JP2001099874A - Optical sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical sensor in which a reduction in the number of steps of ferrule processing and a reduction in the number of steps of optical fiber binding operations are realized by decreasing the number of expensive ferrule, and which can simply be mass-produced at lower cost. SOLUTION: This optical sensor is constituted by a first or second optical fiber for receiving or emitting lights into or from an optical system; an optical signal process circuit; a third or fourth optical fiber for relaying lights between the optical signal process circuit and the first or second optical fiber; a first or second 2-core holding part for tying up both side ends of the first or second optical fiber or tying up both side ends of the third or fourth optical fiber, to position relatively optical axes of these optical fibers; and a binding part which binds the first or second 2-core holding part and can simultaneously align the optical axis of each of the corresponding optical fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical sensor used for detecting a voltage or a current of a transmission line or a distribution line.

[0002]

2. Description of the Related Art As shown in FIG. 7, a conventional optical sensor, for example, an optical voltage sensor, has a polarizer 1, a quarter-wave plate 2, an electro-optic crystal 3, an analyzer on an optical axis from a light incident side. 4, a first optical fiber 8, a GRI
N lens (0.25 pitch) 5, holder 6, the first
A light-emitting portion composed of a first single-core ferrule 7 on the sensor-side end of the first optical fiber and a first 'single-core ferrule 75 on the opposite end, a second optical fiber 8', and a GRIN lens (0.25 pitch) 5) 5 ', holder 6', second single-core ferrule 7 at the sensor-side end of the second optical fiber
A light receiving portion composed of a second single-core ferrule 75 'at the opposite end to the', an E / O circuit (not shown), an O / E circuit (not shown), and an output result of the O / E circuit A signal processing unit (not shown) composed of a signal processing circuit (not shown) for calculating the E / O circuit, a third optical fiber 12 for transmitting the light of the E / O circuit to the light emitting unit, and a signal to the O / E circuit. A fourth optical fiber 12 'for transmitting the light of the light receiving section, an optical fiber cable 11 in which the third optical fiber 12 and the fourth optical fiber 12' are bundled, and a third single core at the light emitting side end of the third optical fiber A ferrule 76, an optical transmission unit composed of a fourth single-core ferrule 76 'at the light-receiving-side end of the fourth optical fiber, and 73, and a connection between the first single-core ferrule and the third single-core ferrule. A first split sleeve 74,
The second single-core ferrule and the fourth single-core ferrule are connected to each other by a second split sleeve 74 ′.

An electrode terminal 24, a lead wire 34, and an electrode 35 of the electro-optic crystal are electrically connected to the electro-optic crystal 3 of the sensor section for applying a voltage, and a voltage to be measured (not shown) is applied to the electro-optic crystal 3. The voltage is applied to the electrode terminal 24. The polarizer 1
And the front analyzer 4 have a right angle beam splitter (PBS)
You are using

However, as the electro-optic crystal 3, Bi ₁₂
SiO ₂₀ (BSO), KDP or Li with natural birefringence
NbO ₃ , LiTaO ₃ or the like is used. The single-core ferrule is a component for positioning the optical axis of the optical fiber with mechanical precision. The single-core ferrule has a cylindrical outer shape and a hole at the center that substantially matches the outer shape of the optical fiber. The single-core ferrules are fixed on the same straight line, and the optical fibers to be paired are optically aligned. The ferrule processing for integrating the optical fiber and the ferrule is performed by inserting the optical fiber into the hole of the ferrule and fixing the resin, polishing the end surface of the optical fiber together with the ferrule to a mirror surface, and aligning the optical fibers subjected to the ferrule with each other. Is minimized.

[0005]

In the conventional method, each of the first optical fiber of the light emitting section, the third optical fiber of the light transmitting section, the second optical fiber of the light emitting section, and the fourth optical fiber of the light transmitting section has four individual optical fibers. The ferrule is processed for each of the ferrules, and the first optical fiber of the light emitting unit and the third optical fiber of the light transmitting unit are processed.
It is also necessary to separately couple the optical fiber and the second optical fiber of the light emitting unit and the fourth optical fiber of the optical transmission unit, and the use of a large number of expensive ferrules and split sleeves increases the cost. there were.
In addition, it is necessary to perform ferrule processing with many man-hours many times, and it is necessary to perform optical fiber bonding many times, so that there is a problem that a large number of parts and assembly man-hours are required.

