JPH06308352A - Optical fiber ferrule - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object of the present invention to provide an optical fiber array ferrule capable of performing a precise coupling operation between a light emitting / receiving element and an optical fiber array. [Structure] The upper plate 2 has a first accommodating recess 2a formed thinly on the lower rear side thereof, a guide portion 2b formed thickly on the lower front side thereof, a first accommodating recess 2a and a guide portion 2b.
And a first sloped portion 2c formed by the step processing for communicating with each other. The lower plate 3 has a thin second housing recess 3a formed on the upper rear side thereof and an inverted triangular cross-section on the upper front side corresponding to the number of optical fibers V accommodated in the ferrule 1. It has a groove portion 3b and a second inclined surface portion 3c formed by step processing that connects the second storage recessed portion 3a and the guide V groove portion 3b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber array ferrule for aligning an optical fiber used for coupling an optical fiber array to a light emitting element or a light receiving element.

[0002]

2. Description of the Related Art As such an optical fiber array ferrule, the one described in, for example, Japanese Patent Laid-Open No. 4-86802 is conventionally known. This optical fiber array ferrule is composed of two plane plates having an L-shaped cross section, and they are vertically stacked so as to form a space of a predetermined size between the two plates. In this ferrule,
After arranging the optical fiber array in the space between both plates,
While maintaining the clearance between the two plates by a pressure plate using a magnet, at least one of the plates is moved in parallel to the other to narrow the space and position the optical fiber array. That is, in the conventional ferrule, since the optical fibers are aligned by stacking or moving a plurality of parts, precision is required for the assembling work, and the workability is poor.

Further, when an optical fiber array positioned by such a ferrule is joined to an LD array or a PD array, a solder joint is used. With this joint, the outer peripheral portion of the optical fiber array is made into several hundred degrees. It will be heated. As a result, the optical fiber array undergoes thermal stress deformation, which makes it difficult to perform centering coupling fixing on the order of submicrons. In particular, the coupling with the LD array has a problem that the coupling loss cannot be reduced due to the thermal stress deformation.

As an optical fiber positioning structure, a guide pin positioning type multi-fiber optical connector which has already been put into practical use can be cited. However, a ferrule is used to permanently attach an optical fiber array to a light receiving and emitting element. The design concept is different in that it is aimed at precise alignment positioning.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical fiber array ferrule which can solve the above-mentioned technical problems and can accurately perform a coupling work between a light emitting / receiving element and an optical fiber array. Especially.

[0006]

In order to achieve the above object, the invention according to claim 1 is an optical fiber array ferrule in which a plurality of optical fibers are arranged between two plates, wherein the two plates are The gap formed by overlapping is for arranging an optical fiber core wire accommodation part for accommodating the plurality of optical fiber core wires and each optical fiber of the optical fiber core wire accommodated in the optical fiber core wire accommodation part. The optical fiber guide portion having a plurality of grooves and the opening portion continuous with the groove of the optical fiber guide portion.

Here, the invention according to claim 2 is the invention according to claim 1.
In the described optical fiber array ferrule, the two plates may be integrated by laminating and bonding. Further, the invention of claim 3 is the same as claim 2
In the optical fiber array ferrule described, the bonding of the two plates may be anodic bonding. The invention according to claim 4 is the optical fiber array ferrule according to claim 3, in which one of the two plates to be anodically bonded contains aluminosilicate glass. The invention according to claim 5 is
The optical fiber array ferrule according to claim 3,
One of the two plates to be anodically bonded may include an aluminosilicate glass to which an alkali has been added.

Further, in the invention described in claim 6, in the optical fiber array ferrule described in claim 2, the bonding of the two plates may be solid phase diffusion bonding.

Further, the invention according to claim 7 is the invention according to claim 2.
In the described optical fiber array ferrule, the difference in coefficient of thermal expansion between the two plates may be 2 × 10 ⁻⁶ / ° C. under the condition of 300 ° C. or lower.

