JPH08304666A - Fixing method for optical waveguide and optical fiber and fixing device therefor - Google Patents

Abstract

PURPOSE: To provide a fixing method for an optical waveguide and optical fibers which minimizes the thermal deterioration applied on UV curing resins and adhesives and a fixing device therefor. CONSTITUTION: The optical fiber 1 for incidence and the optical fiber 7 for exit are respectively butted against the incident end face and exit end face of the optical waveguide 2 in the state of aligning their optical axes and the uncured UV curing resins packed into their respective butt parts are simultaneously irradiated with UV rays, by which the UV curing resins are cured and the optical fiber 1 for incidence and the optical fiber 7 for exit are respectively fixed to the incident end face and exit end face of the optical waveguide 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide and an optical fiber fixing method for directly connecting an end face of the optical fiber to the optical waveguide, and a fixing device therefor.

[0002]

2. Description of the Related Art Various optical functional devices using an optical waveguide formed on a substrate have been developed. On the other hand, application fields of optical transmission lines using optical fibers such as optical fiber communication and optical fiber sensors are also expanding. An optical waveguide formed on a substrate when an optical signal sent through an optical fiber is processed by an optical functional device formed on the substrate, or conversely when an optical signal output from the substrate is transmitted by an optical fiber. It is essential to optically couple the optical fiber with the optical fiber.

One of the methods of optically coupling the optical waveguide and the optical fiber is a method of connecting using an adhesive such as a fluorinated epoxy type or a fluorinated epoxy acrylate type. In this method, the end faces of the optical waveguide and the end face of the optical fiber to be optically coupled to each other are opposed to each other, the optical axis is adjusted so that the optical coupling efficiency is maximized between them, and an optical adhesive is applied between both end faces. By filling and hardening this, the optical coupling of both is achieved. It usually takes several hours to several days until the optical adhesive is completely cured. In addition, during this period, the fixed part between the end face of the optical waveguide and the end face of the optical fiber must be kept still so that vibration or the like is not applied to the fixed part. Is very bad.

Therefore, in order to shorten the curing time of the optical adhesive, a method of using an ultraviolet curable resin instead of the optical adhesive has been proposed. In this method, as shown in FIG. 5 (a), first, an optical waveguide 2 is formed at the end of an optical fiber 1 for incidence.
A fixed block 3 made of glass, ceramics, resin, or the like is attached to increase the area of adhesion with the fixed block 3. Fixed block 3
Of the optical waveguide 2 held by the optical waveguide holding stage 11 is held by the optical fiber terminal holding stage 10 capable of moving in at least the XYZ axis directions. The optical fiber 1 for incidence and the optical waveguide 2 are aligned so as to oppose each other at the end.

In the above optical axis alignment, the light from the light source 13 is incident on the optical fiber 1 for incidence on the optical waveguide 2, and the light emitted from the other side of the optical waveguide 2 is received by the optical fiber 4 for emission measurement. An optical power meter 14 installed at the other end of the optical fiber 4 measures the light intensity of the optical fiber 4 and moves the optical fiber terminal holding stage 10 in each of the XYZ axis directions so that the maximum light intensity is obtained. Make a match.

After completion of the optical axis alignment, as shown in FIG. 5B, the uncured ultraviolet curable resin 5 pre-filled in the abutting portion between the end portion of the incident optical fiber 1 and the optical waveguide 2.
Then, ultraviolet rays are irradiated by an ultraviolet ray irradiation lamp 6 which is an ultraviolet ray irradiation source to cure the ultraviolet ray curable resin 5, and the incident optical fiber 1 and the optical waveguide 2 are bonded and fixed.

Next, in place of the optical fiber 4 for emission measurement, as shown in FIG. 5C, the end portion of the original optical fiber 7 for emission to be optically coupled to the optical waveguide 2 is connected to the optical fiber terminal holding stage 12. The optical fiber 7 for emission and the optical waveguide 2 are aligned so as to oppose each other at the end of the optical waveguide 2. In the above optical axis alignment, as shown in FIG. 5D, light is made incident on the optical waveguide 2 from the optical fiber 1 for incidence fixed to the optical waveguide 2 by the ultraviolet curing resin 5 and is emitted from the other side of the optical waveguide 2. Optical power meter 14 installed at the other end of optical fiber 7
Then, the light intensity is measured, and the stage 12 is moved in each of the XYZ axis directions so that the maximum light intensity is obtained, and the optical axis is aligned.

