JP2002023015A - Method for manufacturing optical fiber connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical fiber connector, a method that brings high precision in the formation of a lens surface, and high quality as well as low cost of the product, and also that further simplifies the forming of the lens surface by eliminating a transfer body formed with a lens transfer surface. SOLUTION: A core 24 derived from the end of an optical fiber 23 having a thin diameter core 24 is inserted into a tubular connector body 22, in the core part of which a resin 25 is filled to bury the core 24. Then, from the front end of the connector body 22, a ultraviolet ray curing resin 26 is injected into the space 29 in front of the core derived end by means of an exclusive jig 30 such as a syringe, forming a reservoir 31 of the ultraviolet ray curing resin 26. Subsequently, the reservoir 31 thus formed is irradiated with an ultraviolet ray UV in the front part. The ultraviolet ray curing resin 26 is hardened by this irradiation and formed with a lens surface 27 in the front.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical fiber connector, and more particularly to a method for manufacturing an optical fiber connector in which a lens surface is formed at an end of an optical fiber having a core having a small diameter of about 5 to 10 microns. .

[0002]

2. Description of the Related Art In recent years, single-mode (SM) glass optical fibers have been widely used for long-distance trunk systems, and the construction of an information network using such optical fibers has been targeted. By the way, since the SM optical fiber has a very small core diameter of 5 to 10 microns, means for connecting or branching the optical fiber with high precision is required when laying the optical fiber.

As one of the means, there are an active alignment method and a passive alignment method for positioning a connection or branch end of an optical fiber.

In the former active alignment method, a light emitting or light receiving element is operated to perform optical coupling with an optical fiber, and while the output light of the light emitting element is taken into the optical fiber and monitored, the output light of the optical fiber is maximized. This is a method of adjusting the relative position of both. However, this method requires a lot of adjustment time,
It was difficult to reduce the cost of the product.

[0005] On the other hand, the latter passive alignment method is a method in which a light emitting or light receiving element is manufactured by high-precision processing so that it is not necessary to operate the element and monitor it by optical coupling. This method does not require element alignment, but requires precision of individual components of the element and requires high-precision processing, resulting in an increase in product cost.

[0006] In any of the above-described methods, if an attempt is made to connect or branch an optical fiber with high accuracy, the cost of the product is increased. Therefore, a high-precision optical fiber connector as shown in FIG. 1 was used.

In the optical fiber connector 1 shown in FIG. 1, an end of an SM type optical fiber 3 is arranged at the rear end of a tubular connector main body 2 made of metal or resin, and a core 4 derived from the end is connected to the connector main body. 2, the core portion of the connector body 2 is filled with a resin material 5 such as epoxy resin, and the core 4 is embedded. A space 6 in front of the core 4 of the optical fiber 3 embedded in the resin material 5 is provided at the front end of the connector body 2.
A small aspherical lens 8 having a lens surface 7 of a predetermined shape is fitted through the optical fiber 3, and the output light from the tip of the core of the optical fiber 3 is converted into parallel light by the aspherical lens 8.

[0008]

In the conventional optical fiber connector 1 shown in FIG. 6, a small aspherical surface is provided at the front end of the connector body 2 in order to make the output light from the tip of the optical fiber 3 parallel. It has a structure in which the lens 8 is fitted. As the aspheric lens 8, since the core diameter of the optical fiber 3 is as small as 5 to 10 microns, a lens having a diameter of about 1 mm is usually used.

When the aspherical lens 8 having a very small diameter of about 1 mm is to be fitted into the connector main body 2, the optical fiber 3 and the aspherical lens 8 inserted into the connector main body 2 are connected to each other. It is very difficult to align the optical axis, and there has been a problem that the quality and reliability are reduced due to the optical axis deviation and the cost of the product is increased.

[0010] To solve this problem, the present applicant has
For example, a high-precision optical fiber connector applicable to an optical fiber having a small core diameter such as an SM type optical fiber and a method of manufacturing the same have been proposed (Japanese Patent Laid-Open No. 9-15448).

