JP2004317927A - V-groove pedestal setting for coated optical fiber connection and method for assembling coated optical fiber connection tool using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a structure which deforms in the same direction after being used for a long time to have small variation in connection loss, and is not liable to be displaced by external pressure generated by vibration or a shock. <P>SOLUTION: Disclosed is a V-groove pedestal setting 10 in integrated structure having a V groove 11 in which two coated optical fibers to be made to abut against each other are held, and the V groove 11 consists of a small V groove 11a provided in the center of the setting and large V grooves 11b which linearly connect with both sides of the small V groove 11a; and the small V groove 11a holds an optical fiber 5 whose coating is removed and the large V grooves 11b hold coated optical fibers 5 having coating. The depths of the small V groove 11a and large V grooves 11b are so set that the optical fiber 5 held in the small V groove 11a and the coated optical fibers 5 held in the large V grooves are concentric with each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical fiber connection technique. More specifically, the present invention relates to a V-groove pedestal for connecting an optical fiber core and an assembling method of an optical fiber core connecting jig using the same.
[0002]
[Prior art]
Fiber polishing has been used in the laying of optical communications, which is the center of the information industry in recent years, and is one of the important tasks indispensable in laying optical fiber networks to handle the ever-increasing traffic. One.
In particular, a connector plays an important role in a subscriber system, and a sharp increase in fiber polishing performed during ferrule polishing is expected.
[0003]
This connector plays an important part in compensating for reliability and economy in optical communication services to individual subscribers.
When the fiber is polished, cracks occur in the polished end face unless the fiber is completely fixed.
Therefore, as shown in FIG. 4, the optical fiber is completely fixed to the ferrule by applying an adhesive also to the end face of the ferrule (see Non-Patent Documents 1 and 2).
[0004]
That is, as shown in FIG. 4, a connection description diagram of a conventional connector, a ferrule 02 having two fitting pins 01 protruding from an end face, and two fitting pin holes into which these fitting pins 01 are inserted. The fibers 05 and 06, whose coating has been removed in advance, are inserted into the ferrules 04 provided on the end surfaces, respectively, and are completely fixed with the adhesive 07. By inserting the fitting pin 01 into the fitting pin hole 03, the fibers 05 and 06 are butted coaxially, and the ferrules 02 and 04 are fixed to each other by a leaf spring 08.
[0005]
As shown in FIG. 5, the ferrules 02 and 04 include a single core type and a multi-core type.
As described above, conventionally, when a connector is used to connect a fiber, the fiber 05, 06 and the ferrules 02, 04 are bonded and then polished, so that a single fiber cannot be taken out after polishing.
Further, in the conventional ferrules 02 and 04, as shown in FIG. 4, fibers 05 and 06 are set, bonded and polished, and the shafts are aligned using the fitting pins 01.
[0006]
For this reason, unless the clearance between the fibers 05 and 06 and the fitting pin hole 03 is secured to about 1 to 2 μm, the insertion of the fibers 05 and 06 and the fitting pin 01 cannot be performed. This is a major factor in connection loss.
Furthermore, since fiber connections using conventional connectors are connected to symmetrical ones, they can be deformed when they are attached for a long time and the loss of connection can be doubled when the direction of dimensional change is reversed. There is.
[0007]
[Non-patent document 1]
"Points of Optical Fiber Technology 200", supervised by Hiroshi Ishihara, Telecommunications Association, published March 20, 1997, p. 258
[Non-patent document 2]
"Easy Optical Fiber Communication", edited by Kenichi Nishimura and Hidetoshi Shirakawa, Telecommunications Association, published on January 20, 1992, p. 81-82
[0008]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention provides a V-groove pedestal for connecting an optical fiber core, which can coaxially buttress two optical fiber cores whose coating is only partially removed at the tip end, and utilizes this V-groove pedestal. By connecting the optical fiber cores in this manner, the structure is such that when used for a long time, the deformation is in the same direction, the connection loss fluctuates little, and the displacement due to external pressure due to vibration or shock hardly occurs.
