JP3374508B2 - Optical fiber array - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-core optical fiber array used for parallel optical communication, a branching optical device for optical communication, and the like, and an optical device using the optical fiber array. In the present specification, according to the general definition, a core and a clad are referred to as a bare wire, the bare primary wire is referred to as an element, and the secondary cover is referred to as a core. I will call it (see FIG. 2). 2. Description of the Related Art As shown in FIG. 11 , a conventional multi-core optical fiber array of a core type has a primary coating and a secondary coating for arranging bare optical fiber portions at a desired pitch. At the same time, the bare optical fiber portion is first arranged on, for example, a V-shaped grooved substrate, and the subsequent bare wire portion is curved. (For example, Japanese Utility Model Laid-Open No. 63-4
No. 1105). In the above-described optical device comprising an optical fiber array, an optical waveguide and a case, apart from the curved portion of the optical fiber array, a portion filled with a sealant for fixing the optical fiber and improving the reliability. (Fig. 1
2 ). In the conventional optical fiber array, the ends of the bare optical fibers are arranged at the same pitch as the V-shaped grooves provided on the substrate, whereas the ends of the bare optical fibers are arranged at the same pitch. Can be arranged only at the same pitch as the coating diameter (or at a pitch close to the value obtained by dividing the coating diameter by the number of steps when the optical fibers are stacked in a plurality of stages). For this reason, the pitch of the V-shaped groove provided on the substrate and the coating diameter of the optical fiber (or a pitch close to the value obtained by dividing the coating diameter by the number of steps when optical fibers are stacked in multiple stages) are almost always different. It is. In order to manufacture such a multi-core optical fiber array, a certain distance is provided between the coating portion of the optical fiber and the portion to which the strand is fixed, and the coating portion has a diameter equal to the diameter of the coating portion. (Or a pitch substantially equal to the value obtained by dividing the coating diameter by the number of steps when the optical fibers are stacked in a plurality of steps), and then the V-shaped groove formed at the desired pitch by the bare wire portion In order to arrange the bare wires, the bare wire portions must be arranged in a curved manner at the interval portions. [0006] At this time, there are two drawbacks: the bending portion becomes longer and the optical fiber array becomes larger with the increase in the number of cores, and much time is required for the operation of bending the bare wire portion and arranging it in a V-shaped groove. was there. As a specific example of the former defect, for example, in the case of a 4-core single mode optical fiber array, the core portion of the optical fiber is 0.9 m, which is the same as the diameter of the secondary coating.
m pitch, the bare wire tip is 0.25 mm pitch,
If they are arranged in a horizontal line, the length of the curved portion needs to be at least 13 mm because the allowable radius of curvature of the fiber is R = 40 mm. In the above-described optical device comprising the optical fiber array, the optical waveguide, and the case, apart from the curved portion of the optical fiber array, a portion filled with a sealant for fixing the optical fiber and improving the reliability. Has to be provided, and there is a drawback that the entire optical device becomes larger. Accordingly, the present invention has solved the problem that, in the above-described optical device including the optical fiber array, the optical fiber array, the optical waveguide, and the case, the curved portion becomes longer and the optical fiber array becomes larger as the number of cores increases. , An optical fiber array and an optical device. In order to solve the above-mentioned problems, the present invention provides a method for manufacturing a semiconductor device comprising a plurality of optical fibers and a substrate having a fiber alignment groove for fixing the fibers in parallel. In the optical fiber array, the fiber is a fiber consisting of a bare wire, a bare wire whose primary wire is coated with a resin, and a core wire whose secondary wire is secondarily coated with a resin, and the fiber end is a bare wire portion; It consists of a wire part and a core part,
The substrate has a bare wire portion alignment groove having a pitch of a groove approximately equal to the diameter of the wire and a wire portion fixing portion, the bare wire portion of the fiber is arranged in the groove portion, and the wire portion is the wire portion. The fiber is fixed to the fixing portion at an interval substantially equal to the pitch of the groove, and the core portion of the fiber is further arranged or fastened to the core portion arrangement portion by fastening means, and the strand fixing portion and the core wire arrangement portion or There is provided an optical fiber array in which a strand portion of the fiber is curved in a direction in which the fibers are arranged between the core portion and a fastening portion. Further, in the above-described optical device including the optical fiber array, the optical waveguide, and the case, the optical fiber is bent at a portion where the sealing agent is filled. According to the present invention, the diameter of the strand of the optical fiber is substantially equal to the pitch of the groove for aligning the bare fiber portion. The arrangement can be made at substantially the same pitch as the V-shaped groove pitch. (Embodiment 1) First, a four-core optical fiber array will be described. The optical fiber used is a core type AT &
T mode single mode fiber 11 (trade name: SMF)
The primary coating is made of an ultraviolet-curable acrylate resin having a diameter of 250 ± 15 μm, and the secondary coating is made of PVC having a diameter of about 0.9 mm. The ratio of the cladding diameter to the primary coating diameter in this fiber is about 1: 2. The optical fiber is cut into a required length,
Stripper (VESSEL) at about 25mm from the tip
(Model A: 3000A), only the secondary coating is peeled off. Next, hot stripper etc. (Fujikura Co., Ltd.
