and the third plane 9j. And a light exit surface 11j formed at a position where the optical fiber 14j is installed via the connection component 13j.
j and a transmission curved surface 12j as a conversion means. The end face of the optical fiber 14j (light incident face)
Is set at the focal position of the transmission curved surface 12j.

The third slab type waveguide plate 1C ₅ is formed on the peripheral side surface, and the both slab type waveguide plates 1A ₅ ,
A fifth plane 21j that is disposed at the position facing to the second plane 6j and fourth plane 10j of 1B _5, wherein the beam splitter is reflected from 8j second plane 6h and fifth plane 2
A sixth plane 22j formed at a position for reflecting a light beam transmitted through the beam splitter 1j along the optical path, a fourth plane 10j and a sixth plane 21j transmitted through the beam splitter 8j.
And a seventh plane 23j formed at a position to reflect a light beam transmitted through along the optical path. The sixth plane 22j and the seventh plane 23j are formed in mirror-like shapes that reflect light rays.

[0127] FIG. 15 (a), the as shown in (b), silicone oil as index matching means (refractive index matching liquid layer) 30j, the second plane 6j of the first slab waveguide plate 1A ₅ and the second fourth plane 10 of the slab type waveguide plate 1B ₅
and j, are provided between the fifth plane 21j of the third slab waveguide plate 1C _5. The refractive index matching means may be any member that forms each of the slab type waveguide plates 1A ₅ , 1B ₅ , and 1C ₅ as long as they have similar refractive indexes. As an example, each slab type waveguide plate 1A ₅ , 1B ₅ , and 1C ₅ are made of quartz, use silicone oil 30j, and are configured to be held by capillary action.

[0128] As shown in Figure 15 (a), (b) , the beam splitter 8j has a first plane 6j of the first slab waveguide plate 1A _5, third second slab waveguide plate 1B ₅ The slab type waveguide plates 1A ₅ , 1B ₅ , 1C ₅ are fixed to the flat surface 9j with an adhesive or the like, and the transmittance and the reflectance are set to predetermined ratios depending on the material of each slab type waveguide plate 1A ₅ , 1B ₅ , 1C ₅ and the angle of the transmitted light beam. It is configured to be. As an example of the beam splitter 8j, either interposing a thin film such as a metal or a dielectric, or both, or formed as deposited on transparent member (core layer j ₂ the same quality of the slab type waveguide plate) ing. Note that the beam splitter 8j may be formed by forming a thin film such as a metal and / or a dielectric on the first plane 7j or the third plane 9j by thin film forming means such as vapor deposition.

Next, the optical path of the light beam will be described. Figure
15 (a), (b) and (c), an optical fiber
Light incident from the light incident surface 4j as diffused light by 2j
Line r ₁Is converted into parallel light by the transmission curved surface 5j and the light beam r
_TwoIs incident on the beam splitter 8j. And
Light beam r transmitted by the beam splitter 8j_ThreeAnd the reflection
Light ray r_FourIs divided. Pass through the beam splitter 8j
The ray of light r_ThreeIs the fourth plane 10j and the silicone
After passing through the file 30j and entering the fifth plane 21j, the seventh flat
Again along the optical path reflected and transmitted by the surface 23j.
The beam splitter 8 transmits through the cone oil 30j and the like.
Go to j.

On the other hand, the beam splitter 8j
The ray of light r_FiveIs the second plane 6j, silicone oil
30j, passing through the fifth plane 21j to form the sixth plane 22j
The silicone oil is more reflected and along its optical path again
The light passes through 30j and the like and goes to the beam splitter 8j. So
Then, the light beam sent to the beam splitter 8j side
r _Three, R_FourIs the beam splitter 8j and the third flat
Reflected by the surface, combined and interfere with each other_Five
(Parallel light) as the transmission curved surface 12j of the light exit surface 11j
Output from The light ray r is transmitted by the transmission curved surface 12j._Five
Is converted from parallel light to convergent light and the ray r₆As light fa
This is output to the receiver 14j.