The present invention has been made in view of the above-mentioned conventional problems, and in consideration of the problems of the conventional optical voltage sensor, by reducing the number of expensive ferrules, it is possible to reduce the number of man-hours for ferrule processing and reduce the number of optical fiber coupling operations. Reduced man-hours,
It is an object of the present invention to provide a configuration that can mass-produce an optical sensor simply and at low cost.

[0007]

SUMMARY OF THE INVENTION To achieve this object, the present invention basically provides an optical sensor comprising: a first or second optical fiber for inputting or outputting light to an optical system; and an optical signal processing circuit. And a third or fourth optical fiber for relaying light between the optical signal processing circuit and the first or second optical fiber, and bundling both ends of the first and second optical fibers, or A first or second two-core holding portion for bundling both side ends of the third and fourth optical fibers and positioning the optical axes of these optical fibers relative to each other, and connecting the first and second two-core holding portions; The gist of the invention is that the optical fiber is constituted by a coupling portion that can simultaneously align the optical axes of the corresponding optical fibers.

More specifically, the present invention is directed to a sensor section and a first section for inputting light to the sensor section.
An optical fiber, a second optical fiber that forms a pair with the first optical fiber and receives light emitted from the sensor unit, an optical signal processing circuit including an E / O unit, an O / E unit, and a signal processing unit A third optical fiber that sends the light of the E / O section to the first optical fiber, a fourth optical fiber that relays the light emitted from the second optical fiber to the O / E section, A first single-core ferrule for positioning the first optical fiber on the optical axis, and a second single-core ferrule for positioning the second optical fiber on the optical axis of the optical system
And the third optical fiber side end of the first optical fiber and the fourth optical fiber side end of the second optical fiber are bundled, and the optical axis of the first optical fiber and the optical axis of the second optical fiber are A first two-core ferrule for relative positioning, a first optical fiber side end of the third optical fiber and a second optical fiber side end of the fourth optical fiber bundled, and an optical axis of the third optical fiber And the second two-core ferrule for positioning the optical axis of the fourth optical fiber relative to each other, and a coupling part for coupling the first two-core ferrule and the second two-core ferrule. The optical axis alignment of the first optical fiber and the third optical fiber and the optical axis alignment of the second optical fiber and the fourth optical fiber are performed by a half holding portion, a coupling portion, and a coupling operation. Characterized in that it at the time.

As an invention having such various aspects,
According to a first aspect of the present invention, as an optical sensor, a certain optical system, a first optical fiber for inputting light to the optical system, and a pair of the first optical fiber and the output of the optical system are formed. A second optical fiber for receiving the emitted light, an optical signal processing circuit including an E / O unit, an O / E unit, and a signal processing unit; and a third unit for transmitting the light from the E / O unit to the first optical fiber. An optical fiber, a fourth optical fiber that relays light emitted from the second optical fiber to the O / E unit, and a first single-core holding unit that positions the first optical fiber on the optical axis of the optical system. And a second single-core holding unit for positioning the second optical fiber on the optical axis of the optical system;
A third optical fiber side end of the first optical fiber and a fourth optical fiber side end of the second optical fiber are bundled to perform relative positioning between the optical axis of the first optical fiber and the optical axis of the second optical fiber. 1, a second optical fiber holding end, a first optical fiber side end of the third optical fiber, and a second optical fiber side end of the fourth optical fiber, and the optical axis of the third optical fiber and the fourth The second two-core holding part for positioning the optical axis of the optical fiber relative to each other, the first two-core holding part and the second two-core holding part are connected, and the first optical fiber and the third Optical axis alignment of the second optical fiber and the fourth optical fiber
It is characterized by a joint part that can simultaneously align the optical axes of the optical fibers.By reducing the number of expensive ferrules, the man-hour for ferrule processing and the man-hour for optical fiber joining work are reduced. The optical sensor can be mass-produced simply and at low cost.

