JPH08262266A - Method for aligning optical waveguide - Google Patents

Abstract

PURPOSE: To provide a method for aligning optical waveguides capable of improving the yield of optical waveguide chips without depending on the external shapes of the optical waveguide chips and the characteristics of waveguides in connection of optical communication parts. CONSTITUTION: Straight waveguides 3a and 3b for alignment are formed on the optical waveguide chip 1. The optical waveguide chip l is inserted into a reference ferrule having an optical waveguide chip insertion port larger than the width of the chip. While the probe light is made incident on the straight waveguides 3a and 3b, the optical waveguide chip 1 is moved relative to the reference ferrule until the optical waveguide chip 1 is temporally fixed to the position where incident light is most emitted. The adjustment quantity of the relative positions between the straight waveguides 3a and 3b and the guide holes of the reference ferrule is measured and is then recorded. The waveguide ferrule optimum for the optical waveguide chip 1 is selected from the waveguide ferrules various in the relative positions from the guide holes in accordance with the measured recording. The optical waveguide chip 1 is inserted into the waveguide ferrule and is then adhered and fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a linear waveguide in an optical waveguide chip when connecting two optical communication components in the process of manufacturing the optical communication component, and uses this linear waveguide to adjust the waveguide. The present invention relates to a method of aligning an optical waveguide to be aligned.

[0002]

2. Description of the Related Art Conventionally, when an optical communication component is connected using an optical waveguide chip, the optical axes are aligned and aligned as follows. FIG. 4 is a perspective view showing a step of connecting a waveguide ferrule by a conventional centering method. This Figure 4
When aligning the entrance port, first, the optical waveguide chip 11 in which the branch waveguide 2 is formed is inserted into the optical waveguide chip insertion port 7b of the waveguide ferrule 6b without being fixed by adhesion. Temporarily fix to.

FIG. 5 is a front view showing a light incident portion of an optical waveguide chip inserted in a waveguide ferrule. The probe light from the optical fiber is incident on the opposite side of the incident port of the waveguide 2 shown in FIG. In this case, the side opposite to the insertion portion of the optical waveguide chip 11 into the waveguide ferrule 6b, that is, the emission port side of the optical waveguide chip 11 is fixed with a clamp, and the waveguide ferrule is placed on the pedestal. Align the pedestal by moving it slightly. As a result, the pedestal is moved to a position where the incident probe light is maximized at the emission port. After aligning in this way, the optical waveguide chip 11 and the waveguide ferrule 6b are bonded and fixed by using an adhesive agent with less shrinkage. After that, in the optical waveguide chip 11 bonded to the waveguide ferrule 6b, the unaligned emission ports are aligned in the same manner as described above, and then the optical waveguide chip 1
1 is bonded and fixed to the waveguide ferrule 6a.

When performing the alignment as described above, either the entrance port side or the exit port side may be aligned first. Further, the optical waveguide chip insertion openings 7a and 7b in the waveguide ferrules 6a and 6b are normally both 0.
It is manufactured with an accuracy of 5 μm. On the other hand, the optical waveguide chip 11
In general, the outer shape is manufactured with an accuracy of 0.5 μm, and the position of the branch waveguide 2 is manufactured with an accuracy of 0.1 μm.

After that, the amount of propagation of the light quantity is measured in the waveguide ferrules 6a and 6b connected through the optical waveguide chip 11, and if the loss is within a predetermined standard, it can be said that the connection portion is completed. If it is outside, discard it.

Then, the rod-shaped guide pin is attached to the guide hole 8a.
And 8b or from the guide hole of the waveguide ferrule 6a to prevent the waveguide ferrules 6a and 6b from shifting in the vertical and horizontal directions.

[0007]

However, if the optical waveguides are aligned as described above in the connection of the optical communication parts, the yield will be deteriorated. That is, since the alignment accuracy depends largely on the accuracy of the external dimensions of the optical waveguide chip, if the accuracy of the external dimensions decreases, the alignment accuracy also decreases accordingly. For this reason, if the alignment accuracy is low, the loss of the amount of light often falls outside the predetermined standard, and the number of optical waveguide chips to be discarded increases. In addition, when the characteristics of the waveguide are varied, especially when the waveguide is branched, the output light depends on the manufacturing accuracy of the branched waveguide. Can not be improved.

Further, when the optical waveguide chip is inserted into the waveguide ferrule, since there is not much space between the optical waveguide chip and the optical waveguide chip insertion port of the waveguide ferrule, almost no alignment is possible, and alignment is performed. Therefore, if the waveguide ferrule is forcibly moved, the optical waveguide chip may be damaged.

The present invention has been made in view of the above problems, and in the connection of optical communication components, the yield of the optical waveguide chip is improved without depending on the outer shape of the optical waveguide chip and the characteristics of the waveguide. It is an object of the present invention to provide a method for aligning an optical waveguide that can be performed.

