WO2003087907A1

WO2003087907A1 - Optical fiber array

Info

Publication number: WO2003087907A1
Application number: PCT/JP2003/004646
Authority: WO
Inventors: Kiyoshi Hayama; Hiroshi Hori
Original assignee: Toto Ltd.
Priority date: 2002-04-12
Filing date: 2003-04-11
Publication date: 2003-10-23
Also published as: AU2003236113A1; JPWO2003087907A1

Abstract

An optical fiber array for arraying / fixing optical fibers, having through holes made in a substrate, spaced with predetermined intervals, and each having an optical fiber positioning portion and a holding portion having a diameter larger than that of the optical fiber positioning portion. An optical fiber array for arraying/fixing optical fibers at predetermined intervals with the axes of the optical fibers positioned parallel to each other, comprising an end substrate having through holes and an end face finished after the optical fibers are passed through the through holes and arrayed, a support substrate supporting the optical fibers, and a spacer for so spacing the end substrate and the support substrate with a predetermined spacing that they are opposed to each other.

Description

Description Optical fiber array Technical field

The present invention relates to an optical fiber array in which optical fibers incorporated in an optical switch, an optical cross-connect, an optical add / drop module, a protection switch, and the like are two-dimensionally arranged with high precision. Background art

In optical communications, a two-dimensional array of fibers has come to be used due to the requirement for wiring a plurality of fibers. Initially, an array was used in which multiple fine holes were opened in the substrate and the fibers were bonded and fixed.

In addition, high-density and high-precision optical wiring requirements (the diameter of the through hole for fixing the optical fiber formed in these optical fiber arrays is 125 to 130 m, and the pitch accuracy is Required), the original method of opening multiple holes in the board did not involve the technology for drilling fine, deep holes with high precision, and was switched to a method of stacking an array with V-grooves on the board. I made it.

Japanese Patent Laid-Open Publication No. Hei 6-2657336 describes an optical fiber array in which optical fibers are two-dimensionally arranged on the end face with high precision using V-grooves. Here, the optical fiber is set two-dimensionally by setting the optical fiber in V-grooves provided on the substrate surface at a predetermined interval, and stacking the units in which the fiber is fixed with the holding plate from above in multiple stages in the vertical direction. Have been proposed.

Also, in a paper (prototype of a high-density two-dimensional fiber array) at the IEICE Spring Conference held in 1993, an optical fiber was passed through a microcapillary and many of these microcapillaries were bundled. A proposal has been made to make an optical fiber array in which optical fibers are arranged two-dimensionally by fixing the periphery with a metal plate or the like. In addition, Japanese Patent Application Laid-Open Publication No. 2000-5006535 discloses that the end of an optical fiber is polished into a cone or a pyramid, and is inserted into a jig whose hole position is precisely machined. A method has been proposed to ensure the positional accuracy of the fiber center.

Further, Japanese Patent Application Laid-Open No. 2002-3656465 discloses that a substrate has a narrow section slightly larger in diameter than the cladding layer of the optical fiber, and a guide for guiding the optical fiber to the narrow section. A wide section with a core shape is formed, the buffer layer at one end of the optical fiber is peeled off to expose a clad layer having a core layer at the center, and this clad layer is inserted into the narrow section, and is inserted into the wide section. There is proposed a method in which an epoxy resin or the like is filled to fix an optical fiber at a predetermined position.

In recent years, there has been a demand for higher speed and higher integration of optical transmission, and in response to this, an optical fiber array has been made multi-channel by arranging 64 or 100 or more optical fibers two-dimensionally. What is done is being demanded.

In addition, from the demand for miniaturization, the hole core pitch is required to be 250 to 1300 m, and the pitch accuracy is required to be 2 x m.

In addition, it is necessary for the light rays emitted from the fiber to accurately reach a lens array or the like at a distance, so that not only the center of the optical fiber but also the parallelism of one axis of the fiber is required.

For such a specification, it is extremely difficult to form a V-groove in a silicon substrate by machining, as disclosed in Japanese Patent Application Laid-Open No. 6-265736. In addition, when the substrates are stacked in the vertical direction, a shift in the horizontal direction due to the stacking occurs. In particular, it is difficult to obtain a high-density configuration with a pitch of 250 / m to 1300 m.

