JPH06118252A - Formation of cleavage plane of optical fiber - Google Patents

Abstract

PURPOSE:To form a cleavage plane capable of avoiding a contaminant deteriorating the performance of a device by scribing the surface to form a defect with a sapphire edge on the surface of a fiber cleaned by a region tapered into a semi-circular cross sectional shape and applied with tension at the position to be cleaved, and generating a cleavage on the fiber at this position to form a flat end face. CONSTITUTION:The 'scribe and break' cutting principle of fiber is used. The surface of a fiber 1 applied with tension 5 is scribed by a cutting means 4. A sapphire, diamond, or tungsten carbide edge is used for the cutting means 4. The bare fiber portion of the fiber 1 is installed on a curved surface mandrel 2, the mandrel 2 is rotated, and the fiber 1 is polished to the necessary depth over the necessary length. The bare fiber 1 is fixed to the holding/arranging device mandrel 2 while being applied with tension 5, its polished face 11 is brought into contact, a knife edge 4 is put on the fiber 1 to cleave it, and a cleavage plane is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a cleaved surface of an optical fiber.

[0002]

2. Description of the Related Art Optical fiber connection methods are roughly classified into permanent connection (splice), which is not removable, and connector connection, which is removable. Permanent connections are used when there is no need to re-separate once connected and fusion and adhesive connections are currently in practice. With either connection method,
Low connection loss, long-term stability of connection part, low cost, easy connection work and short working time are required, and these are important keys.

The fusion method in which the end faces of the optical fibers to be connected are melted by arc discharge heat to form the connection portion and the connection is achieved with low loss and excellent long-term reliability. Currently, it is the most commonly used connection method. In order to obtain this low loss in a stable manner, the cutting state of the optical fiber end face before fusion should be good,
That is, the condition is that the end face has no smoothness, chipping, or protrusions. Stress cutting is generally used as a method for obtaining such a cut surface.

As a method for obtaining such a cut surface, a method utilizing a cleavage phenomenon is considered. That is, although many fiber cleaving means are available, they are suitable for making ends of fibers of standard diameter for fiber splicing. The cleaving means, after satisfying the requirements and cleaving,
The fiber will have smooth, flat end faces.

Further, the fusion method in which the end faces of the optical fibers to be connected are melted by the arc discharge heat to make a connection, and a reliable connection can be surely made with a low loss for a long period of time, so that the most connection method is presently used. It is used. In order to obtain this low loss in a stable manner, the cutting state of the optical fiber end face before fusion, that is, the smoothness of the end face,
The condition is that there are no chips or protrusions. Stress cutting is generally used as a method for obtaining such a cut surface.

[0006]

Accordingly, the present invention provides a method of making a cleaved surface of an optical fiber in which contaminants that degrade the performance of the device can be avoided by cleaning the taper area. To aim. The present invention also provides a method for facilitating the production of Y-connectors for connecting tapered fibers, including cleaved circular tapers and non-circular tapers for circular tapers and multiple fiber fusion splicers. The purpose is to provide a way that can be created.

[0007]

SUMMARY OF THE INVENTION In order to solve the above technical problems, the present invention provides a method for producing a cleaved surface of an optical fiber for assembling a fiber of an optical fiber device, for which a semicircular cross section of the fiber is provided. "Scribe and rupture" of the fiber at the position where it should be cleaved at a predetermined cleavage position by cleaning a region that has been polished into a shape, a region that has been tapered to a semi-circular cross-section, or a region that has been fused and tapered to a semi-circular cross-section. "By applying the principle of cutting, the surface of the fiber under tension is inscribed by a cutting means using a blade of sapphire, dimond or tungsten carbide to make a defect on the surface of the fiber, and the tension causes There is provided a method for producing the above-mentioned optical fiber cleaved surface, characterized in that the fiber is cleaved at the point of contact to form a flat end face.

Generally, the method of obtaining the desired cut surface is accomplished using any suitable means, and the operation shown in FIGS. 1a and 1b is based on the principle of "scribe and fracture" cutting of the fiber. Is. The tensioned fiber surface is inscribed by a cutting means, which uses, for example, a sapphire, diamond or tungsten carbide blade. The fibers can be tensioned to create imperfections in the surface and to create clean, right angled fiber ends. Adjustable cleaving tools are available to cleave fibers of different diameters. However, a common property of all cleaves is that they are only suitable for single, uniform diameter fibers.

The present invention describes a method of cleaving a deformed fiber or fiber assembly, with diameter or shape as the stage during fiber manufacture. In particular, cleaving a polished fiber, or cleaving a taperized fiber, and cleaving a fused and taperized fiber assembly are described. That is, the cleave must be formed in the polished or tapered region. In these cases, it is inevitable that not only the fiber end face is cleaned, but also the fiber itself is cleaned within a range of several cm from the end face. That property is not met by standard cleaving tools.