As shown in FIG. 7, the optical fiber connector 11 has an end portion of an SM type optical fiber 13 disposed at a rear end of a cylindrical connector body 12 made of metal or resin, and a core 14 extending from the end portion. Is inserted into the connector main body 12, and a resin material 15 such as an epoxy resin is filled in a core portion of the connector main body 12 to bury the core 14.
Has a structure in which a lens surface 17 is integrally formed of an ultraviolet curable resin material 16 filled in a front portion of the core at the front end of the lens.

Further, as shown in FIG. 8 (a), the manufacturing method is such that a core 14 derived from an end of an optical fiber 13 having a small-diameter core 14 is inserted into the connector body 12, and the core leading end is Inject UV curable resin material 16 into the front part
After filling, the transfer body 20 having the lens transfer surface 19 formed thereon is pressed against the front surface of the ultraviolet curable resin material 16,
As shown in FIG. 2B, the ultraviolet curable resin material 16 is cured by irradiating ultraviolet rays UV transmitted through the transfer body 20, and the ultraviolet curable resin material 16 is hardened by the lens transfer surface 19.
The lens surface 17 is transferred to the front of the lens.

Since the lens surface 17 is formed integrally with the connector main body 12 by the ultraviolet curing resin material 16 as described above, the transfer of the lens surface 17 and the integration with the connector main body 12 can be performed, so that the lens surface 17 can be formed. It is possible to achieve simplification and high accuracy, high quality of products, and cost reduction.

However, in the manufacturing method described above, since the lens surface 17 is formed on the front surface of the ultraviolet curable resin material 16 injected and filled into the end of the connector main body 12, the transfer body 20 having the lens transfer surface 19 formed thereon is formed. Such a dedicated jig is required. In addition, an operation of pressing the transfer body 20 against the front surface of the ultraviolet curable resin material 16 is also necessary, and an improvement has been desired in that such an operation process becomes complicated.

Therefore, the present invention has been proposed in view of the above-mentioned points of improvement, and aims at improving not only the precision of forming the lens surface, the quality of the product, and the cost, but also the object of the present invention. It is another object of the present invention to provide a method of manufacturing an optical fiber connector which can further simplify the formation of a lens surface by eliminating the need for a transfer body having a lens transfer surface.

[0016]

According to a first aspect of the present invention, a core derived from an end of an optical fiber having a small diameter core is attached to a tubular connector body. After inserting the UV curable resin material into a space located in front of the core lead-out end to form a pool of the UV curable resin material, the UV curable resin material is cured by irradiating ultraviolet light, and the UV curable resin is cured. A lens surface is formed on the front surface of the material.

According to the first aspect of the present invention, after the ultraviolet curable resin material is injected into the space located in front of the core lead-out end in the connector main body to form the pool of the ultraviolet curable resin material,
By simply curing the UV-curable resin material by UV irradiation, it is possible to easily form a lens surface integrated with the connector body on the front surface of the UV-curable resin material. Not only can quality and cost be reduced, but a transfer body on which a lens transfer surface is formed becomes unnecessary, and the formation of a lens surface can be further simplified.

According to the first aspect of the present invention, after the lens surface is formed, while the transmitted wavefront of the lens surface of the ultraviolet curable resin material is monitored, the lens surface is irradiated with a short-wavelength ultraviolet beam based on the monitoring information. It is preferable that the lens surface is corrected to a shape having an optimum transmitted wavefront by performing non-contact etching (claim 2).

As described above, while monitoring the transmitted wavefront of the lens surface of the ultraviolet curable resin material, the lens surface is etched in a non-contact manner by irradiating a short-wavelength ultraviolet beam based on the monitoring information, whereby the optimum transmitted wavefront is obtained. Can be set as a target in real time, and alignment of the optical axis and adjustment of the lens surface can be easily performed.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail.

The optical fiber connector 21 manufactured in this embodiment has a structure as shown in FIG. That is,
At the rear end of the tubular connector body 22 made of metal or resin,
An end of the M-type optical fiber 23 is arranged, a core 24 derived from the end is inserted into the connector main body 22, and the core portion of the connector main body 22 is filled with a resin material 25 such as epoxy resin to form the core 24. Buried. At the front end of the connector body 22, a lens surface 27 is formed on the front surface of an ultraviolet curable resin material 26 filled so as to be joined to the core end surface of the optical fiber 23, and the output light from the core end of the optical fiber 23 is formed. Are collimated by the lens surface 27 as shown by the broken arrows in the figure. In the drawing, reference numeral 28 denotes a positioning flange integrally formed on the outer periphery of the connector main body 22.

