JP3652737B2 - Assembling method of multistage optical fiber alignment body - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a structure of an optical fiber alignment component in which a plurality of optical fibers are arranged and sandwiched and fixed by a holding substrate.
[0002]
[Prior art and its problems]
A structure in which a plurality of optical fibers are aligned and fixed two-dimensionally while maintaining the optical axis in parallel is that a plurality of holes are formed at desired positions on a holding substrate that holds the optical fibers. There is a structure in which the end of an optical fiber is inserted. There have been proposed a method for forming a substrate for holding an optical fiber by utilizing anisotropic etching of silicon, or forming a hole by photoetching photosensitive glass. In the case of this method, the position of the end face of the optical fiber is uniquely determined by the position of the hole formed in the holding substrate. However, the thickness of the holding substrate cannot be increased due to the process restrictions for forming the holes. Therefore, there is a problem that it is difficult to hold and fix a large number of optical fibers in parallel with their optical axis directions aligned.
[0003]
Further, as in the conventional example shown in FIG. 4, the optical fiber 3 is installed in the guide groove 4 by using the substrate 1 in which the optical fiber guide grooves 4 such as V-grooves are provided for every pitch of the optical fiber. There is also a method of laminating. In this method, since the optical fiber is fixed by the guide groove, the parallelism between the fibers in the optical fiber optical axis direction can be ensured with high accuracy. However, according to this method, the accuracy of the thickness of the substrate on which the grooves are formed is insufficient, and there is a problem in that optical fiber alignment errors accumulate in the height direction when optical fibers are stacked.
[0004]
The present invention is intended to solve the above-described problems in the conventional structure, and in particular, an easy and practical means for aligning two-dimensional optical fibers by laminating grooved substrates. An object of the present invention is to provide a structure that can accurately fabricate the alignment of the fiber alignment body in the height direction.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems of the prior art, the present invention provides a cylindrical pipe for inserting an optical fiber, and inserts the optical fiber into an alignment substrate having a guide groove for installing the cylindrical pipe into which the optical fiber is inserted. After the cylindrical pipe was installed, the cylindrical pipe was held and fixed by the bottom surface of the upper alignment substrate. If the distance between the center positions of the optical fiber end faces causes an error in the height direction because the thickness of the alignment substrate deviates from the target value, the outer diameter of the combined cylindrical pipe is adjusted to reduce the error. I tried to do it.
[0006]
[Action]
According to the above means, it is possible to greatly reduce the processing steps of the alignment substrate and the fixed substrate necessary for forming a multi-stage two-dimensional optical fiber alignment body, and it is possible to create a lower cost optical fiber alignment body.
[0007]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1A and 1B show an embodiment of an optical fiber alignment body according to the present invention. FIG. 1A is an overall cross-sectional view, and FIG. 1B is an overall perspective view. In this embodiment, an example of a configuration in which the optical fibers are aligned in four rows and four columns in the horizontal direction and four in the height direction is shown. The optical fiber 3 is inserted into a cylindrical pipe 2 having concentric inner and outer diameters. The length of the cylindrical pipe 2 is preferably equal to or longer than that of the alignment substrate 1 because the assembly work is easier. The material of the cylindrical pipe 2 is metal, ceramics or glass. Select according to the usage environment and creation conditions. In this embodiment, in order to easily fix the optical fiber to the cylindrical pipe 2, a glass cylindrical pipe is used. After the optical fiber 3 is inserted into the pipe, the UV curable adhesive is used as the fixing agent. Used, the adhesive is cured by irradiating ultraviolet rays from the outside of the pipe.
[0008]
As the material of the alignment substrate 1, an ultraviolet light-transmitting ceramic material is used. When a glass material is used as the alignment substrate 1, ultraviolet rays can be transmitted and the same fixing operation can be performed, but the following problems actually occur. That is, when the optical fiber core interval is as small as several hundred μm, the thickness of the alignment substrate needs to be equal in order to determine the fiber core interval in the height direction. However, when the glass V-groove substrate is as thin as several hundred μm, the strength is insufficient, and when the V-groove is machined on the glass substrate, the substrate is likely to break along the V-groove. In addition, cracks are likely to occur due to the load pressure during assembly, and further warping of the substrate will occur, causing errors in pitch accuracy. Ceramics are preferable as a material that can withstand the load pressure applied during assembly in strength, and translucent ceramics are particularly excellent in that adhesive curing using ultraviolet rays can be used.
[0009]
The cylindrical pipe 2 into which the optical fiber is inserted is aligned in the V groove 4 formed on the upper surface 13 of the alignment substrate 1 and is held by the groove slope and the bottom surface 14 of the upper alignment substrate. The cylindrical pipe 2 with an optical fiber held in the alignment substrate 1 was fixed using an ultraviolet curable adhesive. Since the alignment substrate 1 transmits ultraviolet rays, even if the ultraviolet rays are irradiated to the entire alignment body from the outside after the assembly is completed, the adhesive is cured, so that the fixing operation can be easily performed. When a ceramic member such as alumina that does not transmit ultraviolet rays is used as the material of the alignment substrate, the cylindrical pipe may be fixed to the alignment substrate using a thermosetting resin or a fixing material such as solder.
[0010]
FIG. 2 shows an example of adjusting the positional accuracy in the height direction when an optical fiber alignment body is constructed by assembling an alignment body and a cylindrical pipe with an optical fiber in multiple layers according to the present invention. The angle of the V groove is 60 °. When the optical fiber center distance H is configured using an alignment substrate having a substrate thickness T and a cylindrical pipe having an outer diameter D, the third step from the bottom of the four alignment substrates with respect to the target value of the substrate thickness T. When the thickness of the alignment substrate 63 is T-dT, the distance between the centers of the optical fibers 42 and 43 is H-dT, which is smaller than the target value. In addition, the positions of the optical fibers in the upper stage are all shifted to a position below by dT. Therefore, the cylindrical pipe 23 having an outer diameter of D + dT is used as the cylindrical pipe aligned in the V groove of the alignment substrate 63. At this time, the center-to-center distance between the optical fiber centers 42 and 43 is equal to H and the initial design value, and the variation in substrate thickness can be absorbed by adjusting the outer diameter of the cylindrical pipe. At this time, the center-to-center distance between the optical fibers 43 and 44 is H + 1 / 2dT as it is, and the cumulative deviation is halved. When the value of ½ dT is larger than the target position accuracy, improvement can be achieved by using an object whose outer diameter of the cylindrical pipe 24 is smaller than D. In this embodiment, the V-groove has an angle of 60 °. However, the outer diameter of the cylindrical pipe can be changed by changing the substrate diameter error even when the angle is other than 60 ° or when the angle is not V-shaped. It is possible to correct with.
[0011]
FIG. 3 shows another example of adjusting the positional accuracy in the height direction when an optical fiber alignment body is constructed by assembling an alignment body and a cylindrical pipe with an optical fiber in multiple layers according to the present invention. In this case, the difference from the example of FIG. 2 is that a cylindrical pipe 25 having a large inner diameter as well as an outer diameter is prepared, and the optical fiber 33 is eccentrically inserted into the cylindrical pipe 25 and fixed. In this example, errors are not accumulated in the height direction when the outer diameters are different.
[0012]
【The invention's effect】
As described above in detail with reference to the embodiments, according to the present invention, an optical fiber alignment body having sufficient accuracy can be easily manufactured.
[Brief description of the drawings]
FIG. 1A is an overall cross-sectional view showing an embodiment of an optical fiber alignment body according to the present invention, and FIG.
FIG. 2 is a cross-sectional view showing a configuration example of an optical fiber alignment body according to the present invention.
FIG. 3 is a cross-sectional view showing another configuration example of the present invention.
FIG. 4 is a cross-sectional view showing a conventional optical fiber alignment body.
[Explanation of symbols]
1, 61, 62, 63, 64 Optical fiber alignment substrate 1 'Fixed substrate 2, 21, 22, 23, 24, 25 Cylindrical pipe 3, 31, 32, 33, 34 Optical fiber 4 Guide grooves 41, 42, 43, 44 Optical fiber core center