[0010]

According to the method of aligning an optical waveguide of the present invention, a pair of optical communication components are connected by an optical waveguide chip to guide the waveguide of the optical communication component and the optical waveguide chip. In the method of aligning the waveguides with each other, at least two linear waveguides for alignment are formed in the optical waveguide chip, and the optical waveguide chip has a width in a direction perpendicular to the linear waveguides for alignment. A step of inserting the optical waveguide chip into a reference ferrule having an optical waveguide chip insertion opening larger than the width, and the optical waveguide chip to the reference ferrule while injecting probe light into an entrance port or an exit port of the linear waveguide. On the other hand, a step of aligning the optical axis of the linear waveguide with the optical axis of the waveguide of the optical communication component by moving the linear waveguide in a direction perpendicular to the linear waveguide, and guiding the linear waveguide and the reference ferrule. Characterized by a step of recording after measuring the relative position adjustment amount between.

[0011]

According to the present invention, since at least two linear waveguides are formed on the optical waveguide chip and they are used for alignment, a waveguide as in the case of using a branched waveguide is used. It is possible to prevent the loss of light quantity.

Further, in this alignment, a reference ferrule having an optical waveguide chip insertion opening having a predetermined length larger than the longitudinal lengths of the entrance port surface and the exit port surface of the optical waveguide chip is used. The optical waveguide chip is inserted into the insertion port. Then, while the probe light is incident from the entrance port or the exit port of the linear waveguide, the optical waveguide chip is moved relative to the reference ferrule, and the optical waveguide is positioned at a position where the amount of this light is maximum at the exit port. Temporarily fix the tip. The relative position adjustment amount between the linear waveguide and the guide hole of the reference ferrule at this time is measured and recorded.

Then, based on the measurement record of the relative position adjustment amount between the linear waveguide on the optical waveguide chip and the guide hole of the reference ferrule, the waveguide ferrules having various relative positions from the guide hole are formed. The optimum waveguide ferrule for this optical waveguide chip is selected from the inside, and the optical waveguide chip is inserted into the waveguide ferrule and then fixed by adhesion.

Since the alignment is performed using the linear waveguide formed on the optical waveguide chip as described above, the optical communication components can be easily aligned, and the optical waveguide chip need not be discarded. Therefore, the yield can be extremely improved.

[0015]

Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing an optical waveguide chip used in an alignment method according to an embodiment of the present invention. As shown in FIG. 1, in the optical waveguide chip 1, the branch waveguide 2 and the linear waveguides 3a and 3b are formed at both ends thereof on the substrate 4, and the substrate 4 covers the periphery of each waveguide.
The clad 5 is formed on the top.

FIG. 2 is a front view showing the light incident portion of the optical waveguide chip inserted in the reference ferrule. As shown in FIG. 2, the outer shape of the reference ferrule 6 is the same as that of a normally used waveguide ferrule, but the optical waveguide chip hole 7 into which the optical waveguide chip 1 is inserted is larger than the external dimensions of the optical waveguide chip 1. It is about 30 μm larger. The external dimensions of the optical waveguide chip 1 may be lower than the conventional precision, and is manufactured with a dimensional precision of 20 μm.

A method of aligning the optical waveguide using the reference ferrule 6 and the optical waveguide chip 1 will be described. First, the optical waveguide chip 1 is inserted into the optical waveguide chip hole 7 of the reference ferrule 6 and temporarily fixed without being adhered. In this case, since the gap between the optical waveguide chip 1 and the optical waveguide chip hole 7 is about 30 μm, the optical waveguide chip 1 can be moved as shown by the arrow. Then, while the probe light is incident on the incident ports of the linear optical waveguides 3a and 3b, the optical waveguide chip 1 is relatively moved with respect to the reference ferrule 6, and the optical communication components are emitted from the emission ports of the linear optical waveguides 3a and 3b. The amount of light incident on the waveguide is analyzed. Specifically, the probe light from the optical fiber is incident on the linear waveguides 3a and 3b shown in FIG. In this case, the side opposite to the insertion portion of the optical waveguide chip 1 into the waveguide ferrule 6, that is, the probe light incident side is fixed by a clamp, and the waveguide ferrule is placed on the pedestal. Align with a small amount of movement. At this time, the optical waveguide chip 1 is temporarily fixed at a position where the difference between the amount of incident light and the amount of emitted light is the smallest, that is, the position where most incident light is emitted.

After aligning the optical waveguide chip 1 in this way, as shown in FIG. 2, the linear waveguide 3 for the guide holes 8a or 8b provided at the upper ends of both ends of the reference ferrule 6 is formed.
Measure and record the relative position of a or 3b. Specifically, with the center of the insertion surface of the optical waveguide chip in the reference ferrule 6 shown in FIG. 2 as the origin, the position from the center of the guide hole 8a or 8b to the origin, and the center of the incident surface of the optical waveguide chip 1. To the above-mentioned origin, and the relative position from the guide hole to the center of the incident surface of the optical waveguide chip 1 (hereinafter referred to as “optical waveguide chip relative position”) is recorded. In this case, since the waveguides 2, 3a and 3b formed on the optical waveguide chip 1 are formed with high accuracy, the optical waveguide chip 1
The center of the incident surface of can be used as a reference.

