JP2016075744A - Optical device and optical device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device that curbs reduction in position accuracy among optical components to be aligned using a pin and a hole into which the pin is inserted.SOLUTION: An optical device 1 includes: a ferrule 10 that has a pair of guide pins 12; and a substrate 20 that opposes the ferrule 10, and has a pair of pinholes 22 each non-similar to the pair of guide pins 12 in a plane view. The pair of guide pins 12 is inserted into the pair of pinholes 22, respectively, and is abutted against a lateral wall on a direction P side of pinholes 22. The pair of guide pins 12 is configured to be biased on the direction P side of the pair of pinholes 22, and the guide pin and the pinhole are used to thereby curb reduction in position accuracy between the ferrule 10 and the substrate 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical device and a method for manufacturing the optical device.

  Techniques for connecting optical components such as connection between a ferrule (fiber block) and an optical module and connection between ferrules are known. Technology for positioning between optical components by providing pins on one of the optical components to be connected, holes on the other, and placing the optical components so that the pins are inserted into the holes. It has been known.

JP 2005-49389 A JP-A-8-94883

  Conventional pins and holes are similar in plan view, for example, a pin having a circular cross section and a hole having a flat circular shape, and the center thereof is one of the position references. However, in that case, the clearance (play) provided between the pins so that the pins can be inserted into the holes, and the tolerance between the pins and the holes (manufacturing tolerance) are decentrations of the pins in various directions with respect to the holes. In some cases, the positional error of the components is caused, and the positional accuracy between the optical components is lowered.

  According to an aspect of the present invention, a first optical component having a first pin and a second pin, and the first optical component facing the first optical component, and the first pin and the second pin are dissimilar in plan view. A second optical component having a first hole and a second hole, wherein the first pin and the second pin are inserted into the first hole and the second hole, respectively. An optical device is provided in contact with the side wall of the two holes in the first direction.

  Further, according to one aspect of the present invention, the first pin and the second pin provided on the first optical component are provided on the second optical component facing the first optical component, respectively, and the first pin is seen in plan view. Inserting the first pin and the second pin into the first hole and the second hole, respectively, and inserting the first pin and the second pin into the first hole and the second hole, respectively. And a method of manufacturing the optical device including a step of contacting the side wall on the first direction side.

  According to the disclosed technique, it is possible to realize an optical device with high positional accuracy between optical components using a pin and a hole into which the pin is inserted.

It is FIG. (1) which shows an example of the optical apparatus which concerns on 1st Embodiment. It is FIG. (2) which shows an example of the optical apparatus which concerns on 1st Embodiment. It is FIG. (1) which shows an example of the assembly method of the optical apparatus which concerns on 1st Embodiment. It is FIG. (2) which shows an example of the assembly method of the optical apparatus which concerns on 1st Embodiment. It is FIG. (1) which shows an example of the assembly method of the optical apparatus which concerns on 2nd Embodiment. It is FIG. (2) which shows an example of the assembly method of the optical apparatus which concerns on 2nd Embodiment. It is FIG. (1) which shows an example of the optical apparatus after the assembly which concerns on 2nd Embodiment. It is FIG. (2) which shows an example of the optical apparatus after the assembly which concerns on 2nd Embodiment. It is FIG. (1) which shows an example of the formation method of the optical waveguide board | substrate which concerns on 2nd Embodiment. It is FIG. (2) which shows an example of the formation method of the optical waveguide board | substrate which concerns on 2nd Embodiment. It is FIG. (3) which shows an example of the formation method of the optical waveguide board | substrate which concerns on 2nd Embodiment. It is explanatory drawing (the 1) of the position error by the tolerance of the guide pin and pin hole which concerns on 2nd Embodiment. It is explanatory drawing (the 2) of the position error by the tolerance of the guide pin and pin hole which concerns on 2nd Embodiment. It is a figure which shows an example of the relationship between angle (theta) and positional offset amount. An example of a planar arrangement of θ = 60 °, 90 °, and 120 ° pin holes and guide pins inserted into the pin holes is shown. It is a figure which shows an example of the optical apparatus which concerns on 3rd Embodiment. It is explanatory drawing (the 1) of the position error by the tolerance of the guide pin and pin hole which concerns on 3rd Embodiment. It is explanatory drawing (the 2) of the position error by the tolerance of the guide pin and pin hole which concerns on 3rd Embodiment. It is explanatory drawing (the 1) of the pressing direction of the guide pin which concerns on 4th Embodiment. It is explanatory drawing (the 2) of the pressing direction of the guide pin which concerns on 4th Embodiment. It is explanatory drawing of the structural example of the pin hole which concerns on 5th Embodiment. It is explanatory drawing of the tolerance of a guide pin and a pin hole. It is explanatory drawing (the 1) of the position error by the tolerance of a guide pin and a pin hole. It is explanatory drawing (the 2) of the position error by the tolerance of a guide pin and a pin hole.