According to a second aspect of the present invention, as an optical sensor, a certain optical system, a first optical fiber for transmitting light to the optical system, and a pair of the first optical fiber and the optical system are formed. A second optical fiber for transmitting light from the first optical fiber, a lens for guiding the output light of the first optical fiber to the incident side of the optical system, and simultaneously guiding the output light of the optical system to the second optical fiber; An optical signal processing circuit comprising a unit, an O / E unit, and a signal processing unit; a third optical fiber that sends the light from the E / O unit to the first optical fiber; and an output light from the second optical fiber. A fourth optical fiber for relaying to the O / E unit, the optical system side end of the first optical fiber and the optical system side end of the second optical fiber are bundled, and the optical axis of the first optical fiber and the second Optical fiber relative to optical axis A third two-core holding portion for positioning, a third optical fiber side end of the first optical fiber and a fourth optical fiber side end of the second optical fiber are bundled, and an optical axis of the first optical fiber and a second A first two-core holding portion for positioning the optical axes of the optical fibers relative to each other, a first optical fiber side end of the third optical fiber, and a second optical fiber side end of the fourth optical fiber, The second two-core holding part that positions the optical axis of the third optical fiber and the optical axis of the fourth optical fiber relative to each other, the first two-core holding part, and the second two-core holding part Coupling the optical axes of the first optical fiber and the third optical fiber, and the second optical fiber and the fourth optical fiber.
It is characterized by a joint part that can simultaneously align the optical axes of the optical fibers.By reducing the number of expensive ferrules, the man-hour for ferrule processing and the man-hour for optical fiber joining work are reduced. The optical sensor can be mass-produced simply and at low cost.

According to a third aspect of the present invention, in the optical sensor according to the second aspect, the lens of the optical system is a first lens.
And a second GRIN lens for guiding the light emitted from the optical system to the incident position of the optical system, and a second GRIN lens for guiding the emitted light from the optical system to the second optical fiber position.

According to a fourth aspect of the present invention, as an optical sensor, a certain optical system, a first optical fiber for transmitting light to the optical system, and a pair with the first optical fiber are formed to form a pair. A second optical fiber for transmitting the light of
An optical signal processing circuit comprising a unit, an O / E unit, and a signal processing unit; a third optical fiber that sends the light from the E / O unit to the first optical fiber; and an output light from the second optical fiber. A fourth optical fiber for relaying to the O / E unit;
A third bundling the optical system side end of the first optical fiber and the optical system side end of the second optical fiber to position the optical axis of the first optical fiber and the optical axis of the second optical fiber relative to each other. A two-core holding portion, a third optical fiber side end of the first optical fiber and a fourth optical fiber side end of the second optical fiber are bundled, and an optical axis of the first optical fiber and an optical axis of the second optical fiber are bundled. A first two-core holding portion for performing relative positioning, and a first
The second two-core bundles the optical fiber side end of the fourth optical fiber and the second optical fiber side end of the fourth optical fiber, and positions the optical axis of the third optical fiber and the optical axis of the fourth optical fiber relative to each other. A holding unit, the first two-core holding unit and the second two-core holding unit are coupled, and the optical axes of the first optical fiber and the third optical fiber are aligned with each other.
And an optical axis of the fourth optical fiber, and an optical axis of the second optical fiber coincides with an incident light position coincident with the optical axis of the first optical fiber. It is characterized by having an outgoing light position that reduces the number of expensive ferrules, thereby reducing the man-hour for ferrule processing and the man-hour for optical fiber coupling work, and enabling an optical sensor to be manufactured simply and at low cost. Has the effect of mass production.

According to a fifth aspect of the present invention, in the optical sensor according to the first, second or fourth aspect, the first two-core holding portion is provided when the first optical fiber and the second optical fiber are inserted. The first optical fiber and the second optical fiber have one size enough to contact each other, and the center of gravity of the first optical fiber and the second optical fiber coincides with the center of the cross section of the holding portion. The second two-core holding portion has one hole having a size such that the third optical fiber and the fourth optical fiber are in contact with each other when the third optical fiber and the fourth optical fiber are inserted. In addition, the center of gravity of the cross section of the holding portion coincides with the center of gravity of the third optical fiber and the fourth optical fiber.

According to a sixth aspect of the present invention, there is provided an optical sensor according to the first, second or fourth aspect.
4. The first two-core holding portion and the second two-core holding portion described in No. 4 each have a concave and convex portion on a side surface, and the optical axis of the first optical fiber and the third
The coupling portion allows the convex and concave portions of the first two-core holding portion and the second and third optical fibers to coincide with each other so that the optical axis of the second optical fiber can coincide with the optical axis of the second optical fiber. The relative positions of the convex and concave portions of the core holding portion are fixed.