The invention according to claim 8 may be the optical fiber array ferrule according to claim 1, wherein at least one of the two plates has a window portion.

Further, the invention according to claim 9 is a fixing structure of an optical fiber array, wherein the optical fiber between the window and the opening of the plate of the optical fiber array ferrule according to claim 8 is provided. Each optical fiber is fixed to the groove of the guide part by solder, and the rear part of the optical fiber fixed to the solder and the optical fiber core of the optical fiber are fixed to the optical fiber core receiving part. It is characterized by using an organic adhesive.

[0012]

In the present invention, since the optical fiber guide portion is provided inside the ferrule as an integrated product, each optical fiber of the optical fiber array aligned in each groove of the optical fiber guide portion can be accommodated and the optical fiber can be accommodated. Since the opening of the guide portion is continuous with the groove of the guide portion, it is possible to easily perform the centering coupling and fixing necessary for coupling the end face of each optical fiber exposed from the opening to the LD array or the PD array. it can.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the optical fiber array ferrule of the present invention. (A) is a perspective view showing the overall construction, and (b) is bb 'in (a).
It is a longitudinal cross-sectional view which follows the line, (c) is a side view seen from the optical fiber guide part side, and (d) is a side view seen from the optical fiber core wire storage part side. FIG. 2 is an exploded perspective view showing a state before joining and integrating the optical fiber array ferrule shown in FIG.

In FIGS. 1 and 2, reference numeral 1 is a substantially rectangular optical fiber array ferrule. This ferrule 1
Is composed of an upper plate 2 and a lower plate 3 as shown in FIG. 1 (b) and FIG. Here, for convenience of explanation, the left side of each drawing is the front part of the ferrule 1,
The right side is the rear part of ferrule 1. The upper plate 2 is
A first storage recess 2a formed thinly on the lower side of the rear part thereof;
The guide portion 2b formed thickly on the lower side of the front portion and the first step processing for connecting the first storage recess 2a and the guide portion 2b
It has a slope 2c. The lower plate 3 has a thin second housing recess 3a formed on the upper rear side thereof and an inverted triangular cross-section on the upper front side corresponding to the number of optical fibers V accommodated in the ferrule 1. Groove 3b
And a second sloped portion 3c formed by step processing that connects the second storage recess 3a and the guide V groove portion 3b. The first storage recess 2a is formed longer than the second storage recess 3a along the longitudinal direction of the optical fibers arranged in the ferrule 1, and the guide groove 3b is formed in both the first storage recess 2a and the guide 2b. Facing. In the ferrule 1 including the upper plate 2 and the lower plate 3 which are joined and integrated, the first storage recess 2a and the second storage recess 3a constitute the optical fiber core wire storage part A, and the first storage recess 2a. The guide portion 2b and the guide V groove portion 3b constitute an optical fiber guide portion B. This optical fiber guide section B is
A front guide portion B1 having an optical fiber opening 4 having an inverted triangular cross section at the front end, a first storage recess 2a, and a guide groove portion 3.
and a rear guide portion B2 formed between the rear guide portion B2 and the rear portion b.

In order to integrate the upper plate 2 and the lower plate 3 with each other, it is necessary to previously set V on both plates 2 and 3 at predetermined positions.
After forming the above-described grooves and recesses by groove processing or step processing, the two plates 2 and 3 are bonded without an adhesive layer, for example, by solid phase diffusion bonding or anodic bonding. In solid-phase diffusion bonding, both plates can be integrated by making the bonding surfaces of both plates mirror-like and then bringing the bonding surfaces into contact with each other and heating to a predetermined temperature or higher. For example, when both plates are made of Si, the heating temperature at the time of joining is 1000 ° C. or higher. Anodic bonding is suitable when one plate is made of aluminosilicate glass and the other plate is made of Si. In this case, apply a voltage between both plates and
Integration can be realized by heating at a temperature of 00 to 400 ° C. Further, in the case of this anodic bonding, bonding can be facilitated by adding a predetermined amount of alkali to the aluminosilicate glass. When glass is bonded to one Si plate by sputtering, the applied voltage can be 100 V or less. It is desirable that both plates 2 and 3 are made of the same material from the viewpoint of bonding strength, but if the difference in the coefficient of thermal expansion is 2 × 10 ⁻⁶ / ° C. under the condition of 300 ° C. or less, different materials are used. You may comprise from. With such a difference in the coefficient of thermal expansion, the ferrule 1 itself does not undergo thermal stress deformation due to thermal shock when soldering the optical fiber core wire (260 ° C. × 10 seconds). Therefore, according to the ferrule 1, the optical fiber arranged in the guide groove portion 3b of the optical fiber guide portion B can be easily and accurately centered and fixed to the LD array or the like.