  Optical signals are suitable for high-speed and large-capacity signal transmission, and have already been put into practical use in long-distance backbone communication systems. Information system devices such as computers have already been put to practical use between devices due to high-speed signals, and the introduction of optical signals into devices and boards is now in the field of view. As a wiring member for connecting distant positions, an optical fiber is superior in terms of performance and price. On the other hand, a portion for processing an optical signal, for example, an optical transceiver, an optical coupler, an optical splitter, an AWG (Arrayed Waveguide Grating) or the like is often formed on a substrate such as an optical waveguide substrate or an optical module. Furthermore, recently, silicon photonics is also being used. This has the advantage that the same function can be formed as a very small component by finely processing silicon in the semiconductor manufacturing process. By connecting an optical fiber to a substrate such as an optical waveguide substrate or an optical module, the processed optical signal can be transmitted to a target location.

  The connection between a substrate such as an optical waveguide substrate or an optical module and an optical fiber can be broadly classified into two types. One is a form in which an optical waveguide is formed to the end of the substrate, and optical fibers are connected substantially parallel to the substrate surface. The other is a form in which the optical fibers are connected substantially perpendicular to the substrate surface. This is because surface-type optical elements such as surface-emitting lasers, grating couplers, 45-degree mirrors, and the like have been put into practical use, and it is relatively easy to access the optical waveguide substrate and the optical module in a substantially vertical direction. In any connection form, a single optical fiber or a plurality of optical fibers can be connected together.

  On the other hand, in order to connect optical fibers with low optical loss, high-precision alignment of the optical fibers is necessary. Position accuracy of 5 μm or less is required for a multimode optical fiber and 1 μm or less for a single mode optical fiber. Furthermore, there is also a demand for easily realizing high positional accuracy from the viewpoint of manufacturing. One means for solving this is a structure in which a precisely machined guide pin is inserted into a precisely machined pin hole. That is, two guide pins are provided on the ferrule (fiber block, fiber array) side on which the optical fiber is arranged, pin holes corresponding to the guide pins are provided on the substrate side of the optical waveguide substrate or the optical module, and the guide pins are provided. Insert them into the pin holes and connect them together. As a result, the optical fiber and the substrate are positioned. Since the optical fiber is indirectly positioned using the guide pin, it is desirable that the guide pin serving as a position reference and the corresponding pin hole are formed with high accuracy.

  The method using a guide pin and a pin hole is a method for achieving both high accuracy and simple positioning of an optical fiber. However, in order to ensure accuracy, it is necessary to set the gap (play) provided between the guide pin and the pin hole to a minimum. This means that it is very difficult to insert the guide pin. For this reason, it is widely performed to process the tip end portion of the guide pin or the insertion hole of the pin hole into a tapered shape.

  However, in the connection using guide pins and pin holes, in order to hold the guide pins in the pin holes, the pin holes are deeper than the taper structure provided at the tip part of the guide pins or the insertion hole of the pin holes, or the board It is desirable to make a hole penetrating through. That is, means such as machining such as a drill, long-time wet etching, and laser processing are required. In any case, the deeper the pin hole, the higher the possibility that the position and diameter accuracy of the pin hole will decrease.

  Since silicon photonics is a single mode, highly accurate pin hole processing is required. In order to realize a highly accurate connection using a guide pin and a pin hole, there are the following two problems.

  The first is a highly accurate pin hole processing method. This can be realized by a combination of photolithography technology and dry etching technology. In dry etching, holes formed by highly accurately transferring a resist pattern formed by photolithography can be formed by etching with plasma or gas. Further, dry etching can be performed on the wafer at a time, which is advantageous in terms of manufacturing. However, in such a method using dry etching, deep processing is difficult, and a shallow hole of up to several hundred μm is formed. This makes it difficult to realize a structure that achieves both ease of insertion and high positional accuracy.

  Second, the optical fiber is positioned using guide pins. As described above, if there is no gap between the guide pin and the pin hole, the guide pin cannot be inserted into the pin hole. Therefore, the gap can be a positional error of the optical fiber. Furthermore, since there are tolerances (manufacturing tolerances) in the guide pin diameter and pin hole diameter, this can also be an optical fiber position error.

Here, FIG. 22 is an explanatory diagram of the tolerance between the guide pin and the pin hole, and FIGS. 23 and 24 are explanatory diagrams of the position error due to the tolerance between the guide pin and the pin hole.
For example, a ferrule provided with an optical fiber and a guide pin is connected to an optical element (light emitting unit, light receiving unit, coupler, mirror, etc.) to be optically connected to the optical fiber and a substrate provided with a pin hole. In some cases, there may be tolerances in the diameters of the guide pins and pin holes used. FIG. 22 shows the relationship between the guide pin and pin hole tolerance.

In FIG. 22, the center value of the radius of the guide pin 100 is R ₁ , the tolerance is ± ΔR ₁ , the center value of the radius of the pin hole 200 is R ₂ , and the tolerance is ± ΔR ₂ . That is, the minimum diameter of the guide pin 100 is R ₁ −ΔR ₁ , and the maximum diameter is R ₁ + ΔR ₁ . The minimum diameter of the pin hole 200 is R ₂ −ΔR ₂ , and the maximum diameter is R ₂ + ΔR ₂ . There is a relationship of R ₂ −ΔR ₂ ≧ R ₁ + ΔR ₁ between the diameter of the guide pin 100 and the diameter of the pin hole 200 so that the guide pin 100 can be inserted into the pin hole 200. When a combination of the guide pin 100 having the minimum diameter R ₁ −ΔR ₁ and the pin hole 200 having the maximum diameter R ₂ + ΔR ₂ occurs, a large position error occurs.