According to a seventh aspect of the present invention, n (> 1) belongs to the optical system according to any one of the first to sixth aspects.
Optical systems (first to n-th optical systems) and the k-th optical system (k
= 1 to n) (k1 = 1 to n) for transmitting light to the optical system
K2 (k2 = n), which forms a pair with the k1st optical fiber and transmits light from the kth optical system.
+1 to 2n) and n E / O units (first
To n-th E / O unit) and n O / E units (first to n-th O / E units)
/ E unit) and a signal processing unit, a k3 (k3 = 2n + 1 to 3n) optical fiber that sends the light of the kth E / O unit to the k1st optical fiber, The k4th (k4 = 3n + 1 to 4n) optical fiber for relaying the output light of the k2th optical fiber to the kth O / E section, and the optical signal processing circuit side end of the 2n optical fibers of the k1 and k2. Bundling, the k1 and k2 2
a first 2n-core holding unit for positioning the optical axes of the n optical fibers relative to each other; and an optical signal processing circuit side end of the 2n optical fibers k3 and k4, and the k-th optical fiber is bundled.
A second 2n-core holding unit that positions the optical axes of the 2n optical fibers 3 and k4 relative to each other;
The n-core holding unit and the second 2n-core holding unit are connected to each other, and the k-th and k-th 2n optical fibers are connected to the k-th and k-th optical fibers.
4 2n optical fibers are each constituted by a coupling portion capable of simultaneously aligning the optical axes.

According to an eighth aspect of the present invention, in the first 2n-core holding section according to the seventh aspect, when 2n optical fibers are inserted, the 2n optical fibers are at least connected to each other optical fiber. The second 2n-core holding section has a structure in which one hole is provided so as to be in contact with one, and the center of gravity of the 2n optical fibers coincides with the center of the cross section of the holding section. When the 2n optical fibers are inserted, the 2n optical fibers have at least one hole so as to be in contact with at least one of the other optical fibers, and 2n with respect to the center of the cross section of the second 2n core holding portion.
The relative positional relationship between the optical fibers corresponds to the relative positional relationship between the 2n optical fibers with respect to the center of the cross section of the first 2n-core holding portion.

According to a ninth aspect of the present invention, in the optical sensor according to the seventh aspect, the first 2n-core holding portion and the second
The two-core holding portion has a concave and convex portion on the side surface, and coincides with the optical axis of the k1th optical fiber and the optical axis of the k3th optical fiber and the optical axis of the k2th optical fiber and the optical axis of the k4th optical fiber. The relative positional relationship between the convex and concave portions of the first 2n-core holding portion and the convex and concave portions of the second 2n-core holding portion is fixed by the coupling portion so that the coincidence can be performed simultaneously.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a diagram showing a first embodiment of the optical sensor of the present invention. As shown in FIG. 1, the optical sensor includes a sensor unit including a polarizer 1, a quarter-wave plate 2, an electro-optic crystal 3, and an analyzer 4 on the optical axis from the light incident side, Optical fiber 8, GRIN lens (0.2
5) a first holder 6, a first single-core ferrule 7, a second optical fiber 8 ', and a second GRI on the polarizer 1 side end of the sensor unit corresponding to the first optical fiber 8.
N lens (0.25 pitch) 5 ′, second holder 6 ′, second single-core ferrule 7 ′ at the analyzer-side end of the sensor section of second optical fiber 8 ′, first optical fiber 8, An E / O circuit (not shown) composed of a first two-core ferrule 9 connected to an end of the second optical fiber 8 'opposite to the single-core ferrules 7, 7', and an E / O circuit (not shown) , An O / E circuit (not shown), a signal processing unit (not shown) composed of a signal processing circuit (not shown) for calculating an output result of the O / E circuit, and an optical signal of the E / O circuit. A third optical fiber 12 for transmitting light from the light receiving unit to the O / E circuit, a third optical fiber 12 ′ for transmitting light from the light receiving unit to the O / E circuit, the third optical fiber 12 and the fourth optical fiber 1.
2 ′ bundled optical fiber cable, an optical transmission unit composed of a second two-core ferrule 9 ′ at the end of the third optical fiber 12 and the fourth optical fiber 12 ′ on the light receiving / emitting section side, It comprises a two-core ferrule 9 and an optical axis alignment guide 10 for connecting the second two-core ferrule 9 '.

The first two-core ferrule 9 and the second two-core ferrule 9 'have the same configuration having one hole, and the two-core ferrule has a hole in which the two optical fibers are connected to each other. And the center of gravity of the two optical fibers coincides with the center of the two-core ferrule. The first two-core ferrule 9 and the second two-core ferrule 9 ′ are coupled in the same straight line by the optical axis alignment guide 10, and the optical axes of the two optical fibers are formed with the mechanical accuracy of the two-core ferrule shape. Matching can be performed simultaneously. For example, Nippon Electric Glass Co., Ltd.
And a square hole micro-capillary.