After completion of the optical axis alignment, as shown in FIG. 5 (e), the uncured ultraviolet curable resin 5 pre-filled in the abutting portion between the end portion of the outgoing optical fiber 7 and the optical waveguide 2.
In the same manner as in FIG. 5B, the ultraviolet curable resin 5 is cured by irradiating the ultraviolet ray, and the output optical fiber 7 and the optical waveguide 2 are bonded and fixed as shown in FIG. The curing time of the ultraviolet curable resin 5 is usually several minutes to 5 minutes at one end, which is significantly faster than that of the conventionally used optical adhesive and the working efficiency is greatly improved.

[0009]

As described above, by using the ultraviolet curable resin as the adhesive, the work of fixing the abutting portion of the optical waveguide and the optical fiber has been remarkably improved in efficiency. There is another problem.

That is, in the above method, the uncured UV curable resin 5 is cured by irradiating the joint between the end of the incident optical fiber 1 and the optical waveguide 2 with ultraviolet light, and then the emitted light is separately emitted. The uncured ultraviolet curable resin 5 at the abutting portion between the end portion of the fiber 7 and the optical waveguide 2 is also irradiated with ultraviolet rays to be cured. That is, the ultraviolet rays are irradiated again. The incident optical fiber 1 which is first cured by this second irradiation
The adhesive used to fix the end portion of the optical fiber 1 to the ultraviolet curable resin 5 or the fixed block 3 at the abutting portion of the end portion of the optical waveguide 2 with the optical waveguide 2 is directly heated by the heat of the ultraviolet irradiation lamp 6, or It is exposed to the heat of heat conduction transmitted through the optical waveguide 2, causing thermal deterioration.

This thermal deterioration has almost no effect on the appearance and the optical effect in the initial stage, but if it is used for a long period of time, it deteriorates with time, and for example, the optical axis changes at the abutting portion. And other problems occur. Therefore, there is a problem in the above method in which the thermal load is applied again to one of the butted portions.

The present invention solves the above-mentioned problems and eliminates the heat deterioration given to the adhesive for fixing the end portion of the optical fiber to the ultraviolet curable resin used for coupling the end portion of the optical fiber and the optical waveguide or the fixing block. It is an object of the present invention to provide a method of fixing a minimized optical waveguide and an optical fiber and a fixing device therefor.

[0013]

The present invention has the following means in order to solve the above problems.

In the fixing method of the optical waveguide and the optical fiber according to the first aspect of the present invention, the incident optical fiber and the outgoing optical fiber are butted to the incident end face and the outgoing end face of the optical waveguide, respectively, with their optical axes aligned. , Irradiating the uncured ultraviolet curable resin filled in the respective butting portions with ultraviolet rays at the same time to cure the uncured ultraviolet curable resin to fix the incident optical fiber and the outgoing optical fiber to the optical waveguide. It is characterized by

According to a second aspect of the present invention, in the apparatus for fixing an optical waveguide and an optical fiber, an optical waveguide terminal holding an optical waveguide and an optical fiber terminal holding optical fiber terminals arranged on both sides of the optical waveguide stage are held. Equipped with a stage,
The optical waveguide stage and the optical fiber terminal holding stage are relatively movable in each of the X-axis, Y-axis, and Z-axis directions, and the optical waveguide held by the optical waveguide stage and the optical fiber are held. It is characterized by further comprising an ultraviolet irradiation source capable of simultaneously irradiating ultraviolet rays to the uncured ultraviolet curable resin filled in the abutting portions with the respective optical fiber terminals held on the terminal holding stage.

[0016]

According to the method of fixing the optical waveguide and the optical fiber of the present invention, the state in which the optical axes of the incident optical fiber and the outgoing optical fiber are aligned with the incident end face and the outgoing end face of the optical waveguide, respectively. Butt, the uncured UV curable resin filled in each butted portion is simultaneously irradiated with UV rays to cure the UV curable resin and fix the incident optical fiber and the outgoing optical fiber to the optical waveguide. Since the ultraviolet curable resin filled in the butted portion is not irradiated with the ultraviolet ray twice, the thermal deterioration of the ultraviolet curable resin can be minimized. In addition, the heat load applied to the adhesive used for the fixing block made of glass, ceramic, resin, etc. fixed to the end of the optical fiber can be minimized once. Therefore, it is possible to form the fixed portion of the optical waveguide and the optical fiber, which has less deterioration with time of the ultraviolet curable resin and the adhesive and is excellent in optical stability.