FIG. 23 illustrates a case where the pair of guide pins 100 having the minimum diameter R ₁ −ΔR ₁ is positioned in contact with the side wall on the direction S side of the pair of pin holes 200 having the maximum diameter R ₂ + ΔR ₂ . . In this example, a plurality of (for example, 12) optical fibers 110 are aligned between a pair of guide pins 100 with their centers 110 a aligned with the centers 100 a of the guide pins 100. Between the pair of pin holes 200, the optical elements 210 to be optically connected to the respective optical fibers 110 are aligned with their centers 210a aligned with the centers 200a of the pin holes 200.

As shown in FIG. 23, when the pair of guide pins 100 having the minimum diameter R ₁ −ΔR ₁ is positioned in contact with the side wall on the direction S side of the pair of pin holes 200 having the maximum diameter R ₂ + ΔR ₂ , the optical fiber 110 is used. And the optical element 210 are displaced by R ₂ −R ₁ + ΔR ₂ + ΔR ₁ .

In FIG. 24, one guide pin 100 is positioned in contact with the side wall on the direction S side of the corresponding pin hole 200, and the other guide pin 100 is positioned on the direction S of the corresponding pin hole 200. The case where it is located in contact with the side wall on the direction T side opposite to FIG. Similarly to the example of FIG. 23 described above, the guide pin 100 has a minimum diameter R ₁ −ΔR ₁ and the pin hole 200 has a maximum diameter R ₂ + ΔR ₂ . Between the pair of guide pins 100, a plurality of optical fibers 110 are arranged in alignment with their centers 110a aligned with the centers 100a of the guide pins 100. Between the pair of pin holes 200, the optical elements 210 to be optically connected to the respective optical fibers 110 are aligned with their centers 210a aligned with the centers 200a of the pin holes 200.

  In the arrangement as shown in FIG. 24, the positional deviation between the optical fiber 110 and the optical element 210 is reduced as compared with the arrangement as shown in FIG. However, even so, a positional shift that increases from the inside toward the outside occurs between the optical fiber 110 and the optical element 210.

  In connecting optical components using guide pins and pin holes, it is desirable that the influence of the guide pins and pin holes used on the optical components on the positional accuracy between the optical components can be reduced.

In view of the above points, here, an optical device including optical components that are arranged with high positional accuracy and optically connected is realized by using a technique as described below as an embodiment.
First, the first embodiment will be described.

  1 and 2 are diagrams illustrating an example of an optical device according to the first embodiment. FIG. 1 is a schematic perspective view of an essential part of the optical device according to the first embodiment, and FIG. 2 is a schematic cross-sectional view at a position along line L1-L1 in FIG.

1 and 2 includes a ferrule 10 (optical component) and a substrate 20 (optical component). The ferrule 10 and the substrate 20 are arranged opposite to each other and connected.
The ferrule 10 is provided with a plurality of optical fibers 11 (optical elements) and a pair of guide pins 12. Here, a ferrule 10 in which a plurality of (in this example, 12) optical fibers 11 are arranged in a line between a pair of guide pins 12 is illustrated. For example, a cylindrical pin is used for the guide pin 12. The end of the guide pin 12 on the substrate 20 side protrudes from the surface of the ferrule 10 facing the substrate 20 to the substrate 20 side.

  A plurality of (in this example, twelve) optical elements 21 optically connected to the optical fibers 11 of the ferrule 10 and a pair of guide pins 12 of the ferrule 10 are inserted into the substrate 20. A pin hole 22 is provided.

  The optical element 21 provided on the substrate 20 is a surface emitting laser (Vertical Cavity Surface Emitting Laser; VCSEL), a photodiode (Photo Diode; PD), a grating coupler (GC), a 45 degree mirror, or the like. The substrate 20 is an optical waveguide substrate or an optical module provided with such an optical element 21.

  The pin hole 22 provided in the substrate 20 is not a plane circular shape similar to the cross-sectional shape of the guide pin 12 but a hole that is not similar to the cross-sectional shape of the guide pin 12 in plan view. The pin hole 22 has a shape having a region 22a larger than the guide pin 12 to be inserted, and a region 22b communicating with the region 22a and having a width narrowing in the direction P along the surface facing the ferrule 10. Is done. The regions 22b of the pair of pin holes 22 are narrower in the same direction P. Here, the V-shaped region 22b is illustrated in plan view.

  The pin hole 22 can be formed relatively shallow, unlike the pin hole 22 that holds the inserted guide pin alone, and the pin hole 22 and the guide pin 12 inserted into the pin hole 22 are tapered. Is not required. The pin hole 22 can be relatively easily formed with high accuracy using, for example, a photolithography technique.

  In the optical device 1, as shown in FIGS. 1 and 2, a plurality of optical fibers 11 are arranged in a line between a pair of guide pins 12, and a plurality of optical fibers 11 are interposed between a pair of pin holes 22. The optical elements 21 are arranged in a line. As shown in FIG. 1, the guide pin 12 inserted into the pin hole 22 is in contact with and fixed to the side wall of the region 22 b that is narrower in the direction P. In the optical device 1, when the guide pin 12 is thus brought into contact with the side wall of the region 22 b of the pin hole 22, the corresponding optical fiber 11 and the optical element 21 are optically connected. .