Model number: HJS-01) about 10m from the end of optical fiber
The primary coating on the portion beyond the position m is peeled off, and the resin remaining on the side of the bare optical fiber is completely removed with a cloth or the like impregnated with ethanol (see FIG. 2). Similarly, the four optical fibers are cut to remove the coating. The four optical fibers prepared by the above-described method are combined with the wire portion 13 from which only the secondary coating is removed, for example, at a position approximately 20 mm from the tip of the optical fiber and a depth of 250 mm.
Jigs (41, 42) each having a groove having a width of 1 μm and a width of 1 mm (= 250 μm × 4) are arranged in a line so that the positions where only the secondary coating is peeled off are temporarily fixed (FIG. 3). By doing so, the bare wires 12 of the optical fiber are arranged at a pitch of approximately 250 μm. Although a jig is used here, the same result can be obtained by arranging the wire portions 13 from which only the secondary coating is peeled off in a line on a plane and fixing them with an adhesive tape or the like. it can. Next, as shown in FIG. 4, a substrate 21 having a V-groove for aligning bare wires at a pitch of 250 μm is prepared, and the bare wires 12 of the optical fibers arranged by the jigs (41, 42) are removed. The cover 2 is arranged on the V-shaped groove portion 22, and
Cover with 5 and clamp. The bare fiber 12 of the optical fiber protruding from the substrate 21 is cracked with a sharp blade to break it, and a filler 31 such as an epoxy adhesive (Epoxy Technology (USA)
EPO-TEK (registered trademark) 353ND) or glass solder (Cerasolzer W (trade name, manufactured by Asahi Glass Co., Ltd.)) is filled in the gap of the V-shaped groove, and the cover 25 and the bare wire portion 1 are filled.
2 and the substrate 21 are adhesively cured. Although this cover has such a dimension and shape as to cover the bare wire portion of the optical fiber, it may have a structure that covers only a portion corresponding to the bare wire portion of the optical fiber (see FIG. 5). As described above, when the bare wire portion of the optical fiber is cut off, the bare wire end face often has poor planar accuracy with respect to the substrate end face. For this reason, in order to obtain planar accuracy as a fiber array, it is preferable to perform polishing. On the other hand, in a state where the fiber is adhered and fixed to the substrate having the V-shaped groove, the substrate can be cut precisely with a diamond saw or the like to obtain planar accuracy. The material of the substrate having the V-shaped groove is desirably a material in which the V-shaped groove can be easily formed by a method such as machining or etching and whose thermal expansion coefficient is close to that of the optical fiber. . Further, as described above, when polishing is performed to obtain the flatness of the end face of the fiber array, a material having the same surface hardness as that of the optical fiber is preferable. Specifically, glass, ceramic, quartz and the like can be mentioned. Further, the material of the cover is the same as that of the V-shaped grooved substrate. Further, when the optical fiber and the substrate with the V-shaped groove are bonded and fixed, when using a photo-curable resin such as a UV-curable resin as described later, at least one of the substrate with the V-shaped groove and the cover. One of them desirably has a light-transmitting property. The strand portion 13 of the optical fiber on the substrate is bonded and cured with a filler 31, for example, a UV-curing adhesive, to form a strand fixing portion 23. In this example, the strand portion on the substrate is bonded and fixed to form the strand fixing portion. However, it goes without saying that the substrate may have a strand alignment groove. Next, the jig to which the strand was temporarily fixed was removed, and the core of the optical fiber was arranged and fixed in the arrangement section 27 (FIG. 6). The strands are curved between the arrangement part 27. An optical fiber array as shown in FIG. 1 can be manufactured. Also,
The core wire arrangement portion may be provided together with the substrate. Further, the core portion may be fastened by a fixing band or the like. Although the above description has been made with reference to a four-core optical fiber array, it goes without saying that an optical fiber array having an arbitrary number of cores can be obtained in the same manner. (Embodiment 2 ) In this embodiment, a 1 × 4 branch optical device is manufactured using the four-core optical fiber array manufactured in the first embodiment and the one-core optical fiber array. First, a glass 1 prepared by an ion exchange method was used.
The × 4 branch optical waveguide 61 is pigtailed with the four-core optical fiber array 52 and the one-core optical fiber array 51 using, for example, a translucent UV curable resin 33.
Further, the waveguide substrate and the array are bonded and fixed to a base substrate 62 made of a material (for example, glass) having a thermal expansion coefficient close to that of the array using glass solder. See Figure 7. As shown in FIG. 7 , the optical waveguide 61 is connected as if it just bridged the two optical fiber arrays 51 and 52. This is packaged in a case. First, the optical waveguide bonded and fixed to the base substrate and the optical fiber array are put in a small case 91. Further, the small case is put in a large case 92. At this time, between the small case and the large case, the curved portion 1 is formed by the element portion of the pigtail of the four-core optical fiber.