The optical fiber connector 21, in particular, the lens surface 27 of the ultraviolet curable resin material 26 is formed by a method described below.

As shown in FIG. 1A, the connector body 22
The end of the optical fiber 23 is arranged at the rear end, and a core 24 derived from the end is inserted into the connector body 22 so that a resin material 2 such as epoxy resin
5 and a core 24 is prepared. The ultraviolet curable resin material 26 needs to be a material that has a property of being cured by irradiation with ultraviolet UV, has fluidity, and can be injected into a narrow space.

Then, as shown in FIG. 2B, the ultraviolet curable resin material 26 is injected into a space 29 located in front of the core leading end from the front end of the connector main body 22 by a special jig 30 such as a syringe. Pool 3 of cured resin material 26
Form one. By appropriately setting various conditions such as the injection amount of the ultraviolet curable resin material 26 and the surface tension, a pool portion 31 having a desired convex shape due to the surface tension of the ultraviolet curable resin material 26 is provided at the front end of the connector main body 22. Obtainable. For example, when the ultraviolet curable resin material 26 having a large surface tension is used, the convex shape has a small curvature. Conversely, when the ultraviolet curable resin material 26 having a small surface tension is used, the convex shape has a large curvature.

Thereafter, as shown in FIG. 2C, the front surface of the reservoir 31 of the ultraviolet curing resin material 26 formed at the front end of the connector main body 22 is irradiated with ultraviolet rays UV. The ultraviolet curing resin material 26 is cured by the irradiation of the ultraviolet light UV, and a lens surface 27 is formed on the front surface of the ultraviolet curing resin material 26.

In the above description, the ultraviolet curable resin material 26 is injected into the space 29 in the front end of the connector main body 22 with the front end of the connector main body 22 facing upward. Since it is shaped and has a surface tension of the ultraviolet curable resin material 26, the ultraviolet curable resin material 26 can be injected even when the front end of the connector main body 22 faces downward. In this case, the pool portion 31 of the ultraviolet curable resin material 26 has a convex shape having a larger curvature due to its own weight than when the front end of the connector main body 22 is directed upward. Therefore, when the convex lens surface 27 having a large curvature is formed, the ultraviolet curable resin material 2 is formed with the front end of the connector body 22 facing downward.
6 is preferable.

The lens surface 27 of the ultraviolet curable resin material 26
Is formed, if it is necessary to correct the lens surface 27 by adjusting the optical axis of the lens surface 27 or adjusting the lens surface 27, the following procedure may be performed. FIG.
Shows an example of an apparatus for correcting the lens surface 27.

First, as shown in FIG. 3, the optical fiber connector 21 manufactured as described above is positioned and fixed by appropriate means, and a laser oscillator 32 is disposed in front of the optical fiber connector 21. The half mirror 33 is arranged at the bottom. On the other hand, the optical fiber 23 extending from the rear end of the optical fiber connector 21 is branched and arranged in parallel with the optical fiber connector 21, and the output light from the tip of the optical fiber is parallelized in front of the branched optical fiber 34. A collimator lens 35 serving as light is arranged, and a camera 37 is arranged via a half mirror 36. In the figure, 3
8 is a laser oscillator 32 based on the output of the camera 37.
Is a processing controller that controls the data processing and executes desired processing.

The laser oscillator 32 includes, for example, 110-110.
An ultraviolet laser having a short wavelength of 220 nm is used as a light source.
excimer laser made of ArF having a short wavelength of
A fluorine laser having a short wavelength of nm is preferable, and a hydrogen laser or the like can be used. In addition, other than the laser oscillator, a device having a structure in which an ultraviolet lamp such as an ArF ultraviolet lamp is used as a light source to irradiate an ultraviolet beam can be used. When using a vacuum ultraviolet light source that absorbs a lot in the air, install the entire system in a container and
It is used after gas replacement with r gas or the like or exhaustion to a vacuum.