The operation corresponding to this embodiment is the same as that of the third embodiment shown in FIG.
It has improved twice. In the sixth embodiment, the optical fibers 2j and 14j are connected to the Michelson interferometer by connecting parts 3j and 13j to the respective slab-type waveguide plates 1A ₅ and 1A.
B and ₅ to perform the human output, not affected by the external environmental change (humidity change and the like) for the optical path does not pass through the free space in exactly the interferometer in. Also, the disadvantage of the prior art 2 was that
Since the optical path is not interrupted by the optical component, an accurate measurement value can be obtained. And because the optical axis does not move,
The connecting parts 3j, 13j may be arranged at separated positions without being attached to the transmission curved surfaces 5j, 12j.

Next, with respect to the third to fifth and eighth to tenth embodiments, Michelson interferometers A ₃ , 1A ₃ ... (Those having a third prism column and a third slab type waveguide plate) The method of measuring the moving distance of the prism (slab-type waveguide plate) in ()) will be described with reference to FIG. In addition, 32 is a monochromatic coherent light source having a known wavelength, 33 is a multiplexing element used to make light from the light source 32 incident on the interferometer of the present invention, and 34 is light capable of detecting light emitted from the light source 32. A detector 35 is a light source to be measured whose spectrum is unknown, 36 is a photodetector having sensitivity to the light source to be measured, and 37 is a detector 34 which extracts light from the light source 32 from light emitted from the interferometer. Reference numeral 38 denotes one of the Michelson interferometers of the present invention.

Assuming that the oscillation wavelength of the monochromatic coherent light source 32 is λ, the moving distance of the prism is d, and the refractive index is n, the difference in the optical path length inside the interferometer with respect to the moving distance of the prism is 4n · d · sin θ. In terms of wavelength λ, it is expressed as 4n · d · sin θ / λ. Therefore, the fluctuation of the signal intensity obtained on the detector 34 due to the interference of light from both optical paths is expressed by the following equation.

[0134]

[Formula 1]

From this equation, the fluctuation period of the interference signal intensity with respect to the movement d of the prism is λ / (8n · sin θ). For example, if the interference intensity changes by N periods, the optical path length difference changes by Nλ / 2, and Is Nλ / (8
n · sin θ). By measuring the interference signal as described above, the movement distance of the prism and the change in the optical path length can be measured. Here are some specific numbers:
The wavelength λ is a 632.8 nm wavelength of a helium neon laser. For example, when the refractive index n is 1.5 and the interference signal intensity changes by one period, the change in the optical path length difference is 316.4n.
m, which corresponds to a moving distance of the prism of 74.6 nm. Naturally, even when the fluctuation of the interference signal intensity is less than one cycle, the optical path length change amount and the prism moving distance can be measured from the signal intensity change. This measuring method can also be used independently as a moving amount measuring means if only the monochromatic coherent light source 27, the photodetector 29 and the interferometer 32 are used.

In the first and second embodiments and the sixth and seventh embodiments, the difference in the optical path length inside the interferometer with respect to the moving distance of the prism is 2n.
It is expressed by d · sin θ, and 2n ·
It is expressed by d · sin θ / λ. Therefore, the variation of the signal strength can be calculated such that 4nd in parentheses on the left side of Equation 1 is 2nd, and 8n in parentheses on the right side is 4n. As a result, the fluctuation cycle of the interference signal intensity with respect to the movement d of the prism is λ / (4n · sin θ). For example, if the interference intensity changes by N periods, the optical path length difference becomes Nλ.
/ 2, and the moving distance of the prism is Nλ / (4n · si
nθ). By measuring the interference signal as described above, the movement distance of the prism and the change in the optical path length can be measured. Here, when giving specific numerical values, the wavelength λ is 632.8 nm of a helium neon laser,
For example, when the refractive index n is 1.5 and the interference signal intensity changes by one period, the change in the optical path length difference corresponds to 316.4 nm, and the movement distance of the prism corresponds to 149.2 nm. This measuring method can also be used independently as a moving amount measuring means if only the monochromatic coherent light source 27, the photodetector 29 and the interferometer 32 are used.