4 is formed, and the portion is solidified with a sealant 32 (ME-352, manufactured by Nippon Pernox Co., Ltd.), and a core case portion 27 of the optical fiber is provided in a large case 92 to produce a 1 × 4 branch optical device. (See FIG. 8 ). The case is made of aluminum or resin. At this time, if the thermal expansion coefficient of the case and the fiber array or the case and the fiber is different,
It is desirable to use a sealant having some elasticity even after curing. It is also effective to use a case made of a material having a thermal expansion coefficient close to that of the fiber array. Examples of such a material include a liquid crystal polyester resin. The dimensional effect of the third embodiment will be described. The current equivalents have a total length of 114 mm and a total width of 1
In contrast to 6 mm, in the optical device of the second embodiment, the overall length can be reduced to 71.5 mm and the overall width can be reduced to 9 mm, and the device can be miniaturized. Although the above description has been given of the case of a 1 × 4 branch optical device, it is impossible to manufacture an m × n branch optical device by using an m-core or n-core optical fiber array according to the purpose. Needless to say. For example, 2 × 1
A six-branch optical device can be manufactured. in this case,
In order to prevent the width of the entire device from becoming large, the strands of the 16-core optical fiber array may be arranged in a two-stage delta arrangement, and the cores may be arranged in a four-stage delta arrangement. Further, in order to prevent the influence of reflection at the connection surface 71 between the optical waveguide and the fiber, it is effective to cut and connect the substrate obliquely. 9 and 10 show examples. As described above, according to the optical fiber array of the present invention, it is not necessary to bend the optical fiber at the bare wire portion, so that the entire length of the optical fiber array can be shortened. In addition, the width of the optical fiber array is sufficient to be slightly larger than the product of the number of cores and the target pitch, as compared with the conventional one (number of cores × covering diameter). Since a portion for bending the bare wire portion is not required, the size of the optical fiber array can be reduced. Further, in an optical device including an optical fiber array, an optical waveguide and a case, by using the optical fiber array according to the present invention, a portion for bending the optical fiber and a portion for sealing the optical fiber can be used. Therefore, the length of the entire case can be shortened, and the entire optical device can be downsized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating an optical fiber array according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating the structure of a core optical fiber. FIG. 3 is a diagram illustrating a state in which optical fibers are arranged in a line at a wire portion and temporarily fixed. FIG. 4 is a diagram illustrating a substrate with a V-shaped groove. FIG. 5 is a diagram showing an example of another cover glass. FIG. 6 is a diagram illustrating an arrangement portion of an optical fiber core portion. 7 is a diagram illustrating a 1 × 4 branching optical device of Example 2. FIG. 8 is a diagram illustrating a case where the 1 × 4 branch optical device is packaged in a case. FIG. 9 is a diagram illustrating a connection portion of an optical device in which an optical fiber array and an optical waveguide are cut obliquely with respect to an optical axis and connected. FIG. 10 is a diagram illustrating a connection portion of another optical device in which the optical fiber array and the optical waveguide are cut obliquely with respect to the optical axis and connected. FIG. 11 is a diagram of an optical fiber array shown in Japanese Utility Model Application Laid-Open No. 63-41105. FIG. 12 is a diagram showing an example of an optical device using a conventional optical fiber array. [Description of Reference Numerals] 11 core optical fiber 12 bare optical fiber portion 13 bare optical fiber portion 14 bent portion of optical fiber 21 substrate with V-shaped groove 22 V-shaped groove for alignment of bare wire portion 23 fixed portion of optical fiber wire 24 Optical fiber strand alignment groove 25 Bare wire part cover 26 Wire part cover 27 Core part arrangement part (core part fastening part) 27a, 27b Core part arrangement part 31 Filler 32 Sealant 33 Translucent UV curable resin 41 Optical fiber temporary fixing jig 42 Temporary fixing jig cover 51 One-core optical fiber array 52 Four-core optical fiber array 60 Optical waveguide 61 1 × 4 branch type optical waveguide 62 Base substrate 71 Connection surface between optical waveguide and optical fiber array 81 Glass solder 91 Small resin case 92 Large resin case

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 6/24 G02B 6/30

Claims (1)

(57) [Claim 1] In an optical fiber array comprising a plurality of optical fibers and a substrate having a fiber alignment groove for fixing the fibers in parallel in parallel, the fibers are:
A bare fiber, a fiber comprising a bare wire in which the bare wire is primarily coated with resin and a core wire in which the bare wire is secondarily coated with resin, wherein the fiber end portion comprises a bare wire portion, a bare wire portion, and a core wire portion; substrate has a bare portion alignment groove and the wire section solid tough having a pitch substantially equal grooves to the diameter of the wire, the bare portion of the fiber is arranged in the groove, the wire section the The fiber is fixed to the fixing portion at an interval substantially equal to the pitch of the groove, and the core portion of the fiber is further arranged or fastened to the core portion arrangement portion by fastening means, and the strand fixing portion and the core wire arrangement portion or An optical fiber array, wherein a strand portion of the fiber is curved in a direction in which the fibers are arranged between the core portion and the fastening portion.