Fiber devices that require cleaving are as follows. Non-standard cleavage is required in the manufacture of all Y-connected devices, whether polished or tapered. This non-standard cleaving is also required in tapered beam expanders and modal transformers. These are described in detail below.

The manufacture of a polished Y-connector is described below. The polished Y-connector is a three port device with one input and two outputs. A single input port fiber is made into a fused splice by cleaving the fiber ends with standard cleaving tools. The two output port fibers consisted of a single fiber that was polished to the required amount, which was cleaved in the middle of the polished area. The two sides of the polished fiber are then folded to form two output ports. The flat, polished side of the fiber end is placed in lateral contact with the cleaved end located. The assembly method is shown in FIG. Polished Y-connectors are suitable for both multimode and single mode fibers.

The production of a beam expander and a mode-type transformer which are made into a taper will be described.
Circular single-mode fiber tapers and non-circular shaped (typically prismatic) single-mode fiber tapers are both in-line beam expanders and focusers. Worthful as Further, it is valuable as a mode matcher between the circular fiber and the rectangular semiconductor laser or the integrated optical waveguide. To be useful in the above application, the taper section
It must be cleaved in the waste area without contaminating the outer surface of the taper waste.

Creating a taper Y connector (single mode) will be described. The tapered Y-connector is composed of a taper portion in a circular fiber cleaved in the waste area, and a connector (which can have multiple input or output ports) fused in a circle cleaved in the waste area. Both, that is, both the taper portion and the connector are spliced. The single taper section forms the input section where the multi-port half-connector forms the output port. In the waste area of the fused and / or tapered multi-connector, and in the single taper section,
The method of making the cleavage is necessary for the manufacture of this device.

The method for producing a cleaved surface of an optical fiber according to the present invention is a method for producing a cleaved surface in a fiber and a fiber assembly which are deformed as required by the above components. If the fiber is to be polished, or to be tapered, or if it is to be fused and tapered along with the multiplexing of other fibers, it is common to place the fiber between two transfer conversion stages. Tensioned and retained. That is, polished or taper,
Alternatively, the method of making a cleaved surface of an optical fiber of the present invention by making a fused and tapered fiber, tensions the fiber on a transfer conversion step, and is shown in FIGS. Thus, the cleaving blade is provided at a necessary position on the tensioned fiber.

Cleaving a polished fiber or cleaving a tapered fiber in a method of making a cleaved surface of an optical fiber for fiber assembly of a non-standard or geometrical optical fiber or optical fiber device. In cleaving a tapered and tapered fiber assembly, a cleaved surface is formed in the polished or tapered area, and the fiber itself is not only cleaned, but the fiber itself. It is also necessary that the range from 1 to a few cm be cleaned, a property of which is a method of making an optical fiber cleaved surface that is not met by standard cleaving tools.

Next, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[0017]

Example 1 An example in which the cleavage surface forming method of the present invention is applied to a polishing fiber will be described. FIG. 1 is an explanatory diagram for explaining a method for creating a cleavage plane according to the present invention. The present invention is a technique for assembling a fused fiber into a fused abrasive coupler and comprises three stages. First, as shown in FIG. 1a, the fiber 1 is placed on the curved mandrel 2 with the bare fiber portion thereof, the mandrel 2 is rotated, and over the required length (typically, on the order of cm), Polished to the required depth (typically a few microns from the fiber core). Next, as shown in the drawing, the bare fiber 1 to be cleaved is fixed in the holding and arranging device 2 and the like while applying tension 5, and the polishing surface 11 thereof is brought into contact with the knife edge 4 and cleaved. Then, a cleavage plane is prepared. Alternatively, as shown in FIG. 1b, the coated fiber 3 can be cleaved by applying a tension 5 while applying a knife edge 4 to create a cleaved surface. Moreover, as shown in FIG. 1C, the polishing is performed by the fiber clamp 22 in the transfer stage.
By applying tension 25 from both sides, the bare fiber 1 can be hung on the polishing wheel 21 and polished by driving a motor.

Second, when the fiber 1 is placed in a long heating source (typically 1 cm long) and the cleaved fiber portion is placed in a flame and fixed to create a cleaved surface, The residual stress generated during the previous polishing is removed. Thirdly, the cleaved fiber 1 is treated by a suitable heating source, such as an electric arc, flame or laser, as shown in FIG. Cleaved surface (that is, having all the fibers) 12 cleaved by a normal cleaving tool on one of the two semi-circular fibers having a polished surface 15) 1
Butt 3 to melt each other, and melt coupler 1
Make one During such manufacturing processes, the optical properties of such couplers are monitored and melting is continued until the desired properties are obtained.