As the material of the prism column or the slab type waveguide plate, quartz is used in all the embodiments, but any material may be used as long as the material transmits light.
That is, general glass materials, semiconductors such as silicon, germanium, and zinc selenide, ionic crystals such as calcium fluoride, potassium bromide, and lithium niobate; polymers such as polyimide and polymethyl methacrylate (PMMA); Even if plastic or the like is used, the same effect can be obtained. In particular, in the case of molding using plastic as a material and using a mold, productivity of both prism columns or both slab type waveguide plates is facilitated and mass production is possible. In addition, the cost can be reduced. In this embodiment, silicone oil is used for the refractive index matching means, but any liquid may be used as long as it has a refractive index close to that of the prism material.

Further, in all the embodiments, near-infrared rays are used as incident light, but any wavelength may be used as long as the light transmits through a material to be used. Further, although the input and output of light are performed by optical fibers, a light source such as a super luminescence diode, a white light source or a light emitting diode may be used for the optical fiber on the incident side. The same operation can be performed by replacing the optical fiber on the output side with a photodetector such as a photodiode or a pyroelectric detector.

Further, in all the embodiments, when each prism column and each slab-type waveguide plate are moved in parallel, the area of the photodetector is made larger for converging light beams. In addition, a light detection means whose light detection efficiency does not depend on the angle of incident light is used. Also, when the end face of the optical fiber is the light detecting means, the Nu
The detection means uses a material aperture (numerical aperture) that is considerably larger than the change in the light incident angle, and the light detection efficiency does not depend on the angle of the incident light.

In the first and second and sixth and seventh embodiments, the first prism column or the first slab type waveguide plate on the light incident side is fixed, and the second prism column is fixed. And the second slab type waveguide plate are moved, but this is merely an example, and the relative positions of both prism columns and both slab type waveguide plates may be changed. A two-slab type waveguide plate is fixed and the first prism column and the first slab type waveguide plate are moved, and both prism columns and both slab type waveguide plates are moved in the same manner. I do. And
In the third to fifth and eighth to tenth embodiments, the third prism column or the third slab type waveguide plate is moved, but the first and second prism columns or the first and second prism columns are moved. The same operation is performed even if the two-slab type waveguide is moved or both are moved and relatively moved.

In the first and second embodiments, and in the sixth and seventh embodiments, the one angle included in the predetermined angle θ between the first plane and the second plane is 45 degrees. The set angle of one interior angle is 3 as shown in FIG.
The angle may be set to an arbitrary predetermined angle θ such as 0 degree or 60 degrees as shown in FIG. 18B. The predetermined angle θ is in a range of 0 degree <θ <90 degrees. It can be. Note that the predetermined angle θ of one interior angle is 0 degree and 90 degrees.
If the degree is higher than the above, it is difficult to secure an optical path for transmitting or reflecting a light beam having a certain width, and the interferometer does not function. In the first to fourth embodiments, the reflection curved surface (including the first curved surface, the second curved surface, and the curved surface) is formed as a mirror surface. However, the mirror surface is formed by satisfying the condition of total reflection. It is possible to reflect the transmitted light without it.

In the third to fifth embodiments and the eighth to tenth embodiments, the example in which the incident angle θ of the light beam with respect to the beam splitter surface is 45 degrees is shown in FIG. As described above, it is possible to set an arbitrary angle such as 30 degrees or 60 degrees. Along with this, the shapes of the prism columns A ₃ , B ₃ , C ₃ (slab type waveguide plates 1A ₃ , 1B ₃ , 1C ₃ ...) Also change.

Further, in the third to fifth embodiments and the eighth to tenth embodiments, the incident angle θ ₁ and the exit angle θ ₂ of the light beam are other than 45 degrees, 30 degrees and 60 degrees. More specifically, as shown in FIG. 19, within a range satisfying certain conditions, θ ₁ , θ ₂ , φ ₁ , φ ₂ ,
φ ₁₂ and φ ₂₃ can take any values in a range larger than 0 degree and smaller than 90 degrees (0 degree <(θ ₁ ...) <90 degrees).