Also, in the method of passing optical fibers through a microcapillary and bundling them, unless the thickness of the microcapillaries is made uniform, the core spacing of the optical fibers will shift. It is extremely difficult to manufacture a micro-capillary with a uniform thickness that does not cause misalignment, and the work of passing an optical fiber through the micro-capillary is troublesome, and the use of an adhesive or the like makes it difficult. Precision positioning is also very difficult.

Furthermore, the material of ceramic products such as micro cavities is made of zirconia. Zirconia also has a problem that dimensional errors occur due to large shrinkage during firing.

In addition, in the method of processing an optical fiber into a conical or pyramid shape and hitting the jig as described in JP-T-2002-506535, there is a high processing cost for the optical fiber, and there is clearance on the back of the jig. It is expected that even if the center position of the tip fiber can be secured, the parallelism of the axes of the optical fiber cannot be secured.

Similar problems _c present invention also say the method disclosed in JP 2002 -365465 can provide excellent optical fibers one array parallelism of the optical fiber one place an optical fiber one high precision axis The purpose is to do. Disclosure of the invention

According to a first aspect of the present invention, there is provided an optical fiber array in which optical fibers are aligned and fixed in a plurality of through holes formed at predetermined intervals in a substrate, wherein the through holes are optical fibers. And a holding part having a larger diameter than the positioning part.

By configuring the through hole into which the optical fiber is inserted with the optical fiber positioning unit that is processed with high precision and the holding unit that supports the optical fiber, the optical fiber can be positioned with high precision. .

The length of the positioning portion in the thickness direction of the substrate is at least 0.3 mm, the diameter of the positioning portion is larger than the diameter of the optical fiber by 0.2 m to 1.4 m, and the holding portion is By increasing the diameter of the optical fiber by 1 / m to 30 with respect to the diameter of the optical fiber, it is possible to process the positioning part, which requires precision, with high precision, and to hold the optical fiber securely.

As the substrate, a silicon single crystal having a thickness of 0.3 mm to 1.5 mm can be selected. In this way, using photolithography technology, a core pitch of 1 m or more can be easily obtained, and large quantities can be processed at once, which is advantageous in terms of cost.

The substrate may be a polycrystalline ceramic having a thickness of 0.3 mm to 1.5 mm. Can be selected. By doing so, the hardness, bending strength, and toughness are high, and there is corrosion resistance, and long-term high reliability can be obtained.

Further, a second invention is an optical fiber array in which a plurality of optical fibers are positioned and fixed at predetermined intervals by positioning the axes of the optical fibers in parallel with each other, and the optical fiber array has an end face that is finished. An end substrate for supporting the end of the optical fiber, a support substrate for supporting a portion distant from the end of the optical fiber, and facing the end substrate and the support substrate at a predetermined interval. It was made up of a spacer. In this way, by arranging the end substrate and the support substrate with a fixed distance by the spacer, the arrangement of the optical fibers and the parallelism of the optical fibers can be highly accurate. In the second invention, the clearance between the through-hole formed in the end substrate and the optical fiber is set to 0.2 to 1.4 m, and the clearance between the through-hole formed in the support substrate and the optical fiber is set. Is from 0.2 m to S m, preferably from 0.2 m to 2 m.

By adopting such a configuration, the optical fiber can be smoothly inserted when the optical fiber is inserted, the positioning can be accurately performed at the end where precision is required, and the distance is maintained by the spacer so that the optical fiber can be inserted. The parallelism of one axis can be reliably maintained. The material of the spacer preferably has a thermal expansion coefficient similar to that of the substrate.

The end substrate and the supporting substrate are made of polycrystalline ceramic having a thickness of 0.15 mm to l mm, so that hardness, bending strength, toughness, corrosion resistance, and long-term high reliability can be obtained. .

Further, the end substrate and the support substrate are made of a silicon single crystal having a thickness of 0.15 mm to 1 mm, so that the core pitch within ± 1111 can be easily formed using photolithography technology. By drawing a mask at the same hole position and drawing only at the hole position for the end and supporting.Using a pair of substrates with masks manufactured with two types of hole dimensions, the parallelism is extremely improved, and large quantities can be processed at once. It is cheap because it can be done. In this case, the through hole is not limited to a circle, but may be a square hole having a predetermined clearance on the opposite side.