Next, the optimum waveguide ferrule is combined with the optical waveguide chip 1 from various waveguide ferrules having different relative positions from the guide hole of the waveguide ferrule to the straight waveguide. In this case, the position from the center of the guide hole to the origin and the position from the center of the insertion port of the optical waveguide chip to the origin are measured with the center of the insertion surface of the optical waveguide chip in the waveguide ferrule as the origin. Then, the relative position from the guide hole to the center of the insertion opening of the optical waveguide chip in the waveguide ferrule (hereinafter referred to as “insertion opening relative position”) is recorded. Based on these recorded relative positions, a waveguide ferrule whose optical waveguide chip relative position and insertion port relative position are equal is selected, and this waveguide ferrule and the optical waveguide chip are combined. Then, the optical waveguide chip 1 is adhesively fixed to the waveguide ferrule.

As described above, since the straight waveguides 3a and 3b formed in the optical waveguide chip 1 are used for the alignment, the influence of the loss of the light quantity such as the branching waveguide is not received during the alignment. Moreover, since the alignment is performed by the two linear waveguides, the alignment on the horizontal plane can be easily performed. Further, since the straight waveguide is used as the reference point for alignment, the outer dimensions of the optical waveguide chip may be smaller than the optical waveguide chip hole of the reference ferrule, and the outer shape can be freely formed.

Next, a case where optical components are connected by using an optical waveguide chip will be specifically described. FIG. 3 is a perspective view showing a process of connecting optical fibers using an optical waveguide chip. As shown in FIG. 3, after measuring the relative position of the optical waveguide chip 1 using the reference ferrule, the optical waveguide chip 1 is inserted into the optimal waveguide ferrules 16a and 16b. And fix it with adhesive. And the optical fiber array 9a
Ferrules 26a and 26b to which 9 and 9b are connected, respectively
Are respectively connected to the waveguide ferrules 16a and 16b, and the guide pins 10 are inserted into both the guide holes to guide the waveguide ferrules 16a and 16b and the ferrules 26a and 26b.
And are prevented from shifting in the vertical and horizontal directions, and the connection part of the optical component is fixed.

The alignment method according to the present invention can be used not only for connecting with a connector but also for connecting fibers with each other by a fusion splicer. Further, the linear waveguide formed on the optical waveguide chip can also be used as a marker when the optical waveguide chip is subjected to mechanical processing such as polishing.

[0023]

As described above, according to the present invention,
By performing alignment using the linear waveguide formed on the optical waveguide chip, pattern formation can be performed without depending on the outer shape of the optical waveguide chip even in the step of patterning the waveguide on the optical waveguide chip. Therefore, the efficiency of the pattern forming work can be improved.

Further, after aligning one straight waveguide, the straight waveguide can be fixed and the other straight waveguide can be aligned, so that the number of man-hours in the aligning work can be reduced as compared with the conventional case. It is possible to reduce the cost of alignment work.

Further, in the present invention, since it is not necessary to discard the manufactured optical waveguide chip, the yield of the optical waveguide chip can be remarkably improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an optical waveguide chip used in an alignment method according to an embodiment of the present invention.

FIG. 2 is a front view showing a light incident part of an optical waveguide chip inserted in a reference ferrule.

FIG. 3 is a perspective view showing a process of connecting optical fibers using an optical waveguide chip.

FIG. 4 is a perspective view showing a step of connecting a waveguide ferrule by a conventional alignment method.

FIG. 5 is a front view showing a light incident part of an optical waveguide chip inserted in a waveguide ferrule.

[Explanation of symbols]

 1, 11; Optical Waveguide Chip 2: Branch Waveguides 3a, 3b; Straight Waveguide 4; Substrate 5; Clad 6; Reference Ferrule 7; Optical Waveguide Chip Holes 7a, 7b; Optical Waveguide Chip Insertion Ports 8a, 8b; Guide Holes 9a, 9b; optical fiber array 10; guide pins 16a, 16b, 26a, 26b; waveguide ferrule

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takuya Ienaka 1440 Rokuzaki, Sakura City, Chiba Fujikura Co., Ltd. Sakura Factory

Claims (1)

[Claims] 1. A method of connecting a pair of optical communication components with an optical waveguide chip to align the waveguide of the optical communication component with the waveguide of the optical waveguide chip, wherein At least two alignment linear waveguides are formed, and the optical waveguide is provided in a reference ferrule having an optical waveguide chip insertion opening whose width in a direction perpendicular to the alignment linear waveguide is larger than the optical waveguide chip width. A step of inserting a chip, and moving the optical waveguide chip relative to the reference ferrule in a direction perpendicular to the linear waveguide while injecting probe light into the entrance port or the exit port of the linear waveguide. The step of aligning the optical axes of the linear waveguide and the waveguide of the optical communication component, and the step of measuring and recording the relative position adjustment amount between the linear waveguide and the guide hole of the reference ferrule. A method for aligning an optical waveguide, comprising: