KR20030037285A - Glass cover of optical fiber block for minimizing stress concentration and contacting device therewith - Google Patents

Abstract

PURPOSE: A glass cover for fiber block minimizing stress concentration and a contact device using the same are provided to enhance the reliability by reducing the stress concentration generated from the connection between a PLC(Planar Lightwave Circuit) and a fiber block. CONSTITUTION: A cover(C5) is formed with a glass material or a quartz material or a silicon material. The cover(C5) has a top surface(501) and a bottom surface(502). A plurality of projection portions(504,505) are formed at both ends of the bottom surface(502). The projection portions(504,505) are extended in a straight line. A slot is formed between the projection portions(504,505). The slot is contacted with the bottom surface(502). The projection portions(504,505) are contacted with a bare fiber located on a V-shaped groove of a fiber alignment region.

Description

Glass Cover for Optical Fiber Block Minimizing Stress Concentration and Bonding Apparatus Adopting the Same {GLASS COVER OF OPTICAL FIBER BLOCK FOR MINIMIZING STRESS CONCENTRATION AND CONTACTING DEVICE THEREWITH}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber block connecting a planar waveguide optical circuit (PLC) to an optical fiber. In particular, a glass cover for an optical fiber block minimizing the occurrence of stress applied to an optical fiber and a junction using the same Relates to a device.

In wavelength division multiplexing (WDM) communication systems used to transmit large amounts of information, optical signals having N wavelengths are simultaneously transmitted through a single fiber. In particular, planar waveguide optical circuits (PLCs) are widely used for optical signal processing such as optical signal branching, modulation, switching, signal multiplexing, and the like. In order to connect the planar waveguide optical circuit with the optical fiber, an optical fiber block is used. In addition, such an optical fiber block is one of optical components that are also used as an input / output terminal of a micro-optic device.

1 illustrates a connection state of the planar waveguide optical circuit 10 and the optical fiber blocks 20 and 30 which are generally used. As shown in FIG. 1, each of the input / output side optical fiber blocks 20 and 30 connects the planar waveguide optical circuit 10 to each of the single optical fiber F1 and the ribbon optical fiber F2 and maintains a connection state. Play a supportive role.

N wavelengths are input to the input port of the planar waveguide optical circuit 10 through the single optical fiber F1, and the input optical signal is multiplexed through the planar waveguide optical circuit 10. Each of the multiplexed optical signals is output through the ribbon optical fiber F2, respectively. In this case, the input / output side optical fiber blocks 20 and 30 respectively connected to the input / output ports of the planar waveguide optical circuit 10 are aligned using an adhesive B such as an epoxy resin. In addition, glass covers C1 to C4 are attached to the input / output side and the input / output side optical fiber blocks 20 and 30 of the planar waveguide optical circuit 10, respectively. The glass covers C1 and C2 attached to the input / output side of the planar waveguide optical circuit 10 are for convenience of the process, and the glass covers C3 and C4 adhered to the input / output side optical fiber blocks 20 and 30. Is used to support each of the aligned optical fibers. Reference numeral S denotes a silicon substrate, and an optical circuit is provided on the substrate S so that an optical signal travels.

2 to 4, the configuration of the output side optical fiber block 30 among the conventional optical fiber blocks will be described. Hereinafter, the output side optical fiber block will be referred to as an optical fiber block. As shown in Figs. 2 to 4, the conventional optical fiber block 30 has a fiber alignment area 301 for arranging bare fibers (BF) with peeled coating, and a ribbon optical fiber. The stress relief depth area 302 is provided to reduce the stress generated by the coating thickness. The optical fiber alignment area 301 is provided with a plurality of V-grooves 310 (V-groove) for placing the bare fiber BF. The optical fiber alignment region 301 and the stress reduction depth region 302 are manufactured very precisely by a wet-etching process.

Specifically, the most important function of the optical fiber block 30 is to support the bare optical fiber (BF) placed in the V-groove 310, to fix the arrangement of the bare optical fiber (BF), respectively, the position between the bare optical fibers (BF) It is the most important function that is placed correctly. Therefore, the optical fiber block 30 is important to manufacture the precise V-groove 310, the precise manufacturing of the glass cover (C4) bonded to the optical fiber blister 30. In addition, it is important to fix the alignment of each bare optical fiber (BF) arranged in the V-groove 310, for this purpose, the adhesive (B), for example epoxy resin is added to fix the aligned optical fiber. Of course, the cover C4 is attached to the optical fiber alignment region 301 to support the bare optical fiber BF arranged above.

The optical fiber block 30 and the cover C4 manufactured in this state are diced and polished at a predetermined angle θ through a polishing process, thereby finally completing the optical fiber alignment.