(1) Refractive indices n ₁ , n ₂ , n ₁ ',
n ₂ ′, n ₃ , n ₃ ′ ≧ 1 (2) According to Snell's law, n ₁ · sin θ ₁ =
_{n 2 · sinθ 2 n 1 '} · sinφ 1 = n 3 · sinφ 13 n 2' · sinφ 2 = n 3 '· sinφ 23 (3) θ 1, θ 2, φ 1, the relation φ ₂ θ ₁ + θ ₂ + φ ₁ + φ ₂ = π (4) The moving direction and the boundary surfaces 1 and 2 are parallel to each other. (5) The mirror surfaces 1 and 2 are each perpendicular to the optical axis. (6) The beam splitter surface and the boundary surface (moving direction) are not parallel. Incidentally, in the third to fifth embodiments and the eighth to tenth embodiments, n ₁ = n ₂ = n ₁ ′ = n
₂ ′ = n ₃ = n ₃ ′, and θ ₁ = θ ₂ , φ ₁ =
φ ₂ , φ ₁₃ = φ ₂₃ = (π / 2) −θ ₁ , and the beam splitter surface and the boundary surface (moving direction) are perpendicular.

In the third to fifth embodiments and the eighth to tenth embodiments, FIGS.
As shown in (b), (c), (d), (e), and (f), the combination of each prism column (each slab type waveguide plate) of the Michelson interferometer 1b (1c...) You may go freely. In a configuration in which the conversion means is not provided in the optical path, a configuration is adopted in which the light incidence means or the light detection means is provided with a conversion lens. In particular, in these Michelson interferometers 1b (1c...), Since the optical axis is constant even when the relative movement is performed, the light ray incident path and the light ray detection path are defined by prism prisms and slab type guides. It may be set at a position separated from the wave plate.

Further, in all the embodiments, the converting means or the light beam incident means and the light detecting means provided in the optical path may be constituted as shown in FIG. In addition, since the direction of the light beam is opposite and the configuration of the light detection means does not change,
Here, only the light detecting means will be described. As shown in FIG. 21A, the end face of the optical fiber 2p is set on the light irradiation surface 4p via the connecting part 3p. Then, the material of the prism column (core layer of the slab type waveguide plate) is changed by a predetermined means as a conversion means into an optical path from the light irradiation surface 4p to the first plane (see FIGS. 3 and 5). Alternatively, the refractive index may be changed. For example, by diffusing silver (Ag) atoms into the prism (core layer), the refractive index distribution of a light beam can be converted into parallel light (parallel light is converged light).

Further, as shown in FIG. 21 (b), a GRIN lens may be provided on the light irradiation surface 4q via the connecting part 3q to convert the light from the optical fiber 2q. Further, as shown in FIG. 21 (c), a Fresnel zone plate (FZP) is attached to the light irradiation surface 4r via the connection component 3r, and the diffused light from the optical fiber is converted into parallel light (parallel light is converged light). It is good also as a structure which performs.

Further, in the first, second, sixth, and seventh embodiments, a transmission curved surface (see FIGS. 5 and 15) may be formed at the position of the light incident surface. In the first, second, sixth, and seventh embodiments, the planes may have other intervening surfaces as long as the planes are adjacent to each other as long as the optical path length changes. good. Further, in the first to fifth embodiments, the reflection curved surface or the transmission curved surface is described as a parabolic surface, but is configured as a spherical surface or a toroidal surface (a curved surface having a different curvature in a horizontal direction and a vertical direction). You may. In the sixth to tenth embodiments, the reflection curved surface or the transmission curved surface may be a cylindrical surface.

[0149]

As described above, according to the present invention, a Michelson interferometer for use in Fourier transform spectroscopy or the like uses the first and third planes of two prism columns or two slab-type waveguide plates. Since they are movably arranged adjacent to each other, no light is lost or fluctuated in the optical path where the incident light reaches the light detecting means. Therefore, an accurate interferogram can be measured, and an accurate Michelson interferometer can be configured. Further, since the position of the output light beam is always constant by converging and reflecting the light beam on the light detecting means by the reflection curved surface, it is possible to configure an integrated Michelson interferometer.