Such an assembly of the optical device 1 can be performed as follows.
3 and 4 are diagrams showing an example of an assembling method of the optical device according to the first embodiment. FIG. 3 is a schematic perspective view of a main part of an example of an arrangement process according to the first embodiment, and FIG. 4 is a schematic perspective view of a main part of an example of a connection process according to the first embodiment.

  In assembling the optical device 1, first, the ferrule 10 including the optical fiber 11 and the guide pin 12 as described above, and the substrate 20 including the optical element 21 and the pin hole 22 are prepared.

  As shown in FIG. 3, the prepared ferrule 10 and the substrate 20 are arranged to face each other, and then the ferrule 10 is brought closer to the substrate 20 side (illustrated by a thick arrow in FIG. 3). In this way, the ferrule 10 is moved closer to the substrate 20 side, and the guide pin 12 is inserted into the pin hole 22. When the guide pin 12 is inserted into the pin hole 22, as shown in FIG. 4, the guide pin 12 is first inserted into the region 22a of the pin hole 22 formed larger than that.

  Then, in a state where the guide pin 12 is inserted into the region 22a of the pin hole 22, the ferrule 10 is moved in the direction P, that is, the region 22b side of the pin hole 22 that is narrower in the direction P (a thick arrow in FIG. 4). The guide pin 12 is brought into contact with the side wall of the region 22b. When the side wall of the region 22b of the pin hole 22 is V-shaped as in this example, the side surface of the guide pin 12 comes into contact with one side wall and the other side wall of the V shape. . The state as shown in FIG. 1 is obtained by bringing the guide pin 12 into contact with the side wall of the region 22b.

  The corresponding optical fiber 11 and optical element 21 are formed so as to be optically connected when the guide pin 12 contacts the side wall of the region 22b of the pin hole 22 in this way. As shown in FIG. 1 and FIG. 2 above, when the guide pin 12 is brought into contact with the side wall of the region 22b of the pin hole 22, the corresponding optical fiber 11 and the optical element 21 are aligned and optically connected. An optical device 1 is obtained.

  Thus, first, the guide pin 12 of the ferrule 10 is inserted into the wide region 22a of the pin hole 22 of the substrate 20, and then the ferrule 10 is slid in the direction P, and the width of the guide pin 12 is increased in the direction P. It is made to contact | abut to the side wall of the area | region 22b which becomes narrow. Thereby, both the ease of insertion of the guide pin 12 into the pin hole 22 and the positional accuracy between the ferrule 10 (the optical fiber 11) and the substrate 20 (the optical element 21) are compatible. By adopting a configuration in which the guide pin 12 is shifted in one direction P with respect to the pin hole 22, the direction and amount of positional deviation between the ferrule 10 and the substrate 20 due to the tolerance of the guide pin 12 and the pin hole 22 are clarified and used. Selection and change of the combination of the guide pins 12 can be facilitated.

  In the optical device 1, the pin hole 22 may have a depth that allows the guide pin 12 to be inserted and can be slid after the insertion, and can be formed relatively shallow. The shallow pin hole 22 can be formed with higher dimensional accuracy than a deep pin hole or a pin hole penetrating the substrate 20. Even in the shallow pin hole 22, the region 22 a and the region 22 b as described above are provided in the pin hole 22, and the guide pin 12 is inserted into the region 22 a and then pressed to the side wall of the region 22 b, thereby facilitating insertion. And position accuracy can be achieved.

  Such a shallow pin hole 22 does not have a function of holding the guide pin 12 alone, such as a deep pin hole or a pin hole penetrating the substrate 20. Therefore, after inserting the guide pin 12 into the pin hole 22 and sliding it in the direction P as described above, the ferrule 10 is fixed using a mechanism that keeps pressing in the direction P, or using an adhesive or the like. Adhesive and fixed to the substrate 20.

  Here, as the region 22b of the pin hole 22 whose width becomes narrower in the direction P, the side wall has a V-shaped region in plan view. In addition, as the region 22b whose width becomes narrower in the direction P, a region in which the side wall has an arc shape in a plan view can be provided in the pin hole 22. In this case, when assembling the optical device 1, the guide pin 12 of the ferrule 10 is inserted into the relatively wide region 22 a of the pin hole 22 of the substrate 20, and then slid in the direction P so as to contact the flat arcuate side wall. Be touched. Thereby, the corresponding optical fiber 11 and the optical element 21 are aligned and optically connected.

  Further, here, the optical fiber 11 and the optical element 21 arranged in a line are illustrated. In addition, the above-described guide pin 12 and pin hole 22 are used also for an optical device obtained by connecting a substrate and a ferrule in which optical fibers and optical elements are arranged in a plurality of rows such as two rows and four rows. It is possible to apply the technique.

  In addition, here, the connection between the ferrule 10 and the substrate 20 such as an optical waveguide substrate or an optical module is illustrated, but the above-described method using the guide pin 12 and the pin hole 22 is applied to the connection between various optical components. Is possible.

Next, a second embodiment will be described.
5 and 6 are diagrams illustrating an example of an assembling method of the optical device according to the second embodiment. FIG. 5 is a schematic perspective view of a main part of an example of an arrangement process according to the second embodiment, and FIG. 6 is a schematic perspective view of a main part of an example of a connection process according to the second embodiment.