In the ferrule processing for integrating the two optical fibers and the two-core ferrule, the two optical fibers are inserted into the hole of the two-core ferrule, fixed with resin, and the end face of the optical fiber is mirror-polished together with the two-core ferrule. Then, the loss is minimized when the optical axes of the ferrule-processed optical fibers are aligned.

(Second Embodiment) FIG. 2 is a view showing a second embodiment of the optical sensor of the present invention. In FIG. 2, the first and second optical fibers 8 and 8 ′ or the first and second two-core ferrules 9 and 9 ′ are not clearly distinguished from each other and are not denoted by reference numerals. Since it is the same as the arrangement relationship, a clear code division is omitted. This is the same in FIGS. 3 and 4 described later. As shown in FIG. 2, the optical sensor according to this embodiment includes a polarizer 1, a phaser 20, and an analyzer 4 on the optical axis from the light incident side.
, A first optical fiber 8, a first GRIN lens (0.5 pitch) having an outer diameter much larger than the outer diameter of the first optical fiber, a second optical fiber 8 ', A second GRIN lens (0.5 pitch) 21 ′ having the same shape as the first GRIN lens;
Optical fiber 8 ', the first optical fiber 8 and the second
The third two-core ferrule 22 at the sensor-side end of the optical fiber 8 ′, the first two-core ferrule 9 on the opposite side of the first and second optical fibers 8, 8 ′ from the third two-core ferrule , An E / O circuit (not shown), an O / E circuit (not shown), and a signal processing circuit (not shown) for calculating an output result of the O / E circuit. A signal processing unit (not shown) for transmitting light from the E / O circuit to the light emitting unit;
Fourth optical fiber 1 for transmitting light from the light receiving section to a circuit
2 ′, an optical fiber cable 11 in which the third optical fiber 12 and the fourth optical fiber 12 ′ are bundled, and a second two-core ferrule at the light emitting / receiving section side end of the third optical fiber 12 and the fourth optical fiber 12 ′ 9 'and an optical axis alignment guide 10 for connecting the first two-core ferrule 9 and the second two-core ferrule 9'.

The first to third two-core ferrules have the same configuration having one hole, as in the first embodiment.
The hole of the two-core ferrule has a shape such that the two optical fibers are in contact with each other and the center of gravity of the two optical fibers coincides with the center of the two-core ferrule. The first two-core ferrule 9 and the second two-core ferrule 9 ′ are connected in the same straight line by the optical axis alignment guide 10, and the two-core ferrule 9 has the mechanical accuracy of the two-core ferrule shape.
The optical axes of the optical fibers can be simultaneously adjusted.

The third two-core ferrule and the first GR
The IN lens and the second GRIN lens are configured such that the center of the third two-core ferrule coincides with the midpoint of the first GRIN lens and the second GRIN lens. The exit position to the polarizer 1 and the entrance position from the analyzer 4 to the second GRIN lens coincide with a distance equal to the radius of the optical fiber from the outside of the corresponding GRIN lens.

(Third Embodiment) FIG. 3 is a diagram showing a third embodiment of the optical sensor according to the present invention. As shown in FIG. 3A, the optical sensor according to this embodiment includes a first right-angle mirror 31 and a modulation element 3 on the optical axis from the light incident side.
0, a sensor unit including a second right-angle mirror 31 ';
A first optical fiber 8, a second optical fiber 8 ′, a third two-core ferrule 22 at the sensor-side end of the first optical fiber 8 and the second optical fiber 8 ′, and a first optical fiber 8 and a second optical fiber 8 ′ A light emitting / receiving unit composed of a first two-core ferrule 9 on the opposite side of the third two-core ferrule of the optical fiber 8 ', an E / O circuit (not shown), and an O / E circuit (not shown) , A signal processing unit (not shown) composed of a signal processing circuit (not shown) for calculating an output result of the O / E circuit, and a third optical fiber for transmitting light of the E / O circuit to the light emitting unit 12, a fourth optical fiber 12 'for transmitting the light of the light receiving section to the O / E circuit, an optical fiber cable 11 in which the third optical fiber 12 and the fourth optical fiber 12' are bundled, and a third optical fiber 12. Receiving the fourth optical fiber 12 ' An optical transmission unit composed of a second two-core ferrule 9 'at the optical part side end, and an optical axis alignment guide 10 connecting the first two-core ferrule 9 and the second two-core ferrule 9'. Be composed.