In the above configuration, first, the optical fiber 2
3, 34, a laser beam having a wavelength according to its use,
For example, red light [633 nm] or green light [543 nm]
A laser beam L from a light source such as He-Ne laser is introduced. In this way, the output light La emitted from the optical fiber 23 of the optical fiber connector 21 via the lens surface 27 of the ultraviolet curable resin material 26 is used as the measurement sample light, and the output light La emitted from the optical fiber 34 via the collimator lens 35. Lb is used as reference light to cause interference by the half mirrors 33 and 36, and the interference between the two lights La and Lb is captured by the camera 37. Here, by making the output light (reference light) Lb of the optical fiber 34 into parallel light by the collimator lens 35, it is determined whether or not the output light (measurement sample light) La from the optical fiber connector 21 is parallel light. Can be determined.

The imaging signal from the camera 37 is image-processed by the processing controller 38, and the transmitted wavefront of the lens surface 27 of the ultraviolet curing resin material 26 in the optical fiber connector 21 is monitored. This monitoring can be displayed on a screen on a display device (not shown) attached to the processing controller 38. In this way, while monitoring the transmitted wavefront of the lens surface 27 of the ultraviolet curing resin material 26 in the optical fiber connector 21, the short-wavelength ultraviolet laser Lo emitted from the laser oscillator 32 based on the control signal output from the processing controller 38. By etching the lens surface 27 in a non-contact manner to form a surface having an optimum transmitted wavefront, the lens surface 27 can be easily corrected by adjusting the optical axis of the lens surface 27 or adjusting the lens surface. Can be.

For measuring the wavefront of the lens surface 27, a Shack-Hartmann wavefront measuring device 39 can be used as shown in FIG. The Shack-Hartmann wavefront measuring device 39 is composed of a lens array in which a large number of microlenses are arranged, a camera for recording the respective image forming positions of the measurement light by the microlenses of the lens array, and the like. A microlens having a high spatial resolution or a wide dynamic range may be selected according to the shape of the measurement light beam.

The principle of operation of the Shack-Hartmann wavefront measuring device 39 is as follows.

First, a laser beam L is introduced as shown in FIG. In this way, the output light (measurement light) La emitted from the optical fiber 23 of the optical fiber connector 21 via the lens surface 27 of the ultraviolet curable resin material 26 is incident on the Shack-Hartmann wavefront measuring device 39 via the half mirror 33.
In the lens array in the Shack-Hartmann wavefront measuring device 39, the focal position of each micro lens forms a point image on the optical axis, and is recorded by a camera based on the image forming position of the output light (measurement light) La.

Here, the Shack-Hartmann wavefront measuring device 3
In No. 9, since the imaging position of the microlens is set in advance based on the required reference data of the lens surface, the wavefront is measured from the difference between the imaging position based on the reference data and the imaging position of the measurement light. . The shift of the imaging position (shift amount and shift direction) corresponds to the inclination of the wavefront, and the processing controller 38 monitors the transmitted wavefront of the lens surface 27 of the ultraviolet curing resin material 26 in the optical fiber connector 21.

As described above, while monitoring the transmitted wavefront of the lens surface 27 of the ultraviolet curable resin material 26 in the optical fiber connector 21, the short wavelength light emitted from the laser oscillator 32 based on the control signal output from the processing controller 38. The lens surface 27 is etched in a non-contact manner with an ultraviolet laser Lo to form a surface having an optimum transmitted wavefront, thereby easily correcting the lens surface 27 such as adjusting the optical axis of the lens surface 27 and adjusting the lens surface. Can be performed.

FIG. 5A shows a connection state between the above-described one optical fiber connector 21 and another optical fiber connector 41 having substantially the same structure. The other optical fiber connector 41 has a connecting portion 40 extending a front portion of the ultraviolet curing resin material 46 of the connector main body 42 as shown in FIG. By inserting one optical fiber connector 21 into the connecting portion 40 of the other optical fiber connector 41,
The two optical fibers 23 and 43 are coaxially connected via parallel light between the lens surfaces 27 and 47.