[0009]
In addition, the invention can be obtained by using the V-groove pedestal for connecting an optical fiber core of the present invention, by the invention to be filed separately (serial number NTTH147523, the title of "Invention method of fiber core", hereinafter referred to as related invention). If the fiber whose end face is polished is connected, it is possible to connect the fiber by a simple method similar to the metallic processing of the metallic transmission line.
Furthermore, in the development of a fiber with a hole such as a PCF (Photonic Crystal Fiber), if a manipulator capable of directly and precisely aligning the core wire is used, the fiber characteristics can be accurately measured, and a fiber with a higher performance hole will be developed. It is possible to help.
[0010]
Problems to be solved by the present invention are described below.
(1) What is better than conventional connectors?
The connector of the present invention is evaluated comprehensively by judging its superiority as compared with a conventional connector in terms of economy, operability and reliability.
[0011]
(2) Fiber setting is easy and there is no damage due to mistakes.
With special skill and complexity, even if it is economical, it may not be widely used.
In addition, it is necessary that there is no variation or damage of characteristics due to an operation error, and that reworkability is good without damage due to an error.
[0012]
[Means for Solving the Problems]
(1) In order to improve economy, operability, and reliability over the conventional connector, it is necessary to reconsider the image of the connector from the ground up and break away from the extension of the existing technology.
However, it is important that conventional techniques can be applied.
[0013]
The present invention is a V-groove pedestal engraved with large and small V-grooves whose depth is adjusted by a core wire holding portion and a coating portion holding portion so that the central axis of the optical fiber is common, and a mold is used. All processes, such as plastic ferrule molding, machining, press working, etc., are extremely reduced in man-hours compared to the prior art, and are excellent in economy.
The present invention is excellent in operability because the fiber core can be easily set from the large V groove to the small V groove.
[0014]
In addition, if the sealing operation is performed by a temperature shrinkable tube method, the fiber is placed in a tube before bonding the fiber, the entire connector is covered, and then heat is applied by a drier to shrink and seal.
A commercially available inexpensive material can be used for the sealing material.
According to the present invention, since the integrated V-groove pedestal has little variation in the fiber installation location, even if it does, the variation in the same direction does not cause a change in characteristics due to connection, and the reliability is high.
Also, since the V-groove pedestal is integrated, there is no deviation from vibration and shock, and a stable state can be maintained.
[0015]
{Circle around (2)} The setting of the fiber in the V-groove is also performed in the conventional connector assembly, and there is no need to acquire new training and skills.
As described above, according to the present invention, conventional equipment and equipment can be used, and newly used items can be entirely covered by commercially available products, so that the burden of new expenses can be minimized.
In addition, since no specialty or training is required, introduction to the site can be easily achieved.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
An optical fiber used for optical communication has its end face polished precisely to minimize connection loss.
When the fiber is polished, cracks occur in the polished end face unless the fiber is completely fixed.
[0017]
Therefore, in the conventional polishing method, the fiber is completely fixed to the ferrule by applying an adhesive also to the end face of the ferrule as shown in FIG.
Therefore, a single fiber cannot be taken out after polishing.
However, as in the related invention, as a fixing means for fixing the fiber to a jig such as a ferrule, the freezing force of a medium that freezes instead of the adhesive, for example, the freezing force of water, is applied, so that the ferrule is polished after polishing. The fiber whose end face has been polished can be removed from the jig.
[0018]
The fiber core wire whose end face is precisely polished can be removed from the jig such as a ferrule after polishing by releasing the freezing, so that the fiber whose end face has been polished can be removed. It is possible to connect an optical fiber whose end face has been polished using a pedestal.
The V-groove pedestal of this integral structure has a structure in which the fiber core with a partially removed coating is set in the large and small V-grooves, so that no fiber set clearance is required at all. Since the fibers can be connected on the same V-groove, the end faces of the fibers can be precisely aligned.
[0019]
Since the end faces of the optical fibers are mirror-polished, the fibers can be connected to each other by a so-called optical contact in which the opposing surfaces of the fibers are brought into close contact with each other as a mirror surface and are connected while maintaining a vacuum state.