Further, since the main part of the Michelson interferometer is composed of two prism columns or two slab-type waveguide plates, it is possible to make the structure lightweight and small, and to perform fine processing. Since it is not necessary, it is possible to provide a robust structure having excellent environmental resistance. Further, since light is input / output through an optical fiber and the optical path hardly passes through free space, the optical path is not affected by external environmental changes (such as humidity). Further, by using the waveguide structure, it is possible to reduce the thickness and mass production, and to realize a small and inexpensive Michelson interferometer.

Further, by providing a collimating lens, a GRIN lens, or a Fresnel zone plate as a conversion lens in the light beam incidence means, the setting of the light incidence means is facilitated, and the optical axis adjustment of the interferometer is facilitated. Become.

In the Michelson interferometer, two prism columns or two slab-type waveguide plates having a beam splitter formed therebetween and a third prism column or a third slab-type waveguide having two boundaries formed. Bring each wave plate into contact,
In an interferometer used at a boundary through a refractive index matching means, an accurate Fourier transform spectrometer with high resolution and no loss and no loss fluctuation has been made possible.

Further, the Michelson interferometer using the third prism column and the third slab type waveguide plate does not change the optical axis, so that the moving distance is not limited and a high-resolution spectrum can be obtained. . Further, since a difference in optical path length can be formed at the positions of the sixth plane and the seventh plane, high-performance detection measurement can be performed.

Of course, by using the waveguide structure, even a Michelson interferometer using the third slab type waveguide plate can be made thin and mass-produced, and a small and inexpensive Michelson interferometer can be realized. be able to.

Further, since a monochromatic coherent light source and a photodetector corresponding to the wavelength are used, and a Michelson interferometer is used, the most important differences in the optical path length and the prism movement amount when measuring the interferogram are determined. Can be measured.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a Michelson interferometer according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating an operation of the Michelson interferometer according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a Michelson interferometer according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating an operation of the Michelson interferometer according to the second embodiment of the present invention.

FIGS. 5A and 5B are a plan view and a perspective view showing a configuration of a Michelson interferometer according to a third embodiment of the present invention.

FIG. 6 is a plan view illustrating an operation of the Michelson interferometer according to the third embodiment of the present invention.

FIGS. 7A and 7B are a plan view and a perspective view showing a Michelson interferometer according to a third embodiment of the present invention.

FIGS. 8A and 8B are a plan view showing a configuration of a Michelson interferometer according to a fourth embodiment of the present invention and a perspective view of the Michelson interferometer.

FIGS. 9A and 9B are a plan view showing a configuration of a Michelson interferometer according to a fifth embodiment of the present invention and a perspective view of the Michelson interferometer.

FIGS. 10A and 10B are a perspective view and a magnified view of a slab type waveguide plate showing a Michelson interferometer according to a sixth embodiment of the present invention.

FIGS. 11A and 11B are a perspective view showing a Michelson interferometer according to a seventh embodiment of the present invention and an enlarged view of a slab-type waveguide plate.

FIGS. 12A and 12B are a perspective view and a magnified view of a slab waveguide plate showing a Michelson interferometer according to an eighth embodiment of the present invention.

FIG. 13 is a perspective view showing a Michelson interferometer according to an eighth embodiment of the present invention.

FIGS. 14A, 14B, and 14C are plan views showing a configuration of a Michelson interferometer according to a ninth embodiment of the present invention;
It is a perspective view of a Michelson interferometer, and an enlarged view of a slab type waveguide plate.

FIGS. 15 (a), (b) and (c) show a tenth embodiment of the present invention.
FIG. 2 is a plan view showing the configuration of the Michelson interferometer of the embodiment, a perspective view of the Michelson interferometer, and an enlarged view of a slab type waveguide plate.