However, as shown in FIG. 3, the bare optical fibers BF are aligned with the respective V-grooves 310, and after the epoxy resin B is introduced, the glass cover C4 is covered and fixed. The following problem occurs. The V-groove 310, the bare optical fiber BF, and the glass cover C4 form contact points at three points P1, P2, and P3, and the three contacts P1, P2, and P3. Is an essential structure for precisely maintaining the arrangement of the bare fiber BF. However, these three contacts P1, P2, and P3 contain considerable stresses due to shrinkage or expansion of the adhesive B injected. The length of the arrow shown in Figure 3 means the stress intensity, the arrow direction means the stress distribution direction. As the stress distribution occurring in the direction of the arrow shown in FIG. 3 is shown, the stress is concentrated at the three contacts, and in particular, the greatest stress occurs at the contacts P3 of the bare fiber and the glass cover. These stresses result in a weakening of the adhesive force of the contact point P3 in the long term, resulting in delamination in which the interfaces forming the contact point fall from each other, thereby degrading optical component reliability. .

Accordingly, it is an object of the present invention to provide a cover for an optical fiber block which minimizes stress concentration and a bonding apparatus employing the same.

Another object of the present invention is to provide a cover for an optical fiber block which minimizes stress concentration between a bare optical fiber and a glass cover, and a bonding apparatus employing the same.

In order to achieve the above object, the present invention provides a cover for supporting an optical fiber placed in at least one V-groove which is bonded to an optical waveguide connecting the optical waveguide element and the optical fiber and arranged in the optical fiber block,

A flat portion having an upper surface and a lower surface;

At least one protrusion extending in a vertical direction of the optical fiber placed in the V-groove and provided at a predetermined position on the bottom surface to support the optical fiber placed in the V-groove facing each other; And

It is composed of slots provided adjacent to and between the protrusions and filled with adhesive.

In addition, the bonding apparatus using a cover according to the present invention, in the bonding apparatus for connecting the optical waveguide type optical circuit and the optical fiber,

An optical fiber block in which at least one optical fiber is arranged in the V-groove; And

Extending in the vertical direction of the arranged optical fibers, having at least one protrusion supporting the arranged optical fiber, and having at least one slot provided between the protrusions and coupled to the optical fiber block by an adhesive. It consists of a cover.

1 is a perspective view showing a state where an input / output optical fiber block is used to bond a conventional planar waveguide optical circuit and each input / output optical fiber, respectively.

2 is a perspective view illustrating a bonding state of an optical fiber block and an optical fiber supported by a cover according to an exemplary embodiment.

FIG. 3 is an enlarged front view of the front view seen from the direction A of FIG. 2; FIG.

4 is a side view seen from the direction B of FIG. 2;

5 is an enlarged perspective view showing a cover for an optical fiber block according to the first embodiment of the present invention;

6 is an enlarged perspective view of a cover for an optical fiber block according to a second embodiment of the present invention;

7 is a perspective view showing an optical fiber supported by a cover and an optical fiber block before polishing revolution according to a first preferred embodiment of the present invention.

8 is a perspective view showing an optical fiber supported by a cover and an optical fiber block after the polishing process according to the first preferred embodiment of the present invention.

FIG. 9 is a front view as seen in direction A of FIG. 8, showing a part of which is enlarged.

FIG. 10 is a side view as seen in the direction B of FIG. 8; FIG.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention. In addition, the same conveying elements have the same reference numerals.

A structure of a cover for an optical fiber block according to a first embodiment of the present invention will be described with reference to FIG. 5. As illustrated in FIG. 5, the cover C5 may be flat, and may be made of glass, quartz, or silicon. The cover C5 has a top surface 501 and a bottom surface 502, and the bottom surface 502 is provided with protrusions 504 and 505 near both ends, in particular the respective protrusions 504. 504 and 505 extend straight. A slot is located between each of the protrusions 504 and 505. Of course, the slot is in contact with the bottom surface, and at least one protrusion 504 and 505 may be provided. 5 shows a cover C5 provided with two protrusions 504, 505.

The protrusions 504 and 505 contact the bare optical fiber placed in the V-groove provided in the optical fiber alignment area to support the upper side. Here, the direction in which the protrusions 504 and 505 extend may be perpendicular to the direction in which the bare fiber is placed when the cover is bonded to the optical fiber block.

6, the structure of the cover for the optical fiber block according to the second embodiment of the present invention will be described. As shown in FIG. 6, the cover C6 is flat and may be made of glass, quartz, or silicon. The cover C6 has an upper surface 601 and a bottom surface 602, and the bottom surface 602 is provided with protrusions 604 to 606 at the centers of both ends and both ends, respectively, between the protrusions. Two slots 607 and 608 are located respectively. Of course, each of the slots 607 and 608 is in contact with the bottom 602 and is adjacent to the protrusions 604, 605 and 606, and at least one protrusion may be provided. Three projections 604, 605, and 606 are provided in FIG. 6. In addition, the protrusions are provided at equal intervals.