On the other hand, in the conventional ferrule, as shown in FIG. 4, the fibers 05, 06 are set on the ferrules 02, 04, adhered, polished, and axially aligned using the fitting pins 01. .
Therefore, if the clearance between the fibers 05 and 06 and the fitting pin hole 03 is not secured about 1 or 2 μm, the insertion of the fibers 05 and 06 or the fitting pin 01 cannot be performed. Can not.
[0020]
On the other hand, by using the V-groove pedestal having an integral structure according to the present invention, it is possible to reduce the connection loss as compared with the related art.
Further, in the case of a multi-core connector, the fibers are set in the V-grooves for each fiber core number. However, since the fibers to be connected are set on the same V-groove, the spacing between the V-grooves is slightly shifted. Also, no increase or fluctuation in connection loss occurs.
Further, as shown in FIG. 3, high reliability is ensured by completely sealing with a sealing material such as a heat-shrinkable tube or a sealing sheet.
[0021]
【Example】
FIG. 1 shows an integrated optical fiber core connecting V-groove pedestal according to an embodiment of the present invention.
As shown in FIG. 1A, the V-groove pedestal 10 has a V-groove 11 for holding two optical fiber cores 5 and 5 to be joined.
As shown in FIG. 1D, the V-groove 11 includes a small V-groove 11a provided at the center of the V-groove pedestal 10 and large V-grooves 11b linearly connected to both sides of the small V-groove 11a. Become.
[0022]
The small V-groove 11a holds the optical fiber core 5 from which the coating 5a has been removed, as shown in FIG. 1B, and the large V-groove 11b has the coating 5a of the coating 5a, as shown in FIG. This holds the applied optical fiber 5.
Further, the small optical fiber core 5 from which the coating 5a held by the small V groove 11a is removed and the small optical fiber core 5 provided with the coating 5a held by the large V groove 11b are concentric with each other. The depths of the V groove 11a and the large V groove 11b are set.
[0023]
FIGS. 2 and 3 show an embodiment of a method of assembling an optical fiber connecting jig using the V-groove pedestal 10 having the above-described structure.
First, as shown in FIG. 2A, the fiber cores 5 are set from both sides in the V-groove 11 of the V-groove pedestal 10 having an integral structure.
That is, the optical fiber cores 5 and 5 whose end faces are polished are inserted into the V-groove 11 from both sides and butt, and the small V-groove 11a holds the optical fiber 5 from which the coating 5a is removed. The optical fiber core 5 coated with the coating 5a is held in the V groove 11b.
[0024]
Next, as shown in FIG. 2B, the optical fibers 5 and 5 whose end faces are polished are fixed to the V-groove 11 of the V-groove pedestal 10 with an adhesive.
Subsequently, as shown in FIGS. 2C and 2D, the holding plate 20 is pressed against the V-groove pedestal 10 with the optical fiber cores 5 and 5 interposed therebetween.
[0025]
Further, as shown in FIGS. 3 (a) and 3 (b), the V-groove pedestal 10 and the holding plate 20 sandwiching the optical fiber cores 5 and 5 are covered with a heat-shrinkable tube (sealing material) 30. As shown in FIGS. 3 (c) and (d), the heat-shrinkable tube 30 is shrunk by heating with hot air using a dryer 40, and is completely sealed and fixed.
In place of the dryer 40, a heater may be used to apply heat to hermetically seal.
Further, instead of the heat shrink tube 30, a sealing sheet may be used for sealing.
[0026]
As described above, the present invention adjusts the depth for holding the optical fiber core and the depth for holding the coating so that the central axis of the optical fiber is common in the connection of the optical fiber core. This is a V-groove pedestal having an integrated structure having two stages of V-grooves, and a method of connecting optical fibers using the V-groove pedestal having the integrated structure.
According to the present invention, an economical connection method of an optical fiber whose end face is polished becomes possible.
In the present invention, the term “connecting jig” is used because the connector is not detachable unlike a conventional connector.
[0027]
【The invention's effect】
As described in detail above, the present invention is a V-groove pedestal in which large and small continuous V-grooves are carved, and the molding of plastic ferrules using a mold, machining, press working, etc. The number of man-hours is extremely small and the economy is excellent.