According to the optical waveguide and optical fiber fixing device of the second aspect of the present invention, the optical waveguide terminal for holding the optical waveguide and the optical fiber terminal for holding the optical fiber terminals arranged on both sides of the optical waveguide stage. A holding stage is provided, and the optical waveguide stage and the optical fiber terminal holding stage are relatively movable in the respective directions of the X axis, the Y axis, and the Z axis, and the optical waveguide held by the optical waveguide stage. The optical waveguide stage is further provided with an ultraviolet irradiation source capable of simultaneously irradiating ultraviolet rays to the uncured ultraviolet curable resin filled in the abutting portions with the respective optical fiber terminals held by the optical fiber terminal holding stage. The optical axis of the optical waveguide held by the optical fiber and the optical axis of each optical fiber held by the optical fiber terminal holding stage are set to a known light source and a known optical power. It can be easily matched by using a meter.

Further, since the uncured ultraviolet curable resin filled in the abutting portions of the optical waveguide whose optical axes are aligned with each other and the optical fibers which are abutted at both ends thereof can be simultaneously irradiated with ultraviolet rays, the abutting portions can be simultaneously irradiated. It is possible to minimize the irradiation of ultraviolet rays to the ultraviolet ray curable resin used for the abutting part of the optical waveguide and the optical fiber and the adhesive used to fix the optical fiber to the fixing block. It is possible to minimize the heat deterioration generated by the heat load of 1, and to manufacture the fixed portion of the optical waveguide and the optical fiber that is less deteriorated with time and has optical stability.

[0019]

The present invention will be described below in detail with reference to examples. The same parts as those of the conventional one are designated by the same reference numerals and detailed description thereof will be omitted.

A method of fixing an optical waveguide and an optical fiber and a fixing device therefor according to the present invention will be described with reference to FIGS. 1 to 4. In FIGS. 1 to 4, 10 is an optical fiber terminal holding stage that holds the end portion of the optical fiber 1 for incidence and is movable in each of the XYZ axes directions, and 11 is an optical waveguide holding that holds the optical waveguide 2. The stage 12 is an optical fiber terminal holding stage that holds the end of the outgoing optical fiber 7 and is movable in each of the XYZ axis directions. 13 is LE
D light source, 14 is an optical power meter. Reference numeral 15 is a controller for the optical fiber terminal holding stages 10 and 12 on the X axis,
It controls an XYZ axis drive source 17 (shown in FIG. 4 described later) for moving in the Y axis direction and the Z axis direction, respectively.

In FIG. 2, 6 is an ultraviolet irradiation lamp,
A plurality of ultraviolet irradiation lamps 6, 8 in this embodiment.
One end of the light guide 16 for transmitting ultraviolet rays of the book is collectively connected. The other end of each light guide 16 for transmitting ultraviolet light is guided to the optical waveguide holding stage 11. The other ends of the eight ultraviolet light guides 16 are fixed to predetermined positions by clamps or the like not shown.

In the present embodiment, the light guides 16 for transmitting ultraviolet rays are respectively provided on both ends of the optical waveguide 2 in the vertical direction.
8 pieces each, one on each side of the left and right sides
Book is provided. In FIG. 1, the ultraviolet irradiation lamp 6, the eight ultraviolet light guides 16 and the XY are shown for the sake of illustration.
The Z-axis drive source 17 is omitted. XYZ axis drive source 17
Is an optical fiber terminal holding stage 10, as shown in FIG.
The reference numeral 17A is an X-axis drive body, 17B is a Y-axis drive body, and 17C is a Z-axis drive body. Each of the driving bodies 17A, 17B and 17C is composed of, for example, a piezoelectric element, and these are integrally coupled. The amount of movement in each axial direction is adjusted by the voltage.
Reference numeral 17D is a power supply line for supplying power to each piezoelectric element.