The junction structure of the optical fiber block 30 using the cover C5 shown in Fig. 5 will be described with reference to Figs. 7 to 10. As shown in Fig. 7, a planar waveguide type optical circuit and an optical fiber will be described. In order to connect, an optical fiber block 30 is essentially used, and a cover C5 is used to support an optical fiber placed in the V-groove 310 of the optical fiber block. The optical fiber block 30 is provided with an optical fiber alignment region 301 provided with a plurality of V-grooves 310 for placing and aligning a bare optical fiber BF, and a stress etched deeper in the optical fiber alignment region 301. Reduced depth area 302. The optical fiber alignment region 301 is a bare optical fiber (BF) is peeled off the coating of the ribbon optical fiber, the stress reduction depth region 302 is a region where the ribbon optical fiber (F2). The optical fiber bonded in the state shown in Figure 7 is completed through the dicing and polishing process the final optical fiber alignment state. L1 in FIG. 7 refers to a vertical line as a reference, and reference numeral L2 refers to a line for dicing and polishing. In addition, the angle θ means the polishing angle. The optical fiber alignment through the dicing and polishing process is shown in FIGS. 8 to 10.

As shown in Figs. 8 to 10, the cover C5, which is diced and polished at a predetermined angle, is polished and erased from the protrusion located at the tip. The cover C5 is fixed to be spaced apart from the bare optical fiber BF placed in the V-groove 310. That is, a gap exists between the bare optical fiber BF and the bottom surface of the cover C5, and the gap is filled with an epoxy resin B and cured. The protrusion of the cover C5 is in contact with the bare optical fiber BF.

As shown in FIG. 9, when the optical fiber is aligned and fixed using the cover C5 and the optical fiber block 30, the one bare optical fiber BF has two contacts P1 with the V-groove 310. , To form a gap spaced apart from the cover C5 to some extent.

That is, when comparing FIG. 3 and FIG. 9, it demonstrated that the arrow shows the direction of a stress and the length of an arrow shows the intensity of a stress as already mentioned. By employing the cover according to the present invention in the optical fiber junction structure, the strength of the contact point was reduced and the number of contact points was also reduced. However, where the protrusions 504 and 505 are located, the bare optical fiber BF forms three contacts. However, when the cover according to the present invention is applied to the bonded structure, the overall stress distribution is significantly reduced compared to the conventional one. That is, the stress distribution generated between the cover and the bare optical fiber is reduced. The gap between the cover and the bare fiber is about several micrometers. Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but it will be apparent to those skilled in the art that various modifications are possible without departing from the scope of the present invention.

As described above, the present invention can minimize the stress concentration occurring in the connection between the planar waveguide type optical circuit and the optical fiber block, thereby achieving the advantage of improving the reliability of the product.

Claims (10)

A cover for supporting an optical fiber placed in at least one V-groove bonded to an optical waveguide device and an optical fiber block connecting the optical fiber to the optical fiber block, A flat portion having an upper surface and a lower surface; At least one protrusion extending in a vertical direction of the optical fiber placed in the V-groove and provided at a predetermined position on the bottom surface to support the optical fiber placed in the V-groove facing each other; And And a slot provided adjacent to and between the protrusions and filled with an adhesive. A cover for supporting an optical waveguide device and an optical fiber bonded to an optical fiber block connecting optical fibers and placed in at least one V-groove array arranged in the optical fiber block, A flat portion having an upper surface and a lower surface; At least one protrusion extending in a vertical direction of each of the optical fiber arrays placed in the V-groove array, the at least one protrusion being provided at the bottom surface and supporting each of the optical fiber arrays placed in the V-groove array face to face; And And at least one slot disposed adjacent to and between the protrusions. The cover of claim 2, wherein the protrusion is configured to be in contact with the optical fiber when the cover is coupled to the optical fiber block. The cover of claim 2, wherein the protrusion is spaced apart from the optical fiber block to provide a gap when the cover is coupled to the optical fiber block. The glass cover of claim 2, wherein the slot is spaced apart from the optical fiber block to provide a gap when the cover is combined with the optical fiber block. The cover of claim 2, wherein the slot is spaced apart from the optical fiber to provide a gap when the cover is combined with the optical fiber block. The cover of claim 2, wherein the cover is made of glass. The cover of claim 2, wherein the cover is made of silicon. The cover of claim 2, wherein the cover is made of quartz. In the bonding device for connecting the optical waveguide type optical circuit and the optical fiber, An optical fiber block in which at least one optical fiber is arranged in the V-groove; And Extending in the vertical direction of the arranged optical fibers, having at least one protrusion supporting the arranged optical fiber, and having at least one slot provided between the protrusions and coupled to the optical fiber block by an adhesive. Bonding device, characterized in that consisting of a cover.