The features of the fiber arrangement and fixing method are as follows. That is, the biggest problem in manufacturing melt couplers is to hold and position the bare abrasive fiber 1 with the required micron tolerance. After polishing, the two-component fibers 15 and 14 of the coupler must be fixed in the correct arrangement and intimately so that they can be melted. For fibers polished on a support block as described above, this is a relatively simple matter. Large blocks are easy to clamp and can therefore be micromachined in the correct position to give the required coupling.

[0020]

[Embodiment 2] A method for producing a cleavage plane according to the present invention will be described for producing a coupler of a taper type and a coupler of a molten taper type. Both the tapers and the fused and tapered couplers are made by placing the fibers between two transfer conversion stages. Both fibers are fused and tapered by introducing a heating source between the two transfer stages and by separating the transfer stages. The amount of separate transfer steps depends on the degree of taperization required for the fiber device in question. After tapering the fiber, it is necessary to cleave the fiber in the tapered region. The cleaving blade is provided on the taper device at a required position.

Cleavage is performed in the manner shown in FIG. 1b with tension applied between the two transfer conversion stages. That is, the coated fiber 1 is made bare, both ends are pulled, and tension 5 is applied to the bare fiber portion 1 from above, as shown in FIG. 1b. When 4 is applied, the optical fiber 1 is cleaved at the applied point to have a flat end face. As shown in the perspective view of FIG. 2, a Y-joiner is formed by abutting (colliding) and joining (colliding) a Y-type joining fiber 15 which is joined to a fiber 14 having a normal cleavage surface 13 with a polishing taper. Created in. FIG. 3 shows a method of polishing the fiber 1. That is, the fiber 1 coated with the coating 3 is applied with tension 25 from both sides by the fiber clamps 22 at the converting stage and is polished by the polishing wheel 21.

In the method for producing the cleaved surface of the optical fiber according to the present invention, the contaminants deteriorate the performance of the apparatus, so that it is unavoidable that the taper area should be cleaned. A beam expander for taperized Y-connectors, circular tapers and cleaved semi-circular tapers or non-circular tapers for multiple fiber fusion splicers according to the method of making cleaved surfaces of optical fibers of the present invention. I was able to create it. That is, a single fiber is spliced for a single mode, over half that, and for a multimode fiber,
Using the same polishing technique, up to its core, over approximately half, so as to obtain an abrasive fiber of semicircular cross section.
Next, the polished region is cleaved at its center. It is important that the cleaved and polished fiber end face be perfectly flat and at right angles to the fiber axis. As a cleaver, apart from standard diameter circular fibers, new techniques must be developed to obtain sufficient cleavage for polished or semi-circular fibers. This technique requires that the polished fiber be placed in tension. This must be accomplished automatically on the polishing equipment which originally requires tension in the fiber. The polished area is scribed with a cleaving blade in the required position. Engraving on the fiber creates a flat right-angled cleavage in the middle.

[0023]

As described above, the following remarkable technical effects are obtained by the method for forming the cleaved surface of the optical fiber according to the present invention. First, it provided a method of making a cleaved surface of an optical fiber in which contaminants that degrade the performance of the device could be avoided by cleaning the taper area. Second, Y to connect the taperized fibers
A method was provided that facilitates the creation of splices and was able to create cleaved circular and non-circular tapers for circular tapers and multiple fiber fusion splicers.

[Brief description of drawings]

FIG. 1 is a side view showing a state in which a cleavage plane is exposed while applying tension to an optical fiber.

FIG. 2 is a perspective view showing a polished Y-joiner manufactured by abutting and joining all fibers to two half fibers.

FIG. 3 is a perspective view showing how a cleavage plane is created while polishing a fiber.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Curved mandrel 3 Coated fiber 4 Knife edge 5 Tension 11 Butt joint 12 Cleaved surface produced by the method of the present invention 14 All fibers 15 Bonded polished fiber

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kalam Kreyan Ireland, Limerick, Prassey Technical Park, University of Limerick, Lightwave Technology Research Center (72) Inventor Conres Hasse, Ireland, Limerick, Prassay Technology Cal Park, University of Limerick, Lightwave Technology Research Center

Claims (1)

[Claims] 1. A method for producing a cleaved surface of an optical fiber for assembling a fiber of an optical fiber device, for which purpose a region of the fiber polished into a semicircular cross section, a region of a semicircular cross section tapered or fused The sapphire surface is cleaned by applying the principle of "scribe and break" cutting of the fiber to a predetermined cleaving position by cleaning the taperized area in a semicircular cross section. Using a cutting means using a blade of diamond, tungsten carbide, or diamond, it is possible to create a defect on the surface of the fiber by engraving, and the tension causes the fiber to be cleaved to create a flat end face. The method for producing a cleaved surface of an optical fiber as described above.