The first to third two-core ferrules have the same configuration as in the first embodiment, and have the same configuration with one hole as shown in the enlarged view of FIG. In the hole of the two-core ferrule, the two optical fibers are in contact with each other,
The optical fiber has a shape such that the center of gravity of the two optical fibers coincides with the center of the two-core ferrule. The first two-core ferrule 9 and the second two-core ferrule 9 ′ are coupled in the same straight line by the optical axis alignment guide 10, and the optical axes of the two optical fibers are formed with the mechanical accuracy of the two-core ferrule shape. Matching can be performed simultaneously.

It should be noted that the third two-core ferrule, the first right-angle mirror 31 and the second right-angle mirror 31 '
The center of the core ferrule is configured such that the symmetry lines of the first right-angle mirror and the second right-angle mirror coincide with each other.
The outgoing position from the optical fiber 8 to the first right-angle mirror and the incident position from the second right-angle mirror to the second optical fiber 8 'are line-symmetric with respect to the center of the third two-core ferrule.

(Fourth Embodiment) FIG. 4 is a diagram showing a fourth embodiment of the optical sensor according to the present invention. As shown in FIG. 4, the optical sensor according to this embodiment has a total of four optical fibers of the optical sensor according to the first embodiment and the optical sensor according to the third embodiment. Optical axes are simultaneously aligned with the four-core optical fiber, ie, the signal processing-side ends of the first optical fiber and the second optical fiber of the optical sensor according to the first embodiment;
A first four-core ferrule for bundling the signal processing-side ends of the first optical fiber and the second optical fiber of the optical sensor according to the third embodiment; a third optical fiber and a third optical fiber of the optical sensor according to the first embodiment; 4, the sensor-side end of the optical fiber;
A second four-core ferrule for bundling the third optical fiber and the fourth optical fiber of the optical sensor according to the third embodiment on the sensor side, the first four-core ferrule and the second four-core ferrule The optical axis alignment guide 41 is combined.

As an example of the configuration of the four-core ferrule, as shown in FIG. 5, the ferrules are circular in cross section, square in hole shape, and arranged so that the center of each of the four-core optical fibers is located at the apex of the square. The four optical fibers of the four-core ferrule of the coupling partner also correspond to the four optical fibers at the time of coupling.
Line up at the same position so that the optical fiber and the optical axis of the core are aligned.

The hole shape of the cross section of the four-core ferrule may be any shape other than the square, and it is sufficient that four optical fibers are in contact with at least one other optical fiber in the hole, respectively. Ferrule has the same shape,
There is no problem if the order of the optical fibers corresponds.

(Fifth Embodiment) FIG. 6 is a diagram showing a fifth embodiment of the optical sensor according to the present invention. As shown in FIG. 6, the optical sensor according to this embodiment has a first two-core ferrule 64 having a circular outer shape and a second two-core ferrule 64 ′ having a circular outer shape in the optical sensor according to the first embodiment. Of the first optical fiber and the optical axis of the third optical fiber, and the optical axis of the second optical fiber coincides with the optical axis of the fourth optical fiber at the same time. A configuration in which the relative position of the convex portion 61 of the first two-core ferrule and the convex portion 61 'on the side surface of the second two-core ferrule is fixed by the optical axis alignment guide 63 having the rotation prevention guide 62 so that the rotation can be performed. Having.

Finally, as an electro-optic crystal whose composition is not limited, Bi ₁₂ SiO ₂₀ (B
SO), KDP, LiNbO ₃ having natural birefringence,
Alternatively, an electrode terminal 14, a lead wire 13, and an electrode are electrically connected to the electro-optic crystal 3 for voltage application by using LiTaO ₃ or the like, and a voltage to be measured is applied to the electrode terminal 14. ing. The polarizer 1 and the pre-analyzer 4
Uses a right angle beam splitter (PBS).

[0032]

As is apparent from the above description,
The present invention has an effect that by reducing the number of expensive ferrules, the man-hour for ferrule processing and the man-hour for optical fiber connection can be reduced, and mass production of optical sensors can be performed simply and at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an optical sensor according to a first embodiment of the present invention.

FIG. 2 is a configuration outline of an optical sensor according to a second embodiment of the present invention.

FIG. 3 is a configuration outline of an optical sensor according to a third embodiment of the present invention.

FIG. 4 is a configuration outline of an optical sensor according to a fourth embodiment of the present invention.

FIG. 5 is a schematic sectional view of an example of a 4-core ferrule.

FIG. 6 is a schematic diagram of a rotation-preventing projection of a two-core ferrule.