FIG. 16 is a schematic diagram showing a method of measuring a moving distance using the Michelson interferometer of the present invention.

FIG. 17 is a schematic diagram showing an application example of the Michelson interferometer according to the first, second, sixth, and seventh embodiments of the present invention.

18 (a) and (b) are third to fifth embodiments of the present invention.
FIG. 15 is a schematic diagram showing an application example of the Michelson interferometers of the eighth and tenth embodiments.

FIG. 19 shows third to fifth and eighth to tenth embodiments of the present invention.
FIG. 3 is a schematic diagram illustrating a configuration principle of the Michelson interferometer according to the embodiment.

FIGS. 20 (a), (b), (c), (d), (e),
(F) shows the third to fifth and eighth to tenth aspects of the present invention.
FIG. 9 is a schematic diagram showing another configuration of the Michelson interferometer according to the embodiment.

FIGS. 21 (a), (b), and (c) are schematic views showing other configurations of the light beam incidence means or the light detection means of all Michelson interferometers.

FIG. 22 is a schematic diagram of a conventional Michelson interferometer for Fourier transform spectroscopy.

FIG. 23 is a schematic view of a conventional Michelson interferometer for Fourier grinding spectroscopy.

[Explanation of symbols]

1,1a, 1b, 1c, 1d, 1e Michelson interferometer 1A, 2A, 3A, 4A, 5A Michelson interferometer _{A 1, A 2, A 3} , A 4, A 5 first prism pillar 1A _1, 1A ₂ , 1A ₃ , 1A ₄ , 1A ₅ First slab type waveguide plate B ₁ , B ₂ , B ₃ , B ₄ , B ₅ Second prism column 1 B ₁ , 1 B ₂ , 1 B ₃ , 1 B ₄ , 1 B ₅ Second slab type waveguide plate C ₃ , C ₄ , C ₅ Third prism column 1C ₃ , 1C ₄ , 1C ₅ Third slab type waveguide plate 2, 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2
h, 2j Optical fiber (light beam incident means) 3, 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3
h, 3j Connection parts (light beam incidence means) 4, 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4
h, 4j Light incident surface 5, 5a, 5b, 5c, 5d Conversion means (reflection curved surface,
Transmission curved surface, refractive index conversion means, first curved surface, curved surface, collimating lens (conversion lens) 5e, 5f, 5g, 5h, 5j conversion means (reflection curved surface,
Transmission curved surface, refractive index conversion means, first curved surface, curved surface, collimating lens (conversion lens)) 6, 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6
h, 6j Second plane (second reflection plane) 7, 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7
h, 7j First plane 8, 8a, 8b, 8c, 8d, 8e, 8f, 8g, 8
h, 8j Beam spiriter 9, 9a, 9b, 9c, 9d, 9e, 9f, 9g, 9
h, 9j Third plane 10, 10a, 10b, 10c, 10d, 10e, 10
f, 10g, 10h, 10j Fourth plane (fourth reflection plane) 11, 11a, 11b, 11c, 11d, 11e, 11
f, 11g, 11h, 11j Light-emitting surface 12, 12a, 12b, 12c, 12d Conversion means (reflection curved surface, transmission curved surface, refractive index conversion means, second curved surface, curved surface, parabolic surface for condensing, lens for collimation (Conversion lens) 12e, 12f, 12g, 12h, 12j Conversion means (reflection curved surface, transmission curved surface, refractive index conversion means, second curved surface,
Curved surface, parabolic surface for condensing, lens for collimation (conversion lens)) 13, 13a, 13b, 13c, 13d, 13e, 13
f, 13g, 13h, 13j Connection parts (light detection means) 14, 14a, 14b, 14c, 14d, 14e, 14
f, 14g, 14h, 14j Optical fibers (light detecting means) 21b, 21c, 21d, 21g, 21h, 21j
Fifth plane 22b, 22c, 22d, 22g, 22h, 22j
Sixth plane 23b, 23c, 23d, 23g, 23h, 23j
Seventh plane 30b, 30c, 30d, 30g, 30h, 30j
Curvature matching means 32 Monochromatic coherent light source having a known wavelength 33 Combining element used to make light from the monochromatic coherent light source incident on the interferometer of the present invention 34 Light detection capable of detecting light emitted from the monochromatic coherent light source Instrument 35 Light source to be measured whose spectrum is unknown 36 Photodetector having sensitivity to the light source to be measured 37 Demultiplexer element that extracts light of a monochromatic coherent light source from the light emitted from the interferometer and separates it into detector 34 38 Interferometer of the present invention