In addition, it is effective to secure the parallelism of the axis of the optical fiber even though the substrate may be manufactured by using the same photolithographic mask with only the diameter changed. Further, it is possible to adopt a configuration in which the soother is closed except for an inflow port of an adhesive for bonding the optical fiber. Since the adhesive is put in the spacer, it is desirable to close the spacer so that the adhesive does not leak.

Further, by inserting the optical fiber into the through hole of the optical fiber array and bonding and fixing the optical fiber to at least the end substrate and the support substrate, the optical fiber is raised. An optical connector accurately positioned is obtained. BRIEF DESCRIPTION OF THE FIGURES

1 (a) and 1 (b) are front views showing an optical fiber array.

FIG. 2 is a sectional view of a through hole according to the present invention.

3 (a) to 3 (d) are diagrams illustrating an example of a method for manufacturing a positioning section and a holding section.

FIG. 4 is a cross-sectional view of an optical fiber array including an end substrate, a spacer, and a support substrate according to the present invention.

FIG. 5 is an enlarged sectional view of a main part of the optical fiber array shown in FIG.

FIG. 6 is a perspective view of a spacer.

FIGS. 7 (a) to (e) are diagrams showing another embodiment of the spacer.

FIG. 8 is a sectional view of an optical fiber array according to another embodiment.

FIG. 9 is a diagram showing a method for assembling an optical fiber array according to the present invention.

FIG. 10 is a diagram in which the end substrate according to the present invention is provided with a peeling. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 10.

FIG. 1 is a front view showing an optical fiber array 1. FIG. In Fig. 1 (a), a total of 32 through holes, 12 of 4 x 8 in Fig. 1 (a), are formed on a substrate 11 of 10 mm in height, 10 mm in width, and 1 mm in thickness, and Fig. 1 (b) In this example, a total of 144 through-holes 12 of 12 × 12 are formed. The number of through holes is not limited to these, and can be set arbitrarily.

FIG. 2 is a sectional view of the through hole 12. High precision fiber position within 1 mm thickness The hole of the fixed part 121 is 00.125mm + 1.4m to 10.2m to 0.3mm depth, and the remaining 0.7mm is the hole of the fiber holding part 122 as φ0.125mm + 30m Processed to ~ 11 zm.

A 0.1 mm radius is applied to the insertion opening of the fiber holder to insert the fiber.

Single mode optical fibers 1 are inserted into the 32 through holes 12 of the substrate 11 of the optical fiber array 1, respectively, and after bonding, the fiber end face and the substrate are polished together.

In this polishing, a maximum of about 0.05 mm is cut. Therefore, the depth of the positioning portion 121 is preferably 0.2 mm to 0.4 mm, and more preferably 0.25 mm to 0.35 mm. If it becomes deeper than 0.4 mm, the hole will bend or the diameter will be out of +0.2 mm to +1.4 m per fiber diameter.

After that, the anti-reflection thin film is coated, and a 32-core optical fiber array is completed.

For this reason, high-precision fiber positioning holes can be formed by drilling a hole in a polycrystalline ceramic by micro-hole electrical discharge machining or laser machining, followed by wire-cut electrical discharge machining, laser machining (YAG / Femtosecond), It can be formed with high precision by one or more processes such as tapered wire wrap. In addition, micro hole drilling by ultrasonic processing or grinding can be considered, but it is necessary to consider the wear of the grinding wheel. The polycrystalline ceramic, A l T i C, Z r B 2, Jirukonia, alumina, silicon carbide, silicon nitride, machinable ceramics, and silicon down impregnated silicon carbide applied.

Fig. 3 (a) to (d) are diagrams illustrating an example of a method of manufacturing the positioning part and the holding part. An Altic (electric discharge machining ceramic) having an electrical resistance of 0.003 Ω · cm is used as a substrate. did.

First, the substrate is fixed to the XY stage (work table) of the electric discharge machine, and the XY stage is moved to a predetermined arrangement position where the maximum diameter is 0.1 ^ as shown in (a). The hole was machined. Electrode diameter · The processing conditions used were those that were suitable for the required diameter. Thereafter, as shown in (b), electrical discharge machining was performed with an electrode of 0.1 Φ to the length of the holding portion to form a 0.14 Φ holding portion as shown in (c).