FIG. 7 is an outline of a configuration of a conventional optical voltage sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polarizer 2 λ / 4 plate 3 LiNbO3 crystal 4 Analyzer 5 GRIN lens (0.25 pitch) 6 Holder 7 Single-core ferrule (sensor side) 8 Optical fiber of light emitting part 9 2-core ferrule 10 Optical axis alignment guide (2 11 Optical fiber cable 12 Optical fiber of optical transmission section 13 Lead wire 14 Electrode terminal 20 Phaser 21 GRIN lens (0.5 pitch) 22 Receivable range 30 Modulator 31 Mirror 32 Core 33 Clad 40 4-core ferrule 41 Optical axis Alignment guide (for 4-core) 50 4-core ferrule hole 60 2-core ferrule hole 61 Ferrule protrusion 62 Rotation prevention guide 63 Optical axis alignment guide (with rotation prevention guide) 70 Sensor unit 71 Light emitting unit 72 Light receiving unit 73 Optical transmission unit 74 Split sleeve 75 Single core ferrule (transmission side) 76 Single core ferrule (Transmission end)

Claims (9)

[Claims] 1. An optical system, a first optical fiber for entering light into the optical system, a second optical fiber that forms a pair with the first optical fiber and receives light emitted from the optical system, An optical signal processing circuit including an / O unit, an O / E unit, and a signal processing unit; a third optical fiber that sends light from the E / O unit to the first optical fiber; A fourth optical fiber that relays the emitted light to the O / E unit, a first single-core holding unit that positions the first optical fiber on the optical axis of the optical system, and a fourth optical fiber that is positioned on the optical axis of the optical system. The second positioning the second optical fiber
, A third optical fiber end of the first optical fiber and a fourth optical fiber end of the second optical fiber are bundled, and an optical axis of the first optical fiber and an optical axis of the second optical fiber are bundled. A first two-core holding portion for performing relative positioning, a first optical fiber side end of the third optical fiber, and a second optical fiber side end of the fourth optical fiber, and the third optical fiber The second two-core holding part for positioning the optical axis relative to the optical axis of the fourth optical fiber; the first two-core holding part;
And a coupling part that can simultaneously perform optical axis alignment of the first optical fiber and the third optical fiber and optical axis alignment of the second optical fiber and the fourth optical fiber. An optical sensor comprising: 2. An optical system, a first optical fiber for transmitting light to the optical system, a second optical fiber for forming a pair with the first optical fiber and transmitting light from the optical system,
The light emitted from the first optical fiber is guided to the incident side of the optical system, and at the same time, the light emitted from the optical system is guided to the second optical fiber by a lens, an E / O unit, an O / E unit, and a signal processing unit. An optical signal processing circuit, a third optical fiber for sending the light of the E / O section to the first optical fiber, and a fourth optical fiber for relaying the emitted light of the second optical fiber to the O / E section. An optical fiber, the optical system side end of the first optical fiber and the optical system side end of the second optical fiber are bundled, and the optical axis of the first optical fiber and the optical axis of the second optical fiber are relatively positioned. A third two-core holding unit, a third optical fiber side end of the first optical fiber and a fourth optical fiber side end of the second optical fiber are bundled, and an optical axis of the first optical fiber and a second optical fiber Optical axis relative A first two-core holding portion for positioning, an end of the third optical fiber on the first optical fiber side and an end of the fourth optical fiber on the second optical fiber side, and an optical axis of the third optical fiber; And the second two-core holding part for positioning the optical axis of the fourth optical fiber relative to the first optical fiber, the first two-core holding part and the second two-core holding part, An optical sensor comprising: a coupling portion that can simultaneously perform optical axis alignment of an optical fiber and the third optical fiber and optical axis alignment of the second optical fiber and the fourth optical fiber. 3. The lens of the optical system according to claim 2, wherein the first GRIN lens guides the light emitted from the first optical fiber to the incident position of the optical system, and the light emitted from the optical system is a second optical fiber. 3. The optical sensor according to claim 2, comprising a second GRIN lens for guiding to a position. 4. An optical system and a first optical system for transmitting light to the optical system.
An optical fiber, a second optical fiber that forms a pair with the first optical fiber and transmits light from the optical system;
