JP2003344694A - Light guide device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light guide device for simply managing to arrangement of an optical fiber, by simplifying optical axis matching of a core and an optical fiber, hardly having distortion of the optical fiber, and hardly producing deterioration in optical characteristics, in the light guide device connecting the core of a light guide chip and the optical fiber. <P>SOLUTION: The light guide device has a structure for connecting the optical fiber and the core of the light guide chip, and fixing a ferrule with a depressed plate, by polishing the ferrule and the end face of the optical fiber incorporated in the ferrule, and arranging the ferrule in a groove formed on the light guide chip. A diameter of the ferrule is 0.25-1.25 mmϕ, and the groove formed on the light guide chip is a V-shaped groove. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide device having a structure in which a core of an optical waveguide chip and an optical fiber are connected.

[0002]

2. Description of the Related Art In an optical waveguide chip, an optical waveguide core for demultiplexing and multiplexing light is branched into a plurality of parts. In order to connect the optical waveguide chip and an optical fiber to the outside, Conventionally, an optical waveguide device in which an optical fiber array is connected to an optical waveguide chip has been used. That is, the optical fiber array is composed of a substrate having a plurality of V grooves and a pressing substrate for pressing the optical fibers. After the optical fibers are arranged in the V grooves, the optical fibers are sandwiched and fixed by the pressing substrate to perform mirror polishing. Also, after the optical axis of the polished optical waveguide chip and the optical axis are adjusted, the substrate having the V groove and the pressing substrate are integrally fixed by an adhesive or the like.

[0003]

However, when the optical fiber array having the above structure is used, there are the following problems. 1. When the optical fiber is arranged in the V groove of the optical fiber array and fixed by the holding substrate, in addition to the stress due to the adhesive for fixing, the optical fiber has two places from the V groove and three places including the holding substrate. A compressive stress is applied from. Due to this stress, the refractive index of the core of the optical fiber changes, the optical waveform is disturbed, and there is a problem that the optical characteristics deteriorate, such as an increase in optical loss. 2. Aligning the optical fibers to a large number of V-grooves is very troublesome and leads to cost increase. Further, since the clad diameter of the multi-core optical fiber varies, fixing the optical fiber in the V-groove may cause optical connection failure due to uneven fixing position accuracy depending on the optical fiber. In order to take out, there is an Assy problem that it is necessary to select and use those having similar diameters. 3. Compared with the conventional single-core connector adhesive fixing and polishing, which is a completed technology, it is technically difficult to polish multiple optical fibers that are adhesively fixed, and the jigs and tools are also special (dedicated). This leads to an increase in cost, and if even one of the multi-core optical fibers causes poor polishing, it is necessary to redo all of them, which is extremely troublesome. In addition, if the manufactured optical fiber array is damaged or chipped, it is necessary to realign and repeat the process from the beginning. 4. In the case of multiple cores, a special construction method and know-how are required to adjust the optical axes of the optical waveguide chip and the optical fiber array. That is, when the optical axis alignment is performed using the optical waveguide chip and the optical fiber array, a special device is used to temporarily connect the optical waveguide chip and the optical waveguide chip so that the amount of received light is maximized. It is fixed after it is aligned with the optical fiber array. However, even if one optical fiber can be connected so that the amount of transmitted light is maximized, for other optical fibers, variations in the outer diameter of the optical fiber itself in manufacturing and the core spacing on the optical waveguide chip may occur. Because of variations,
It is not always possible to make the amount of transmitted light similar, and therefore it is necessary to connect the optical waveguide chip and the optical fiber array at the position where the total amount of transmitted light of multiple optical fibers is the maximum, which is troublesome. It is difficult to efficiently obtain a connection with excellent optical characteristics.

[0004]

SUMMARY OF THE INVENTION The present invention is an optical waveguide device which solves the above problems, in which an end face of a ferrule and an optical fiber contained in the ferrule is polished to form the ferrule on an optical waveguide chip. The optical fiber and the core of the optical waveguide chip are connected to each other, and the ferrule arranged in the groove of the optical waveguide chip is fixed by a pressing plate. Which leads to improved yield,
An optical waveguide device having various characteristics such as cost reduction is provided.