After that, the substrate is set on a high-precision wire-cut work table, a 0.08-φ wire is passed through each hole, moved in a circular shape, and subjected to electrical discharge machining around the wire, and the positioning unit is positioned. And

In this embodiment, a 10 x 10 x 1 mm board is machined in 4 rows x 8 steps (32 holes) at a pitch of 0.25 x 0.25 mm, with a pitch accuracy of ± 2 m and a positioning unit of 0.12 mm. Accuracy of 5φ ~ 0.1265 ^, holding part 0.14φ ~ 0.15φ was obtained.

In this embodiment, the processing of a single substrate is used.However, if it is desired to obtain a positioning portion having a similar upper and lower shape, the individual EDM substrates are overlapped when setting them in a wire cut, and two sheets are simultaneously cut by one wire. do it.

In addition, silicon single crystal can be processed by masking and etching by photolithography.

Further, the through hole may be processed at the same time as the positioning portion and the holding portion, or may be separately processed.

When the positioning part and the holding part are processed separately, the hole serving as the holding part, that is, the hole 1 m to 30 m, preferably about 10 m to 20 m larger than the diameter of the fiber, is about 0.7 mm deep. By drilling first and then processing the positioning portion by the above-described method, the positioning accuracy and the hole diameter accuracy can be processed with high accuracy.

Also, if the R or C chamfer of 30 m to 300 _im is applied to the hole entrance of the holding part, the insertion and assembling of the fiber becomes easier.

The R and C chamfering on the fiber insertion side can be performed by machining with a diamond blade, brush polishing, or ultrasonic processing using loose abrasive grains.

In this embodiment, the displacement of the core of one of the 32 fibers could be assembled within 2.

In addition, since the diameter of the holding part is 1 to 30 m larger than the diameter of one fiber, an optical fiber array that does not have any problems with fiber falling or adhesive strength is obtained. Holes larger than 3 O wm can cause fiber collapse problems. (Example of array)

Next, a cross-sectional view of an example of the assembled array is shown in FIG.

The array is composed of an end substrate 111 having a thickness of 0.4 mm, a support substrate 111 having a thickness of 0.4 mm, and a space provided between the end substrate 111 and the support substrate 112. 13

The end substrate 1 1 1 and the supporting substrate 1 12 are provided with fiber inlets 1 1 1 a and 1 12 a, and the insertion port 1 1 1 a is a fiber holding section to a depth of 0.2 mm from the top. The diameter of the fiber is Φ 0.125 mm + 30 m to 10 m and the lower part 0.2 mm.The diameter of one positioning part is Φ 0.125 mm + 1.4 ^ m to 10 0.2 m, and the upper end is 0.1 mm. The diameter of the inlet 1 12a is φ0.125mm + 2xm ~ + 0.2m, and the upper end has a radius of about 0.05mm.

As shown in FIG. 6, the spacer 13 has a comb-like shape in which four slits 13a opened in the vertical direction and on one side are formed. The width of the slit 13a is 0.2 to 0.3 mm, which serves as a guide for inserting a fiber, and the spacer 13 covers almost the entire area of the substrate. It has the function of backing up the substrate during post-processing such as polishing the tip of the optical fiber attached to 111.

In particular, when the spacer 13 is formed in a comb shape, the slit 13a is opened on the side surface after the end substrate 111 and the support substrate 112 are assembled. The adhesive can be filled in the slit 13a to fix the optical fiber. Also, make the width of the lower end of the slit 13a smaller than the diameter of the upper end of the insertion port 1 1 1a, and make the diameter of the lower end of the inlet 1 12a smaller than the width of the upper end of the slit 13a. By making the size smaller, when inserting the optical fiber 15 from above, there is no problem such that the tip of the optical fiber 1 hits the step and breaks.

7 (a) to 7 (e) are views showing another embodiment of the spacer 13; the spacer 13 shown in FIG. 7 (a) has an insertion hole having a diameter sufficiently larger than the diameter of the fiber. Is formed. The spacer 13 shown in (b) has a shape in which one side is seated. (C) ~ The spacer 13 shown in (e) has a ring shape, a U-shape, and a 拼 shape in which a portion of a bundle of fibers is removed.

FIG. 8 is a cross-sectional view of another embodiment of the array.