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F064 AA03 CC01 CC04 EE01 GG02 GG06 GG13 GG22 GG44 GG51 JJ15 2F065 AA03 DD03 DD04 FF52 JJ01 JJ15 LL02 LL04 LL46 LL47 LL67 QQ16 2G020 AA04 CB05 CB05

Claims (14)

[Claims] 1. A beam splitter for splitting a light beam into a reflected light beam and a transmitted light beam, a first prism column, a second prism column, a light beam incident unit, a light detection unit, and the light beam is a diffused beam. Conversion means for converting the diffused light into parallel light, and converting the parallel light into convergent light when the light ray is parallel light, wherein the first prism column is provided with the light incident means. A light incident surface disposed at a position, a first plane adjacent to the beam splitter and disposed on an optical path of light incident from the light incident surface, and reflecting light from the beam splitter in the direction of the optical path. A second plane disposed so as to face the beam splitter, wherein the second prism column is disposed at a position facing the beam splitter along the first plane; The light beam towards its path A fourth plane disposed so as to reflect the light, and a light exit surface disposed at a position where the light detection means is installed; in a light path from the light incident surface to the first plane; The conversion means is provided on one of the means, and the third
A reflection curved surface is provided in an optical path from a plane to the light exit surface, wherein the first prism column and the second prism column are
A Michelson interferometer, which is relatively movable along the first plane and the third plane in the direction of changing the optical path length of light rays. 2. A beam splitter for splitting a light beam into reflected light and transmitted light, a first slab type waveguide plate, a second slab type waveguide plate, a light beam incident means, a light detection means, and the light beam. When the light is a diffused light, the diffused light is converted into parallel light, and when the light beam is a parallel light, the conversion means is configured to convert the parallel light into convergent light.The first slab-type waveguide plate includes: A light incident surface disposed at a position where the light incident means is installed, a first plane adjacent to the beam splitter and disposed on an optical path of light incident from the light incident surface, and a light from the beam splitter. A second plane disposed so as to reflect in the direction of the optical path, wherein the second slab type waveguide plate is disposed at a position facing the beam splitter along the first plane. Plane and light from the beam splitter A fourth plane disposed so as to reflect the light in the direction of the optical path, and a light-emitting surface disposed at a position where the light detection unit is installed. In the optical path from the light-incident surface to the first plane, And the third
The conversion means is provided in at least one of the optical paths from the plane to the light emitting surface, and the first slab-type waveguide plate and the second slab-type waveguide plate are the first plane and the second slab-type waveguide, respectively. A Michelson interferometer, which is relatively movable along a third plane in a direction of changing the optical path length of light rays. 3. The method according to claim 1, wherein the converting means is provided in the optical path.
The Michelson interferometer according to claim 2, wherein the Michelson interferometer is provided in at least one of the light beam incident unit and the light detection unit. 4. A first prism column, a second prism column, a third prism column, a beam splitter for splitting a light beam into reflected light and transmitted light, and refractive index matching means for matching a refractive index. , A light incident means, and a light detecting means, wherein the first prism column is adjacent to the light incident surface disposed at a position where the light incident means is installed, and the beam splitter, and from the light incident surface A first plane disposed on an optical path of an incident light beam; and a second plane disposed on an optical path of a light beam reflected from the beam splitter, wherein the second prism column includes the first plane. A third plane disposed at a position facing the beam splitter along the axis, a fourth plane disposed on an optical path of a light beam passing through the beam splitter and an extension of the second plane, Placed at the position where the The third prism column is disposed at a position facing the second plane of the first prism column and the fourth plane of the second prism column. A plane, a sixth plane arranged to reflect light rays sent from the first plane through the second plane and the fifth plane in the direction of the optical path, and a third plane from the third plane. A fourth plane and a seventh plane disposed so as to reflect the light beam transmitted through the fifth plane in the direction of the optical path, wherein the refractive index matching unit is configured to include the second plane and the fifth plane. A first prism column and a second prism column interposed between four planes and the fifth plane;