[0005]

Next, an optical waveguide device of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view showing an optical waveguide device of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, on an optical waveguide chip 1 formed of silicon semiconductor, glass, polymer, or the like. A plurality of cores 2, which are the end circuits of the optical waveguide, are formed in the optical waveguide, and the same number of V-grooves 3 having a desired accuracy are formed corresponding to the cores 2. Further, the optical waveguide chip 1 has a slit portion 4 formed therein. On the other hand, a through hole 5A is formed in the longitudinal direction of the ferrule 5, an optical fiber 6 is fixed in the through hole 5A by adhesion or the like, and both end faces of the ferrule 5 and the optical fiber 6 are polished. The ferrule 5 is arranged in the V groove 3 to connect the optical fiber 6 and the core 2. At this time, the ferrule 5 is pulled out to the outside of the optical waveguide chip 1.

The outer diameter of the ferrule 5 is arbitrary so as to match the positions of the optical fiber 6 and the core 2 according to the dimensions such as the width and depth of the V groove 3 formed corresponding to the interval between the cores 2. Although it is set, if the outer diameter is too thin, there is a problem in strength, and conversely if it is thick, the optical waveguide chip must be thick and wide, which makes it difficult to form the V groove. The range of 0.25 to 1.25 mmφ is particularly preferable.

The material of the ferrule 5 is alumina,
Examples thereof include ceramics such as zirconia, resins, metals, glass and the like, but ceramics, particularly zirconia, are preferable from the viewpoint of strength, toughness, abrasivity and optical fiber protection. Both end surfaces of the ferrule 5 are polished by a method such as flat surface polishing, spherical surface polishing, and oblique polishing. By polishing, the ferrule 5 and the optical fiber 6 are flush with each other. By using the same surface, unlike the case where the optical fiber alone is arranged in the V groove, the tip of the optical fiber does not move and the connection with the core is ensured.

By using the ferrule 5 having the optical fiber 6 built-in, the size and accuracy of the outer diameter of the ferrule 5 can be simply controlled in accordance with the V groove 3 formed in the optical waveguide chip 1. It is possible to make a reliable connection without adjusting the optical axis, and it is possible to easily deal with multiple cores.
Regarding the relationship between the V-groove and the ferrule, the shape of the V-groove on the optical waveguide chip is determined in advance as described above, and the outer diameter of the ferrule is set accordingly, or the outer diameter of the ferrule is determined. In this case, it is possible to design with a degree of freedom that the shape of the V groove may be determined in accordance with this.

FIG. 3 is a sectional view showing a fixing structure of the ferrule 5. The plurality of ferrules 5 arranged in the V groove 3 are fixed by a pressing plate 7, and are fixed by an adhesive (not shown). There is. At this time, ferrule 5 is V
Although the stress is applied from three points by the two points from the groove 3 and the pressing plate 7, it is not deformed due to its high mechanical strength. Therefore, unlike the structure in which the optical fiber itself is directly fixed to the V groove, the optical fiber contained in the ferrule is not deformed or the tip position is not deformed, and stable optical connection characteristics can be obtained.

The optical waveguide device obtained by the above embodiment is connected to the outside through the other end of the ferrule 5 having the optical fiber 6 built therein. As shown in FIG. The other end of the ferrule 5 that has been pulled out to is inserted into one end of the sleeve 8 to be fitted therein, and the end of the second ferrule 9 is inserted into and fitted from the other end of the sleeve 8. The optical fiber 16 is fixed in the second ferrule 9 by adhesion or the like.
And one end of the optical fiber 16 is polished, and the optical fiber 16 is extended on the other end side. The polished end surface of the second ferrule 9 and the end surface of the ferrule 5 are butted against each other in the sleeve 8 and the optical fiber 6 in the ferrule 5 and the second end
The optical fiber 16 in the ferrule 9 is connected. By applying this configuration to all ferrules 5, 2
It is possible to easily connect to the outside even with multi-core such as 0 core and 50 cores. The sleeve has a cross section C
Examples include character-shaped split sleeves and cylindrical precision sleeves.
Ceramics, metals, resins and the like are used as the material, but ceramics and metals such as zirconia are particularly preferable.

FIG. 4 is a cross-sectional view showing another embodiment of the optical waveguide device. An optical fiber 26 is fixed to the through hole 5A of the ferrule 5 by adhesion or the like, and one end of the ferrule 5 and the optical fiber 26 is formed. To polish.
The ferrule 5 is disposed in the V groove 3 formed in the optical waveguide chip 1, and the polished optical fiber 26 on one end side is connected to the core 2 of the optical waveguide chip 1, and the other end side of the ferrule 5 is on the optical fiber 26. The structure will be extended as is. Although not shown, in order to protect the optical fiber 26 extended from the other end of the ferrule 5, an optical fiber cord having the outer circumference coated may be used.