  7 and 8 are views showing an example of the assembled optical device according to the second embodiment. FIG. 7 is a schematic perspective view of an essential part of the optical device according to the second embodiment, and FIG. 8 is a schematic cross-sectional view of a position along line L2-L2 in FIG.

  In the second embodiment, referring to FIG. 5 to FIG. 8, a ferrule 30 (optical component) including an optical fiber 31 and a guide pin 32, an optical waveguide substrate 40 (optical component) including a grating coupler 41 b and a pin hole 42. ) To obtain the optical device 1A (FIGS. 7 and 8).

  When the optical device 1A is assembled, first, as shown in FIG. 5, a ferrule 30 including an optical fiber 31 (optical element) and a pair of guide pins 32, an optical waveguide 41a, a grating coupler 41b (optical element), and a pair of An optical waveguide substrate 40 having pin holes 42 is prepared. As the guide pin 32 of the ferrule 30, for example, a cylindrical one is used. The pin hole 42 of the optical waveguide substrate 40 is not a planar circular shape that is similar to the cross-sectional shape of the guide pin 32 but is a hole that is not similar to the cross-sectional shape of the guide pin 32 in plan view. In the pin hole 42 of the optical waveguide substrate 40, a region 42 a larger than the guide pin 32 to be inserted, a region communicating with the region 42 a, and a width narrowing in the direction P along the surface facing the ferrule 30. 42b. Here, the V-shaped region 42b is illustrated in plan view.

  Here, an MT (Mechanically Transferable) ferrule is used as the ferrule 30. The surface of the ferrule 30 on the optical waveguide substrate 40 side is polished at an angle that matches the radiation angle of the grating coupler 41b provided on the optical waveguide substrate 40, for example, 8 degrees to 10 degrees, and the guide pins 32 are attached to the ferrule 30 after polishing. Is inserted.

  The optical waveguide substrate 40 is prepared by using a method as exemplified in the following FIGS. 9 to 11 are views showing an example of a method for forming an optical waveguide substrate according to the second embodiment. 9 (A) to 9 (C), 10 (A) to 10 (C), and 11 (A) to 11 (C) respectively show the optical waveguide substrate according to the second embodiment. It is a principal part cross-sectional schematic diagram of each formation process.

First, as shown in FIG. 9A, an SOI wafer (substrate) 43 having a silicon (Si) substrate 43a, a buried oxide (BOX) layer 43b and an SOI (Silicon On Insulator) layer 43c is prepared. The film thickness of the BOX layer 43b can be set to 3 μm, for example. The film thickness of the SOI layer 43c can be 250 nm, for example. A silicon oxide (SiO ₂ ) film 44 is formed on the SOI layer 43 c of the substrate 43 as shown in FIG. 9A. The SiO ₂ film 44 can be formed with a film thickness of 50 nm by chemical vapor deposition (CVD) using silane (SiH ₄ ) as a source gas. After formation of the SiO ₂ film 44, as shown in FIG. 9 (A), a photoresist pattern 45 on the SiO ₂ film 44. The photoresist pattern 45 is formed on the SiO ₂ film 44 corresponding to the formation region of the optical waveguide 41 a provided on the optical waveguide substrate 40.

Subsequently, as shown in FIG. 9B, the SiO ₂ film 44 is etched using the formed photoresist pattern 45 as a mask to form a hard mask pattern 44a. The hard mask pattern 44a can be formed by reactive ion etching (RIE) of the SiO ₂ film 44 using carbon tetrafluoride (CF ₄ ) as an etching gas.

Subsequently, as shown in FIG. 9C, after removing the photoresist pattern 45, the SOI layer 43c is etched using the SiO ₂ film 44 (hard mask pattern 44a) as a mask. The SOI layer 43c can be etched by RIE using hydrogen bromide (HBr) as an etching gas.

The optical waveguide 41a (Si optical waveguide) provided on the optical waveguide substrate 40 is formed on the SOI layer 43c of the substrate 43 by the above steps.
Next, as shown in FIG. 10A, a photoresist pattern 46 having an opening 46a in a region corresponding to the concave portion of the unevenness provided as the grating coupler 41b is formed in the formation region of the grating coupler 41b.

Subsequently, a hard mask pattern is formed by etching the SiO ₂ film 44 using the formed photoresist pattern 46 as a mask, and half etching of the SOI layer 43c is further performed using this as a mask. For example, the SOI layer 43c is half-etched at a depth of 50 nm to 100 nm. Thereafter, the SiO ₂ film 44 is removed. Thus, a grating coupler 41b provided at the end of the optical waveguide 41a as shown in FIG. 10B is formed.

Subsequently, as shown in FIG. 10C, an SiO ₂ film 47 is formed on the substrate 43 on which the optical waveguide 41a and the grating coupler 41b are formed. For example, the SiO ₂ film 47 having a thickness of 1 μm is formed by the CVD method.

  Next, as shown in FIG. 11A, a photoresist pattern 48 having an opening 48a in a region where the pin hole 42 (the pin hole 42 including the region 42a and the region 42b as shown in FIGS. 5 and 6) is formed. Form.