Further, in the above-described embodiment, each opening 4 has an independent structure as shown in FIG.
The adjacent openings 4 may have a continuous shape as shown in FIG.

Further, as shown in FIG. 4, the upper plate 2
The window 5 may be provided in a part of the above. This window 5
The optical fiber guide portion B is formed at a position where the vicinity of the rear guide portion B1 is opened. As shown in FIG. 4B, after inserting the optical fiber core wire 6 into the ferrule 1 and inserting the optical fiber 6a with its coating removed into the optical fiber guide portion B, the opening 4 at the front end of the ferrule 1 is inserted. To solder 7
To fill the inside of the optical fiber guide portion B sequentially in the direction of the arrow. At this time, the solder 7 reaching the window 5 overflows from the window 5 and cannot reach the coating portion of the optical fiber core wire 6, so that the usage amount can be controlled. Also, window 5
Can also be used to release the gas generated inside the ferrule 1. Then, an organic adhesive 8 is injected to the rear of the solder 7 in which the optical fiber 6a is fixed to the optical fiber guide portion B, and the coated portion of the optical fiber core wire 6 is fixed to the optical fiber core wire storage portion A. Such fixing is particularly effective for an optical fiber ferrule for hermetic seal.

In the above embodiment, the upper plate 2 is provided with the window 5 at one place, but as shown in FIG. 5, a plurality of (two in the illustrated example) windows 5 are provided in the front-back direction of the ferrule 1. It may be configured. In this case, there is an effect that the organic adhesive can be easily injected.

In addition to silicon, zirconia, silicon nitride, aluminosilicate glass, or the like can be used as the plate material of the ferrule 1 of this embodiment, but solid-phase diffusion bonding and anodic bonding are also possible. If the material is
Any material can be used. Especially the upper plate 2
When a transparent material such as glass is used as the above, it is possible to observe the inside and to easily insert the optical fiber.

Specific examples will be described below.

(Embodiment 1) A single 4-inch silicon wafer to serve as a lower plate is subjected to continuous V-groove processing by cutting with a depth and pitch processing accuracy of +0.5 μm or less, and a predetermined size. Step processing was performed. On the other one 4-inch silicon wafer, aluminosilicate glass was sputter-deposited to a thickness of about 3 μm. The vapor-deposited film and the bonding surface of the lower plate were anodically bonded to each other to integrate both wafers, that is, both plates. Next, this integrated wafer was cut into a predetermined size and made into chips.
Each chip was a ferrule, and 100 or more chips could be manufactured at one time.

An optical fiber array for 10 fibers was prepared. In this array, single mode optical fibers having an outer diameter of 125 μm are aligned at a pitch of 250 μm. To fix this array in the ferrule, a heat-resistant adhesive that was adhered at 260 ° C. for 10 seconds was used.

By pressing the end portion of the optical fiber of the array against the sloped portion in the ferrule formed by the step processing, the optical fiber is guided to each V groove along the sloped portion, so that it is easy to perform I was able to insert it in the V groove. After polishing the end face of the optical fiber discharged from the opening, the position of each core of 10 cores of the optical fiber array was measured by image processing, and the cores of both sides were set as reference values for all the other 8 cores. It was confirmed that there was an error position within +1 μm. Also, when the obtained optical fiber array ferrules were butted against each other and aligned and soldered, the increase in transmission loss before and after soldering was within 0.5 dB, and sufficient low-loss positioning and fixing can be realized. It was confirmed. The outer surface of the obtained ferrule was plated with Ni-Au to facilitate soldering.