The third prism column includes the second plane and the fourth prism.
A Michelson interferometer, which is relatively movable along a plane and in the direction of changing the optical path length of light rays along the fifth plane. 5. The method according to claim 1, wherein the light beam is diffused light in the light path from the light incident surface to the first plane and in at least one light path in the light path from the third plane to the light exit surface. 5. The Michelson interferometer according to claim 4, further comprising a conversion unit that converts the diffused light into parallel light and converts the parallel light into convergent light when the light beam is parallel light. 6. A method according to claim 1, wherein said converting means is provided in said optical path.
The Michelson interferometer according to claim 5, wherein the Michelson interferometer is provided in at least one of the light beam incident unit and the light detection unit. 7. A first slab type waveguide plate, a second slab type waveguide plate, a third slab type waveguide plate, a beam splitter for dividing a light beam into reflected light and transmitted light, and a refractive index matching. The first slab type waveguide plate is provided with a light incident surface disposed at a position where the light incident means is installed, and a beam splitter. A second plane disposed adjacently on a light path of a light beam incident from the light incident surface, and a second plane disposed on a light path of a light beam reflected from the beam splitter; A third waveguide disposed at a position facing the beam splitter along the first plane; and a third waveguide disposed on an optical path of a light beam passing through the beam splitter and an extension of the second plane. The fourth plane to be detected and the light detection A light-emitting surface disposed at a position where a step is to be installed, wherein the third slab-type waveguide plate is provided on the second plane of the first slab-type waveguide plate and the second slab-type waveguide plate. A fifth plane arranged at a position facing the fourth plane, and arranged so as to reflect a light beam transmitted from the first plane via the second plane and the fifth plane in a direction of an optical path thereof. A sixth plane, and a seventh plane disposed so as to reflect light rays transmitted from the third plane via the fourth plane and the fifth plane in the direction of the optical path. The rate matching means is interposed between the second plane, the fourth plane, and the fifth plane, the first slab type waveguide plate, the second slab type waveguide plate, and the third slab type waveguide plate. The waveguide plate extends along the second plane, the fourth plane, and the fifth plane. Te, Michelson interferometer, characterized in that the freely move relative to the optical path length changing direction of the light beam. 8. When a light beam is a diffused light, the light beam is transmitted in at least one of an optical path from the light incident surface to the first plane and an optical path from the third plane to the light exit surface. 8. The Michelson interferometer according to claim 7, further comprising a conversion unit that converts the diffused light into parallel light and, when the light beam is parallel light, converts the parallel light into convergent light. 9. The image forming apparatus according to claim 1, wherein said converting means is provided in said optical path.
9. The Michelson interferometer according to claim 8, wherein the Michelson interferometer is provided in at least one of the light beam incident unit and the light detection unit. 10. The apparatus according to claim 1, wherein the conversion means provided in one of the light beam incidence means and the light detection means is a conversion lens. Michelson interferometer. 11. The conversion means provided in the optical path,
10. The Michelson interferometer according to claim 1, wherein the Michelson interferometer is a reflection curved surface. 12. The Michelson interferometer according to claim 11, wherein the reflection curved surface is one of a paraboloid, a toroidal surface, a spherical surface, and a cylindrical surface. 13. The conversion means provided in the optical path,
The Michelson interferometer according to claim 1, wherein the Michelson interferometer is a transmission curved surface. 14. The Michelson interferometer according to claim 13, wherein the transmission curved surface is one of a paraboloid, a toroidal surface, a spherical surface, and a cylindrical surface.