Claims (3)

An optical fiber alignment member for aligning the position of the optical fiber end surface two-dimensionally, the plurality having a cylindrical pipe for inserting the optical fiber, the guide groove for installing a cylindrical pipe in which to insert the optical fiber And a fixed substrate installed to hold and fix the cylindrical pipe installed on the uppermost layer, and the cylindrical pipe into which the optical fiber is inserted is installed in the guide groove of each aligned substrate, and the guide groove slope The position of each optical fiber in the height direction is adjusted by changing the outer diameter of the cylindrical pipe installed on the alignment substrate having the error. A method for assembling a multistage optical fiber alignment body , wherein the accuracy is adjusted. An optical fiber alignment member for causing the position of the optical fiber end surface two-dimensionally aligned, comprises a cylindrical pipe for inserting the optical fiber, the guide groove for installing a cylindrical pipe inserting the optical fiber It is composed of a plurality of alignment substrates and a fixed substrate that is installed to hold and fix the cylindrical pipe installed in the uppermost layer, and the cylindrical pipe into which the optical fiber is inserted is installed in the guide groove of each alignment substrate. It is held by the slope and the bottom surface of the upper alignment substrate, and the thickness error of the alignment substrate is changed from the outer diameter of the cylindrical pipe installed on the alignment substrate having the error, and the inner diameter is changed from the cylindrical pipe installed on the other alignment substrate. Adjusting the position accuracy of each optical fiber in the height direction by adjusting it by increasing the size and decentering the optical fiber and fixing it. Method of assembling a body. The length of the cylindrical pipe for inserting the optical fiber is equal to or longer than the guide groove of the alignment substrate for installing the cylindrical pipe into which the optical fiber is inserted, and the alignment pitch at the center of the optical fiber core 2. The assembly of a multistage optical fiber alignment body according to claim 1, wherein ceramics is used as a material for an alignment substrate having a guide groove for installing a cylindrical pipe into which an optical fiber is inserted. Way .

Images