(Example 2) A ferrule was prepared in the same manner as in Example 1 except that the upper plate was made of transparent glass. In this ferrule, the position can be visually confirmed by the transparent upper plate during the optical fiber insertion work, so that the workability can be further improved.

[0026]

As described above, according to the present invention,
Since it is an integrally processed product, distortion due to thermal shock at the time of solder joining to an LD array or the like can be minimized, so that low loss coupling and fixing is possible. Further, the optical fiber guide portion allows easy insertion of the optical fiber into the ferrule. Further, if the upper plate of the ferrule is made of transparent glass, the work of inserting the optical fiber can be further facilitated. Furthermore, if the upper plate is provided with a window, it is possible to easily inject an adhesive or fix the solder of the optical fiber.

[Brief description of drawings]

1A and 1B show an embodiment of an optical fiber array ferrule of the present invention, wherein FIG. 1A is a perspective view showing the entire configuration, and FIG. 1B is a line bb ′ in FIG. FIG. 3 is a longitudinal sectional view taken along the line, (c) is a side view seen from the optical fiber guide portion side, and (d) is a side view seen from the optical fiber core wire accommodation portion side.

FIG. 2 is an exploded perspective view showing a state before joining and integrating the optical fiber array ferrule shown in FIG.

FIG. 3 is a side view of the optical fiber array ferrule according to another embodiment of the present invention as viewed from the optical fiber guide portion side.

4A and 4B show another embodiment of the optical fiber array ferrule of the present invention, wherein FIG. 4A is a perspective view showing the entire structure, and FIG. 4B is a line bb 'in FIG. FIG.

FIG. 5 is a perspective view showing another embodiment of the optical fiber array ferrule of the present invention.

[Explanation of symbols]

 1 Optical Fiber Array Ferrule 2 Upper Plate 3 Lower Plate 4 Opening 5 Window 6 Optical Fiber Core 7 Solder 8 Organic Adhesive A Optical Fiber Core Storage B Optical Fiber Guide

Claims (9)

[Claims] 1. In an optical fiber array ferrule in which a plurality of optical fibers are arranged between two plates, a gap formed by superposing the two plates is an optical fiber containing the plurality of optical fiber core wires. A fiber core wire receiving part, an optical fiber guide part having a plurality of grooves for arranging the optical fibers of the optical fiber core wire housed in the optical fiber core wire receiving part, and the groove of the optical fiber guide part An optical fiber array ferrule, which comprises: 2. The optical fiber array ferrule according to claim 1, wherein the two plates are integrated by laminating and bonding. 3. The optical fiber array ferrule according to claim 2, wherein the bonding bonding of the two plates is anodic bonding. 4. The optical fiber array ferrule according to claim 3, wherein one of the two plates to be anodically bonded contains aluminosilicate glass. 5. The optical fiber array ferrule according to claim 3, wherein one of the two plates to be anodically bonded contains an aluminosilicate glass to which an alkali has been added. 6. The optical fiber array ferrule according to claim 2, wherein the bonding bonding of the two plates is solid phase diffusion bonding. 7. The optical fiber array ferrule according to claim 2, wherein a difference in coefficient of thermal expansion between the two plates is 3 or less.
An optical fiber array ferrule having a temperature of 2 × 10 ⁻⁶ / ° C. under the condition of 00 ° C. 8. The optical fiber array ferrule according to claim 1, wherein at least one of the two plates has a window portion. 9. The optical fiber array ferrule according to claim 8, wherein each optical fiber is fixed to a groove of the optical fiber guide portion between the window portion and the opening portion of the plate by soldering, Further, the fixing of the optical fiber array is characterized in that the rear part of the optical fiber fixed to the solder and the optical fiber core of the optical fiber are fixed to the optical fiber core housing by an organic adhesive. Construction.