A method of fixing the optical fiber 1 and the optical fiber 7 to the optical waveguide 2 with the optical waveguide and optical fiber fixing device configured as described above will be described below. A fixed block 3 made of glass is attached to the ends of the incident optical fiber 1 and the outgoing optical fiber 7 to widen the bonding area with the optical waveguide 2. The fixed block 3 is provided with an optical fiber insertion hole substantially equal to the outer diameter of the optical fiber 1 (optical fiber 7), and the optical fiber 1 (optical fiber 7) is inserted into the optical fiber insertion hole. It is fixed by adhesion. Fixed block 3 and optical fiber 1
The end surface of the (optical fiber 7) is mirror-polished to form a joint end surface. The entrance end face and the exit end face of the optical waveguide 2 are also mirror-polished to form the joining end face like the joining end face of the optical fiber 1 (optical fiber 7).

First, the optical waveguide 2 is held by the clamp 18 on the optical waveguide holding stage 11. 19 is a clamp tightening screw. The end of the incident optical fiber 1 having the fixed block 3 mounted on the end thereof is clamped to the optical fiber terminal holding stage 10 so as to face one end of the optical waveguide 2 held by the optical waveguide holding stage 11. 18 and clamp tightening screw 19. Further, the end portion of the outgoing optical fiber 7 on which the fixed block 3 is mounted so as to face the other end portion of the optical waveguide 2 is held on the optical fiber terminal holding stage 12 by the clamp 18 and the KUMP tightening screw 19. The gap between the end face of the optical waveguide 2 and the end faces of the optical fibers 1 and 7 is set to, for example, about 5 μm, and the butt portion is filled with the uncured liquid ultraviolet curable resin 5.

In the above state, as shown in FIG.
The light of the ED light source 13 is made incident on the optical waveguide 1 from the incident optical fiber 1, and the light emitted from the other side of the optical waveguide 2 is received by the emitting optical fiber 7, and is installed at the other end of the optical fiber 7. The optical power meter 14 measures the light intensity, and the optical fiber terminal holding stages 10 and 12 are moved in the XYZ axis directions so that the maximum light intensity is obtained, and the optical axes are aligned.

After the alignment of the optical axes is completed, as shown in FIG. 3B, the end portion of the optical fiber 1 for incidence and the optical waveguide 2 and the end portion of the optical fiber 7 for emission and the optical waveguide 2 are joined. At the same time, the uncured ultraviolet curable resin 5 filled in the butted portion is irradiated with the ultraviolet light emitted from the ultraviolet irradiation lamp 6 through the ultraviolet transmission light guide 16.
As described above, the uncured ultraviolet curable resin 5 is simultaneously cured, and the incident optical fiber 1 and the outgoing optical fiber 7 and the optical waveguide 2 are bonded and fixed to form an optical waveguide as shown in FIG. The fixed part of the optical fiber is formed.

In the above embodiment, the ultraviolet rays emitted from one ultraviolet irradiation lamp are simultaneously emitted from the terminals of a plurality of ultraviolet transmission light guides, but the number of ultraviolet irradiation lamps is not limited to one. Alternatively, a plurality of ultraviolet irradiation lamps may be used. Instead of using the light guide for transmitting ultraviolet rays, ultraviolet rays may be directly irradiated to a predetermined place by a plurality of ultraviolet irradiation lamps.

Further, in the present invention, the simultaneous irradiation with ultraviolet light means that the uncured ultraviolet curable resin is cured almost at the same time, and the temperature of the first irradiation portion is completely lowered with a difference of several seconds to several tens of seconds. It is possible that the next irradiation is performed before the treatment. Furthermore, a lens for condensing light may be provided on the tip side of the light guide for transmitting ultraviolet light. By doing so, the ultraviolet rays are condensed and irradiated by the abutting portion of the optical waveguide and the optical fiber. As a result, the portion other than the abutting portion of the optical waveguide and the clamp are not irradiated, so that the influence of the thermal expansion of the optical waveguide and the clamp is suppressed, and the deviation of the optical axis between the optical waveguide and the optical fiber can be further prevented.

[0029]

As described above, according to the method of fixing the optical waveguide and the optical fiber of the first aspect of the present invention, the incident optical fiber and the outgoing optical fiber are respectively provided on the incident end face and the outgoing end face of the optical waveguide. Are abutted with their optical axes aligned, and the uncured ultraviolet curable resin filled in each abutting part is simultaneously irradiated with ultraviolet light to be cured, and the incident optical fiber and the outgoing optical fiber are fixed to the optical waveguide. Therefore, after the ultraviolet curable resin for fixing the end face of the optical waveguide and the end portion of the optical fiber is cured, the ultraviolet curable resin is not irradiated with ultraviolet rays again, so that the ultraviolet curable resin is less likely to be thermally deteriorated. Also, glass, ceramic,
Since the heat load given to the adhesive used to fix the end of the optical fiber to the fixing block composed of resin etc. can be done at a minimum once, the above-mentioned UV curable resin and the adhesive can be used over time. Deterioration can be reduced, and an optical waveguide and an optical fiber fixing portion having optical stability can be formed.

According to the optical waveguide and optical fiber fixing device of the second aspect of the present invention, the optical waveguide terminal holding the optical waveguide and the optical fiber terminal holding the optical fiber terminals arranged on both sides of the optical waveguide stage. Since a holding stage is provided and the optical waveguide stage and the optical fiber terminal holding stage are movable relative to each other in the X-axis, Y-axis, and Z-axis directions, the optical axes of the optical waveguide and each optical fiber are It can be easily matched by using a known light source and a known optical power meter.

Further, since the uncured ultraviolet curable resin filled in the abutting portions of the optical waveguides whose optical axes are aligned with each other and the optical fibers abutting on both ends thereof can be simultaneously irradiated with the ultraviolet rays, any of the abutting operations can be performed. It is possible to minimize the irradiation of ultraviolet rays to the part,
An optical waveguide that can minimize the thermal deterioration generated by the heat load of the ultraviolet curable resin or adhesive used for the fixing part of the optical waveguide and the optical fiber, has little deterioration with time, and has optical stability. The manufacturing of the fixed part of the optical fiber becomes easy.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an apparatus used for a method of fixing an optical waveguide and an optical fiber of the present invention.

2 is an enlarged perspective view of a part of the device of FIG. 1. FIG.

FIG. 3 is an explanatory view showing a part of steps of a method for fixing an optical waveguide and an optical fiber according to the present invention.

FIG. 4 is an explanatory diagram showing a part of the apparatus shown in FIG.

FIG. 5 is an explanatory view showing a part of steps of a conventional method for fixing an optical waveguide and an optical fiber.

[Explanation of symbols]

 1 Optical Fiber for Input 2 Optical Waveguide 3 Fixed Block 5 Ultraviolet Curing Resin 6 Ultraviolet Irradiation Lamp 7 Optical Fiber for Output 10 Optical Fiber Terminal Holding Stage 11 Optical Waveguide Holding Stage 12 Optical Fiber Terminal Holding Stage 13 LED Light Source 14 Optical Power Meter 16 Ultraviolet transmission light guide 17 XYZ axis drive source

Front page continued (72) Inventor Shiro Nakamura 2-6-1, Marunouchi Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Naoki Nakao 1-1-6 Uchiyuki-cho, Chiyoda-ku, Tokyo Nihon Telegraph Telephone Co., Ltd. (72) Inventor Kazuki Kudo 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Akira Morinaka 1-1-6 Uchiyuki-cho, Chiyoda-ku, Tokyo Nihonhon Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. An uncured UV-curing resin filled in an abutting end face and an outgoing end face of an optical waveguide, respectively, with an incident optical fiber and an outgoing optical fiber abutting each other with their optical axes aligned with each other. A method for fixing an optical waveguide and an optical fiber, wherein the uncured ultraviolet curable resin is cured by simultaneously irradiating it with ultraviolet rays to fix the incident optical fiber and the outgoing optical fiber to the optical waveguide. 2. An optical waveguide stage for holding an optical waveguide, and an optical fiber terminal holding stage for holding optical fiber terminals arranged on both sides of the optical waveguide stage, the optical waveguide stage and the optical fiber terminal holding stage. Is relatively movable in each of the X-axis, Y-axis and Z-axis directions, and the optical waveguide held by the optical waveguide stage and the respective optical fiber terminals held by the optical fiber terminal holding stage An apparatus for fixing an optical waveguide and an optical fiber, further comprising an ultraviolet ray irradiating source capable of simultaneously irradiating ultraviolet rays to an uncured ultraviolet ray curable resin filled in a butting portion of the optical waveguide.