In this alternative embodiment, the front side of the hole of the end board 111 having a thickness of 0.3 mm is φθ.125 mm + 1.4 ^ m to 10 / 0.2 / m, and the inner part of the hole is filled with fiber. It is only necessary to secure a diameter that does not cause any obstacles. A radius of about 0.05 mm is applied to the fiber insertion port to make it easier to insert the fiber.

Similarly, the hole of the support substrate 112 with a thickness of 3:11] 11 is set to (|) 0.125 mm + 2 m to 0.2 m, and the same process is performed on the front and back, and the fiber insertion guide and the fiber at the time of assembly are broken. It is difficult.

When the spacer 13 is 3 mm thick and the positions of the through holes in the end substrate and the support substrate are aligned, the maximum tilt of the shaft into which the fiber 1 is inserted and assembled 0 is the outer diameter of the fiber Φ 0.1245 mm, the support substrate If the through-hole of Φ is 0.127 mm, 0.04 degree can be secured by tan0 = 0.0025 / (0.3 x 2 + 3). Similarly, if the spacer 13 has a thickness of 5 mm, 0.03 degrees can be secured.

FIG. 9 is a drawing explaining an example of the method for assembling an array of the present invention.

Adhesion between the support substrate 112, the spacer 13 and the end substrate 111 uses a low-viscosity adhesive.

First, a spacer 13 is placed on the support substrate 112 and is cured. The end substrate 1 11 is brought into contact with the other surface of the spacer 13. In the drawing, the support substrate 112 is placed on the spacer 13, but either one may be on the top.

After that, insert a steel pin gauge 16 of 125.0 // m into the four corner holes in a two-dimensional arrangement of the 32 through holes of both boards, temporarily align the positions of the through holes of both boards, and in this state Then, a plurality of optical fibers 15 are passed through both substrates, and then the pin gauge is removed. At the actual assembly site, it is assumed that the pin gauges are worn or bent, and this is to prevent the displacement of both boards due to this. In this state, an adhesive flows into the mating surface of the spacer 13 and the end substrate 111, and the adhesive is cured.

After curing, remove the pin gauge. If you remove the pin gauge before curing, the board will not Removal after curing is preferred.

After removing the pin gauge 16, the single mode optical fibers 15 are respectively inserted into the through holes, and the optical fibers 15 are bonded to the rear end substrate 111 and the support substrate 112. The adhesive used at this time was low in viscosity and low in shrinkage (such as XL193 manufactured by Mele Technology Co., Ltd.).

The optical fiber used was a clad resin-reinforced one (such as S-Ty 1 us, manufactured by Showa Denki Denki Co., Ltd.) to prevent damage and breakage by the substrate during assembly.

Thereafter, the end face of the fiber 15 and the end substrate 111 are polished together. At this time, in order to reduce the polishing processing cost, difficulty in obtaining accuracy, and the influence of the reflection of the end substrate 111, the end substrate 111 is cut by grinding, leaving only the surface holding the optical fiber 115. It is preferable to polish after making the towel 17 (see Fig. 6).

In this embodiment, as shown in FIG. 10, the surface surrounded by a line 1 mm away from the outermost side of the optical fiber 15 is removed with a # 320 diamond grindstone on a 70-m-deep step. After processing, it was polished. In this polishing, it is cut to a maximum of 0.05 mm (50 im). Therefore, the thickness of the end substrate 111 is preferably 0.2 mm to 1.05 mm, and more preferably 0.25 mm to 0.4 mm.

After that, an anti-reflection thin film is coated, and a 32-core optical fiber array is completed.

When the end substrate 111 is as thin as 0.2 mm, the strength required for post-processing can be obtained by increasing the thickness of the adhesive 14.

Also, it is desirable that the spacer be closed except for the opening of the adhesive inlet. Adhesive leakage can be prevented.

As a method for drilling holes in the fiber positioning part of the substrate 11 with high precision, in polycrystalline ceramics, a pre-drilled hole is made by micro-hole electric discharge machining or laser machining, and then wire cut electric discharge machining, laser machining (YAG * femto) Second), and high accuracy can be achieved by one or more processes such as tape wrapping.

In addition, micro hole drilling by ultrasonic processing or grinding can be considered. Attrition must be considered. The polycrystalline ceramic, A l T i C, Z r B 2, Jirukonia, alumina, silicon carbide, silicon nitride, machinable ceramics, and divorced impregnated silicon carbide applied.