Subsequently, as shown in FIG. 11B, the SiO ₂ film 47 and the BOX layer 43b (total film thickness 4 μm) are etched using the formed photoresist pattern 48 as a mask. For example, the SiO ₂ film 47 and the BOX layer 43b are etched by RIE.

Subsequently, after removing the photoresist pattern 48, as shown in FIG. 11C, the Si substrate 43a is etched using the SiO ₂ film 47 and the BOX layer 43b as a hard mask. For example, the Si substrate 43a is etched at a depth of 100 μm to 500 μm by deep digging RIE. Thereby, the pin hole 42 (area | region 42a and area | region 42b) is formed.

The optical waveguide substrate 40 is prepared by the steps as shown in FIGS.
Returning to FIG. 5 and FIG. 6, the assembly process of the prepared ferrule 30 and the optical waveguide substrate 40 will be described.

  After the ferrule 30 and the optical waveguide substrate 40 are prepared, as shown in FIG. 5, the ferrule 30 and the optical waveguide substrate 40 coated with an adhesive (not shown) are arranged to face each other, and the ferrule 30 is optically guided. It is made to approach the waveguide substrate 40 side (illustrated by a thick arrow in FIG. 5). In this manner, the ferrule 30 is moved closer to the optical waveguide substrate 40, the ferrule 30 is brought into contact with the optical waveguide substrate 40, and the guide pins 32 are inserted into the pin holes 42. When the guide pin 32 is inserted into the pin hole 42, as shown in FIG. 6, the guide pin 32 is first inserted into the region 42a of the pin hole 42 that is formed larger than that. Since the region 42a is formed in a size larger than the guide pin 32, the guide pin 32 can be easily inserted into the pin hole 42 (region 42a).

  Then, with the ferrule 30 in contact with the optical waveguide substrate 40 and the guide pin 32 inserted into the region 42 a of the pin hole 42, the pin hole 42 whose width decreases in the direction P, that is, in the direction P. Slide toward the region 42b (shown by a thick arrow in FIG. 6). As a result, as shown in FIG. 7, the guide pin 32 is brought into contact with the V-shaped side wall of the region 42 b of the pin hole 42.

  In this example, the ferrule 30 is polished at a predetermined angle in order to connect to the optical waveguide substrate 40 provided with the grating coupler 41b, and the guide pins 32 are inclined at a predetermined angle with respect to the substrate plane of the optical waveguide substrate 40. Arranged. Thus, when the guide pin 32 is inclined and arranged, the ferrule 30 is slid in the direction in which the guide pin 32 is tilted, and the guide pin 32 is brought into contact with the side wall of the region 42b of the pin hole 42. . The pin hole 42 is formed so that a region 42 b is provided in the pressing direction of the guide pin 32.

With the guide pin 32 in contact with the side wall of the region 42b of the pin hole 42, the temperature is raised to, for example, 80 ° C. to 120 ° C. to cure the adhesive.
The corresponding optical fiber 31 and the grating coupler 41b are formed so as to be optically connected when the guide pin 32 is in contact with the side wall of the region 42b of the pin hole 42 as described above. By bringing the guide pin 32 into contact with the side wall of the region 42b of the pin hole 42, the corresponding optical fiber 31 and the grating coupler 41b can be aligned and optically connected.

Thereby, an optical device 1A as shown in FIGS. 7 and 8 is obtained.
12 and 13 are explanatory views of a position error due to a tolerance between the guide pin and the pin hole according to the second embodiment.

Since the dimensional accuracy is high when the pin hole 42 is formed by RIE as described above, only the tolerance of the guide pin 32 is considered here. When the center value of the radius of the guide pin 32 is R ₁ and the tolerance is ± ΔR ₁ , the minimum diameter of the guide pin 32 is R ₁ −ΔR ₁ and the maximum diameter is R ₁ + ΔR ₁ .

In FIG. 12, a pair of guide pins 32 (shown by solid lines) having a minimum diameter R ₁ −ΔR ₁ communicate with a relatively wide area 42 a of the corresponding pin hole 42 and are in a plane V shape on the direction P side. The case where it is located in contact with the side wall of the region 42b is illustrated. Between the pair of guide pins 32 having the minimum diameter R ₁ −ΔR ₁ , twelve optical fibers 31 are arranged in alignment with their centers 31 a aligned with the centers 32 a of the guide pins 32.

Further, in FIG. 12, a pair of guide pins 32 (shown by dotted lines) having the maximum diameter R ₁ + ΔR ₁ communicate with a relatively wide region 42a of the corresponding pin hole 42 and are in a plane V shape on the direction P side. The case where it is located in contact with the side wall of the region 42b is illustrated. Between the pair of guide pins 32 having the maximum diameter R ₁ + ΔR ₁ , twelve optical fibers 31 are arranged in alignment with their centers 31 b aligned with the centers 32 b of the guide pins 32.

  In FIG. 12, between a pair of pin holes 42, a grating coupler 41b (shown in a circle for convenience) optically connected to each optical fiber 31 has its center 41ba aligned with a point 42c of the pin hole 42. , Aligned. The region 42b of the pin hole 42 has a plane V shape, and the angle formed by the V-shaped side wall is θ.