FIG. 5B shows a connection state between the optical fiber connector 21 and the light emitting or receiving element 51. As shown in the figure, the transmitter or the receiver 52 has a connecting portion 50 at a mounting portion of the built-in light emitting or light receiving element 51. By inserting the optical fiber connector 21 into the connecting portion 50 of the transmitter or the receiver 52, the optical fiber 2
3 is optically connected to the light emitting or light receiving element 51 via the parallel light on the lens surface 27.

[0039]

According to the present invention, after the ultraviolet curable resin material is injected into the space located in front of the core lead-out end in the connector main body to form the pool of the ultraviolet curable resin material, the ultraviolet light is irradiated by ultraviolet light. Just by curing the cured resin material,
The lens surface integrated with the connector main body can be easily formed on the front surface of the ultraviolet curable resin material, so that not only the lens surface can be formed with higher precision, the product quality can be reduced, and the cost can be reduced. A dedicated jig such as a transfer body having a transfer surface is not required, and the formation of the lens surface can be further simplified.

[Brief description of the drawings]

FIG. 1 is a view for explaining an embodiment of a method for manufacturing an optical fiber according to the present invention, in which (a) is a cross-sectional view showing a connector body in which a core of an optical fiber is embedded in a resin material, and (b) is a cross-sectional view. FIG. 4A is a cross-sectional view illustrating a state in which an ultraviolet curable resin material is injected into a connector main body, and FIG. 4C is a cross-sectional view illustrating a state in which the ultraviolet curable resin material in FIG.

FIG. 2 is a sectional view showing an optical fiber connector manufactured by the manufacturing method of the present invention.

FIG. 3 is a schematic configuration diagram showing an example of an apparatus for correcting a lens surface in an optical fiber connector manufactured by the method of the present invention.

FIG. 4 is a schematic configuration diagram showing another example of an apparatus for correcting a lens surface in an optical fiber connector manufactured by the method of the present invention.

5A and 5B are views for explaining an example of use of the optical fiber connector of the present invention, wherein FIG. 5A is a cross-sectional view showing a case where optical fibers are connected to each other, and FIG. FIG.

FIG. 6 is a sectional view showing a conventional example of an optical fiber connector.

FIG. 7 is a sectional view showing an optical fiber connector previously proposed by the present applicant.

FIG. 8 is a cross-sectional view illustrating a state in which the connector body is filled with an ultraviolet curable resin material, for illustrating a method of manufacturing an optical fiber connector previously proposed by the present applicant.
(B) is a cross-sectional view showing a state where the lens surface is transferred to the front surface of the ultraviolet curable resin material by the transfer body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Optical fiber connector 22 Tubular connector main body 23 Optical fiber 24 Core 26 Ultraviolet curing resin material 27 Lens surface 29 Space part 31 Pool part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01S 5/022 H01L 31/02 C (72) Inventor Takahisa Mineno 2-6 Yamadaoka, Suita-shi, Osaka Osaka University Laser Fusion Research Center F-term (reference) 2H036 QA18 QA19 QA27 QA28 QA45 QA47 2H037 AA01 BA03 BA12 BA32 CA13 DA03 DA04 DA05 DA06 DA13 DA15 5F041 EE04 EE12 FF14 5F073 AB28 FA06 5F088 BA16 BB01 JA16

Claims (2)

[Claims] 1. A core derived from an end of an optical fiber having a small-diameter core is inserted into a cylindrical connector body, and an ultraviolet curing resin material is injected into a space located in front of the core leading end, and the ultraviolet light is injected. A method of manufacturing an optical fiber connector, comprising: forming a pool of a cured resin material, curing the ultraviolet-cured resin material by irradiating ultraviolet rays, and forming a lens surface on a front surface of the ultraviolet-cured resin material. 2. After forming the lens surface, while monitoring the transmitted wavefront of the lens surface of the ultraviolet curable resin material, the lens surface is etched in a non-contact manner by irradiating a short wavelength ultraviolet beam based on the monitoring information. 3. The method of manufacturing an optical fiber connector according to claim 2, wherein said lens surface is corrected to a shape having an optimum transmitted wavefront.