Next, a method of assembling the optical waveguide device of the present invention will be described. First, at the same time as machining, etching or chip manufacturing on the optical waveguide chip 1, the core 2
The V groove 3 corresponding to is produced. Next, considering the width and depth of the V groove 3, the outer diameter of the ferrule 5 is set so as to match the position of the core 2 to be connected, and precision polishing is performed. The optical fiber 6 is inserted into the through hole 5A of the ferrule 5, adhered and fixed, and then both ends are polished. Next, the polished ferrule 5 is placed in all the V-grooves 3 to connect the optical fiber 6 and the core 2, the pressing plate 7 is placed on the ferrule 5, and the ferrule 5 is fixed and fixed with an adhesive or the like. At this time, V
Since the outer diameter of the ferrule 5 is set according to the size of the groove, it is not necessary to adjust the optical axis. In the optical waveguide device obtained by the above method, the other end of the ferrule 5 pulled out to the outside of the optical waveguide chip 1 and the end portion of the second ferrule 9 are fitted into the sleeve 8 so that the light inside the ferrule 5 is The fiber 6 and the optical fiber 16 fixed in the second ferrule 9 by adhesion or the like are connected. In the above assembly, the case of using ferrules with both ends polished was explained, but only the end of the one connected to the core was polished,
The other end may be directly connected to the optical fiber cord.

[0013]

The optical waveguide device of the present invention has various characteristics as follows. 1. Since the optical fiber is protected by the ferrule with high strength, the distortion of the optical fiber due to the stress when fixed in the groove is eliminated, and the optical characteristics are not deteriorated. 2. The conventional alignment of the optical fiber itself is laborious and costly when using multiple cores, but since the alignment can be easily managed by using a ferrule, it is possible to handle multiple cores such as 20 cores and 50 cores without any problems. ,It does not take time and effort. 3. Since the optical axis of the optical fiber and the core can be adjusted only by the outer diameter of the ferrule according to the dimensions and accuracy of the groove, it is inevitable that the ferrule is fixed in the groove. It is very easy because there is no need for a special construction method for adjustment. This is a particularly prominent feature in multicore. In addition to the above-mentioned characteristics, since the conventionally used array is not used, the optical waveguide chip, the ferrule, the sleeve, and the like can be manufactured separately, and can be appropriately combined and manufactured, which is troublesome. In the case of multiple cores, the connection becomes easy, and furthermore, it is possible to instantly connect to the outside by using a split sleeve or the like. The present invention has a remarkable feature particularly in the case of multi-core, but it is needless to say that it can be applied to single-core.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an optical waveguide device of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view showing a ferrule fixing structure.

FIG. 4 is a partial cross-sectional view showing another embodiment of the optical waveguide device of the present invention.

[Explanation of symbols]

1 Optical waveguide chip 2 cores 3 V groove 5 ferrules 6 optical fiber 7 Press plate 8 sleeves 9 second ferrule 16 optical fiber 26 optical fiber

Claims (6)

[Claims] 1. A method of polishing an end face of a ferrule and an optical fiber contained in the ferrule, arranging the ferrule in a groove formed in the optical waveguide chip, and connecting the optical fiber and the core of the optical waveguide chip. Characteristic optical waveguide device. 2. The optical waveguide device according to claim 1, wherein the ferrule arranged in the groove of the optical waveguide chip is fixed by a pressing plate. 3. A ferrule and an optical fiber contained in the ferrule are polished on both end faces, and one end of the optical fiber is connected to a core of the optical waveguide chip by arranging the ferrule in a groove of the optical waveguide chip. By inserting the other end of the ferrule into one end of a cylindrical or C-shaped sleeve for fitting and inserting the end of the second ferrule into the other end of the sleeve for fitting, The optical waveguide device according to claim 1 or 2, wherein the optical fiber and the optical fiber in the second ferrule are connected. 4. The ferrule has an outer diameter of 0.25 to 1.25 m.
The optical waveguide device according to any one of claims 1 to 3, wherein m is φ. 5. The optical waveguide device according to claim 1, wherein the groove formed on the optical waveguide chip is a V groove. 6. The optical waveguide device according to claim 1, wherein the material of the ferrule is zirconia.