In the connection using the guide pin 32 and the pin hole 42, when the diameter of the guide pin 32 varies, the center (32a, 32b) of the guide pin 32 is arranged along the pressing direction of the guide pin 32 (direction P or the opposite direction Q). ) Position changes. As a result, the positional relationship (relative position) between the optical fiber 31 and the grating coupler 41b changes. When the guide pin 32 has the minimum diameter R ₁ −ΔR ₁ and the maximum diameter R ₁ + ΔR ₁ , the deviation of the centers 32 a and 32 b of the optical fiber 31 from the center 41 ba of the grating coupler 41 b is ΔR ₁ / sin ( θ / 2). When the pin hole 42 is designed based on the center value R ₁ of the diameter of the guide pin 32, the influence of tolerance can be suppressed to a small value.

In FIG. 13, the planar arrangement when the guide pin 32 having the minimum diameter R ₁ −ΔR ₁ is inserted into one pin hole 42 and the guide pin 32 having the maximum diameter R ₁ + ΔR ₁ is inserted into the other pin hole 42. Is illustrated. Both guide pins 32 are located in contact with the side wall of the plane V-shaped region 42b on the direction P side, which communicates with the relatively wide region 42a of the corresponding pin hole 42. Between the two guide pins 32, twelve optical fibers 31 are arranged in alignment with their centers 31 c aligned with the centers 32 a and 32 b of both guide pins 32. Between the pair of pin holes 42, a grating coupler 41b optically connected to each optical fiber 31 is arranged in alignment with the center 41ba thereof aligned with the point 42c of the pin hole 42.

As shown in FIG. 13, when the guide pins 32 having the minimum diameter R ₁ −ΔR ₁ and the maximum diameter R ₁ + ΔR ₁ are respectively disposed in the pair of pin holes 42, the two guide pins 32 are provided in the corresponding pin holes 42. It abuts against the side wall of the region 42b on the same direction P side. In this way, the guide pin 32 is shifted in one direction P with respect to the pin hole 42 to suppress the positional deviation between the optical fiber 31 and the grating coupler 41b.

The influence of the tolerance of the guide pin 32 depends on the angle θ of the flat V-shaped side wall with which the guide pin 32 abuts.
FIG. 14 shows an example of the relationship between the angle θ (degrees) and the positional deviation amount (μm) when ΔR ₁ = 1 μm. FIG. 15 shows an example of a planar arrangement of the pin holes 42 of θ = 60 degrees, 90 degrees, and 120 degrees and the guide pins 32 inserted into the pin holes 42, respectively.

As shown in FIG. 14, the larger the angle θ of the pin hole 42 is, the smaller the positional deviation amount becomes. When θ = 180 degrees, the positional deviation amount becomes equal to ΔR ₁ . On the other hand, as can be seen from FIG. 15, the defining force of the guide pin 32 (the ability to hold the guide pin 32 in one place) by the flat V-shaped side wall of the pin hole 42 can be expected as the angle θ decreases.

  In consideration of such a relationship, the angle θ of the pin hole 42 is set. For example, the angle θ is set to 90 degrees or more, preferably 90 degrees to 120 degrees. Thereby, it is possible to suppress the positional deviation between the optical fiber 31 and the grating coupler 41b due to the tolerance of the guide pin 32 and to secure the positional accuracy of the optical fiber 31 with respect to the grating coupler 41b.

  In the second embodiment, the connection between the optical waveguide substrate 40 provided with the grating coupler 41b and the ferrule 30 is illustrated. In addition, the method using the guide pin 32 and the pin hole 42 as described in the second embodiment is based on the fact that a substrate provided with optical elements such as a surface emitting laser, a photodiode, a 45-degree mirror, and the ferrule 30 is used. The connection can be similarly applied.

  Further, here, optical elements such as the optical fibers 31 and the grating coupler 41b arranged in a line are illustrated. In addition, as described in the second embodiment, an optical device obtained by connecting a substrate and a ferrule in which optical fibers and optical elements are arranged in a plurality of rows such as two rows and four rows is also used. It is possible to apply a technique that uses a simple guide pin 32 and pin hole 42.

  Although the connection between the substrate and the ferrule is illustrated here, the method using the guide pin 32 and the pin hole 42 as described in the second embodiment can be applied to the connection between various optical components. Is possible.

Next, a third embodiment will be described.
In the second embodiment, the side wall of the pin hole 42 in the region 42b on which the guide pin 32 abuts is formed in a flat V shape. However, the side wall on which the guide pin 32 abuts on the pin hole 42. Can also be provided with a planar arc-shaped region 42b. An example in which the pin hole 42 including the region 42b whose side wall has a planar arc shape as described above will be described as a third embodiment.

FIG. 16 is a diagram illustrating an example of an optical device according to the third embodiment. FIG. 16 is a schematic perspective view of an essential part of an optical device according to the third embodiment.
In the optical device 1B according to the third embodiment, the pin hole 42 of the optical waveguide substrate 40 is a hole that is not similar to the cross-sectional shape of the guide pin 32 in plan view.

  The pin hole 42 of the optical waveguide substrate 40 of the optical device 1B has a region 42a having a size larger than that of the guide pin 32, and communicates with the region 42a. Arc-shaped region 42b. The optical device 1B is different from the optical device 1A according to the second embodiment in this respect.