Also, in the sealing operation, if a temperature shrinkable tube method is adopted, the fiber is passed through the tube before the fiber is bonded, the entire connector is covered, and if heat is applied by a drier or a heater, the tube is contracted and sealed and fixed. Commercially available inexpensive materials can be used for the vacuum device and sealing material for the sealing process.
[0028]
Furthermore, the V-groove pedestal of the present invention can be manufactured only by processing V-grooves having different depths, and is more economical than the conventional technology which requires the production of a highly accurate ferrule such as an optical fiber insertion hole or a fitting pin. Excellent in nature.
Further, according to the present invention, the fiber can be easily set from the large V-groove to the small V-groove, so that the operability is excellent.
[0029]
The V-groove pedestal according to the present invention is excellent in reliability since the fiber installation portion has little variation due to the integral type, and even if it fluctuates, it fluctuates in the same direction, so that the characteristics do not fluctuate due to connection.
In addition, since it is integrated, vibration and shock can be maintained in a stable state without displacement.
In addition, the connection method according to the present invention uses coupling by optical contact without using a refractive index matching agent required in the case of a mechanical splice, so that when connecting a holed fiber such as a PCF using a refractive index matching agent to a hole. It is possible to avoid the problem of a large increase in connection loss due to the intrusion of the matching agent.
[0030]
Furthermore, with the V-groove integrated connector, after setting the positioning fiber in the V-groove, if a positioning jig that has already been demonstrated at the laboratory stage is used, the hole position that affects the optical characteristics can be precisely set. it can.
[Brief description of the drawings]
FIG. 1A is a perspective view showing a state in which an optical fiber core is held, and FIG. 1B is a view showing a V-groove pedestal for connecting an optical fiber according to an embodiment of the present invention. 1 is a sectional view taken along the line BB, FIG. 1C is a sectional view taken along the line AA in FIG. 1, and FIG. 1D is an enlarged perspective view of the V-groove.
FIG. 2 is a process chart showing a method of assembling the optical fiber core connection jig according to one embodiment of the present invention.
FIG. 3 is a process chart showing a method of assembling the optical fiber core connection jig according to one embodiment of the present invention.
4 (a) is a perspective view showing connection of a ferrule by a fitting pin, FIG. 4 (b) is an end view showing a ferrule when an optical fiber is bonded, and FIG. FIG. 4C is a perspective view showing a ferrule at the time of bonding an optical fiber, and FIG. 4D is a perspective view showing fixing by a leaf spring.
FIG. 5A is an end view of a single-core ferrule, and FIG. 5B is an end view of a multi-core ferrule.
[Explanation of symbols]
5 Optical fiber core wire 5a Coating 10 V groove base 11 V groove 11a Small V groove 11b Large V groove 20 Press plate 30 Shrink tube 40 Dryer

Claims (3)

An integrated V-groove pedestal having a V-groove for holding two butted optical fiber core wires, wherein the V-groove is provided with a small V-groove provided at the center of the pedestal and on both sides of the small V-groove. The small V-groove holds the optical fiber core stripped from the coating, the large V-groove holds the coated optical fiber core coated, The depths of the small V-groove and the large V-groove are set such that the optical fiber core held by the small V-groove and the optical fiber core held by the large V-groove are concentric. A V-groove pedestal for connecting an optical fiber core. 2. The method of assembling an optical fiber connecting jig using the optical fiber core connecting V-groove pedestal according to claim 1, wherein the polished end of the optical fiber is inserted into the V-groove and the small V is inserted. An optical fiber, wherein the optical fiber core with the coating removed is held in the groove, and the optical fiber with the coating applied to the large V groove is held, and these are fixed with an adhesive. How to assemble a core connection jig. 3. The method of assembling an optical fiber connecting jig according to claim 2, wherein said V-groove pedestal is pressed down from above by a pressing plate with said optical fiber core wire interposed therebetween, and further, these are covered with a sealing material and completely sealed and fixed. A method for assembling an optical fiber core connection jig.

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