An optical signal processing circuit including an / O unit, an O / E unit, and a signal processing unit; a third optical fiber that sends light from the E / O unit to the first optical fiber; A fourth optical fiber for relaying the emitted light to the O / E section, the optical system side end of the first optical fiber and the optical system side end of the second optical fiber bundled, and the optical axis of the first optical fiber; A third two-core holding portion for positioning the optical axis of the second optical fiber relative to each other, a third optical fiber side end of the first optical fiber, and a fourth optical fiber side end of the second optical fiber, A first two-core holding portion for positioning the optical axis of the first optical fiber and the optical axis of the second optical fiber relative to each other; the first optical fiber side end of the third optical fiber; The second optical fiber The second two-core holding part for bundling the negative ends and positioning the optical axis of the third optical fiber and the optical axis of the fourth optical fiber relative to each other; the first two-core holding part; A two-fiber holding portion, and a coupling portion that can simultaneously perform optical axis alignment of the first optical fiber and the third optical fiber and optical axis alignment of the second optical fiber and the fourth optical fiber, The optical sensor according to claim 1, wherein the optical system has an incident light position coinciding with an optical axis of the first optical fiber and an outgoing light position coincident with an optical axis of the second optical fiber. 5. The first two-core holding section according to claim 1, wherein the first optical fiber and the second optical fiber are in contact with each other when the first optical fiber and the second optical fiber are inserted. The first optical fiber and the second optical fiber have the same center of gravity as the center of the cross section of the holding section, and the second two-core holding section has The third optical fiber and the fourth optical fiber have a single hole large enough to allow the third optical fiber and the fourth optical fiber to be in contact with each other when the third optical fiber and the fourth optical fiber are inserted. 5. The optical sensor according to claim 1, wherein a center of gravity of the optical sensor and a center of a cross-section of the holding portion coincide with each other. 6. 6. The first two-core holding portion and the second two-core holding portion according to claim 1, 2 and 4, have a concave and convex portion on a side surface, and have an optical axis of the first optical fiber and a third optical fiber. The coupling portion allows the convex and concave portions of the first two-core holding portion and the second and third optical fibers to coincide with each other so that the optical axis of the second optical fiber can coincide with the optical axis of the second optical fiber. The relative position of the convex and concave portions of the core holding portion is fixed.
The optical sensor according to any one of claims 2 and 4. 7. An n belonging to the optical system according to claim 1.
(> 1) optical systems (first to n-th optical systems) and a k1 (k1 = 1) for transmitting light to the k-th (k = 1 to n) optical systems
K2 (k) forming a pair with the k-th optical fiber and transmitting light from the k-th optical system.
2 = n + 1 to 2n) optical fibers, n E / O units (first to n-th E / O units) and n O / E units (first to n-th O / E units) An optical signal processing circuit including a signal processing unit; a k3 (k3 = 2n + 1 to 3n) optical fiber that transmits the light of the kth E / O unit to the k1th optical fiber; K4th (k4 = 3n + 1 to 4) relaying outgoing light to the kth O / E unit
n) and the optical signal processing circuit side ends of the 2n optical fibers of k1 and k2 are bundled, and the k1 and k2
(2) 2n optical fibers, a first 2n-core holding portion for relative positioning of the optical axes, and k3, k4 optical signal processing circuit-side ends of the 2n optical fibers are bundled to form the k3, k4 optical fibers. A second 2n-core holding unit for positioning the optical axes of the 2n optical fibers relative to each other;
And the second 2n-core holding portion are connected to each other, and the k-th and k-th 2n optical fibers and the k-th
An optical sensor comprising a coupling portion capable of simultaneously aligning each of 2n optical fibers of 3, k4. 8. The first 2n-core holding portion according to claim 7, wherein when the 2n optical fibers are inserted, each of the 2n optical fibers is at least one of the other optical fibers.
It has a configuration such that it has one hole in contact with each other and the center of gravity of the 2n optical fibers coincides with the center of the cross section of the holding section, and the second 2n-core holding section holds 2n optical fibers. The 2n optical fibers have at least one hole that makes contact with at least one other optical fiber when inserted, and the 2n optical fibers are positioned relative to the center of the cross section of the second 2n-core holding portion. 8. The optical sensor according to claim 7, wherein a positional relationship is equal to a relative positional relationship of 2n optical fibers with respect to a center of a cross section of the first 2n-core holding portion. 9. The first 2n-core holding part and the second two-core holding part according to claim 7, each of which has a concave and convex portion on a side surface, and has an optical axis of a k1th optical fiber and light of a k3th optical fiber. The coupling portion allows the convex and concave portions of the first 2n-core holding portion and the second 2n-core holding portion to coincide with each other so that the axes coincide with each other. The optical sensor according to claim 7, wherein the relative positional relationship between the convex and concave portions is fixed.