Here, the through holes of the end substrate 111 and the support substrate 112 may be processed at the same time, or may be processed separately.

However, it is more preferable that both substrates are overlapped and processed at the same time, or processed by photolithography using the same mask. In other words, the relative position of the center of the through hole overlaps with extremely high precision, ensuring the parallelism of the fiber 15 and the clearance of the end substrate 11 to 0.2 to 1.4 m, so that the position of the fiber tip Can be determined with high accuracy, and by increasing the size of the support substrate 112 by several microns, it is possible to actually assemble a large number of fibers.

Also, if the R or C chamfer of 30 m to 100 m is applied to the entrance of the through holes of both substrates 1 1 and 1 1 and the exit of the support substrate fiber, it is easy to actually insert and assemble the fiber. It may be good.

The R and C chamfering of the substrate can be done by machining with a diamond blade, brush polishing, ultrasonic processing using loose abrasives, photolitho etching or coating after drilling the substrate.

In the present embodiment, the displacement of the core of one of the 32 fibers is calculated as the average value of the core displacement of 0.8 mm, the standard deviation of 0.6 m, and the maximum displacement of 2.4 zm at a distance of 250 m between the cores. I was able to assemble. The measurement was performed by injecting visible light into the cores of all the fibers in the completed fiber array, photographing the end face with a high-precision camera, processing the images, and calculating the center coordinates of the core.

In addition, since the position of the end substrate 1 1 1 and the support substrate 1 1 1 2 was separated by a spacer 13 of 3 mm, an array with extremely parallel axes of the fibers 15 could be obtained. . Industrial applicability

As described above, according to the present invention, it is possible to easily insert and bond an optical fiber, and to provide an optical fiber array in which fibers can be arranged two-dimensionally with high precision. Further, it is possible to provide an optical fiber array having excellent parallelism between optical fibers in one axis.

Claims

The scope of the claims

1. In an optical fiber array in which optical fibers are aligned and fixed in a plurality of through holes formed at predetermined intervals in a substrate, the through holes have a positioning portion for the optical fiber and a diameter larger than the positioning portion. An optical fiber array comprising a holding portion.

2. The optical fiber array according to claim 1, wherein a length of the positioning portion in a thickness direction of the substrate is at least 0.3 mm, and a diameter of the positioning portion is smaller than a diameter of the optical fiber. 2 / xm to l.4 m larger, and the diameter of the holding part is larger than the diameter of the optical fiber by 1 ^ m to 30 m.

3. The optical fiber array according to claim 1 or 2, wherein the substrate is a single crystal silicon having a thickness of 0.3 mm to 1.5 mm. One array.

4. The optical fiber array according to claim 1 or 2, wherein the substrate is a polycrystalline ceramic having a thickness of 0.3 mm to 1.5 mm. One array.

5. In an optical fiber array in which a plurality of optical fibers are positioned and fixed at predetermined intervals by positioning the axes of the optical fibers in parallel with each other, this optical fiber array is an optical fiber array whose end face is finished. An end substrate that supports the end, a support substrate that supports a location distant from one end of the optical fiber, and a spacer that faces the end substrate and the support substrate at a predetermined interval. An optical fiber array comprising:

6. The optical fiber array according to claim 5, wherein a clearance between the through hole formed in the end substrate and the optical fiber is from 0.1 lm to 1.4: m, and 6. The optical fiber array according to claim 5, wherein a clearance between the formed through-hole and the optical fiber is from 0.2 m to 2 zm.

7. The optical fiber array according to claim 5 or 6, wherein the thickness of the end substrate and the supporting substrate is 0.15 mm to lmm, and the material is silicon single crystal. An optical fiber array.

8. The optical fiber array according to claim 5 or 6, wherein the thickness of the end substrate and the supporting substrate is 0.15 mm to lmm, and the material is a polycrystalline ceramic. An optical fiber array characterized in that:

9. The optical fiber array according to any one of claims 5 to 8, wherein the soother is closed except for an inflow port of an adhesive for bonding the optical fiber. Characteristic optical fiber array.

10. The optical fiber array according to any one of claims 5 to 9, wherein the optical fiber is bonded to the end substrate and the support substrate with an adhesive. Optical fiber array.