  The optical waveguide substrate 40 in which the pin hole 42 including the region 42b having a planar arc shape on the side wall is prepared according to the example of the method (FIGS. 9 to 11) described in the second embodiment. it can.

  The assembly of the optical device 1B can also be performed according to the example of the method (FIGS. 5 to 8) as described in the second embodiment. That is, the prepared optical waveguide substrate 40 and the ferrule 30 provided with the guide pin 32 are opposed to each other, the guide pin 32 is inserted into the region 42a of the pin hole 42, and the ferrule 30 is slid in the direction P to guide the pin. 32 is brought into contact with the planar arc-shaped side wall of the region 42b. By bringing the guide pin 32 into contact with the side wall of the region 42b of the pin hole 42, the corresponding optical fiber 31 and the grating coupler 41b are aligned and optically connected. Thereby, an optical device 1B as shown in FIG. 16 is obtained.

FIGS. 17 and 18 are explanatory views of a position error due to a tolerance between the guide pin and the pin hole according to the third embodiment.
Here, as in the second embodiment, only the tolerance of the guide pin 32 among the tolerances of the guide pin 32 and the pin hole 42 is considered. The center value of the radius of the guide pin 32 is R ₁ and the tolerance is ± ΔR ₁ . The curvature radius of the planar arc-shaped side wall of the region 42b of the pin hole 42 is set to be equal to or larger than the maximum diameter R ₁ + ΔR ₁ of the guide pin 32.

FIG. 17 illustrates a case where a pair of guide pins 32 (shown by solid lines) having a minimum diameter R ₁ −ΔR ₁ are positioned in contact with the side wall of the planar arc-shaped region 42 b of the corresponding pin hole 42. Yes. Between the pair of guide pins 32 having the minimum diameter R ₁ −ΔR ₁ , twelve optical fibers 31 are arranged in alignment with their centers 31 a aligned with the centers 32 a of the guide pins 32.

Further, FIG. 17 exemplifies a case where a pair of guide pins 32 (shown by dotted lines) having the maximum diameter R ₁ + ΔR ₁ are positioned in contact with the side wall of the planar arc-shaped region 42 b of the corresponding pin hole 42. Yes. Between the pair of guide pins 32 having the maximum diameter R ₁ + ΔR ₁ , twelve optical fibers 31 are arranged in alignment with their centers 31 b aligned with the centers 32 b of the guide pins 32.

  Between the pair of pin holes 42, a grating coupler 41b (shown in a circle for convenience) optically connected to each optical fiber 31 is aligned and arranged with its center 41ba aligned with a point 42c of the pin hole 42. ing.

In the third embodiment, by making the side wall of the region 42b of the pin hole 42 into a planar arc shape, the contact between the side wall and the guide pin 32 can be a contact between a circle and a circle. Therefore, a contact state equivalent to that when the angle θ of the planar V-shaped side wall described in the second embodiment is 180 degrees is realized. In both cases where the guide pin 32 has the minimum diameter R ₁ −ΔR ₁ and the maximum diameter R ₁ + ΔR ₁ , the deviation of the centers 32 a and 32 b of the optical fiber 31 from the center 41 ba of the grating coupler 41 b is ΔR ₁ . By making the side wall of the region 42b with which the guide pin 32 abuts into a flat circular arc shape, the positional deviation between the optical fiber 31 and the grating coupler 41b can be suppressed.

In FIG. 18, the planar arrangement when the guide pin 32 having the minimum diameter R ₁ −ΔR ₁ is inserted into one pin hole 42 and the guide pin 32 having the maximum diameter R ₁ + ΔR ₁ is inserted into the other pin hole 42. Is illustrated. Both guide pins 32 are located in contact with the side wall of the planar arc-shaped region 42b of the corresponding pin hole 42. Between the two guide pins 32, twelve optical fibers 31 are arranged in alignment with their centers 31 c aligned with the centers 32 a and 32 b of both guide pins 32. Between the pair of pin holes 42, a grating coupler 41b optically connected to each optical fiber 31 is arranged in alignment with the center 41ba thereof aligned with the point 42c of the pin hole 42.

  As shown in FIG. 18, even when the side wall of the region 42b has a planar arc shape, the positional deviation between the optical fiber 31 and the grating coupler 41b can be suppressed by the configuration in which the guide pin 32 is shifted in one direction P.

  In the third embodiment, the connection between the optical waveguide substrate 40 provided with the grating coupler 41b and the ferrule 30 is exemplified. In addition, the method using the guide pin 32 and the pin hole 42 as described in the third embodiment is based on the fact that a substrate provided with optical elements such as a surface emitting laser, a photodiode, a 45-degree mirror, and the ferrule 30 is used. The connection can be similarly applied.

  Further, here, optical elements such as the optical fibers 31 and the grating coupler 41b arranged in a line are illustrated. In addition, as described in the third embodiment, an optical device obtained by connecting a substrate and a ferrule in which optical fibers and optical elements are arranged in a plurality of rows such as two rows and four rows is also used. It is possible to apply a technique that uses a simple guide pin 32 and pin hole 42.

  Although the connection between the substrate and the ferrule is illustrated here, the method using the guide pin 32 and the pin hole 42 as described in the third embodiment can be applied to the connection between various optical components. Is possible.

Next, a fourth embodiment will be described.
The pressing direction of the guide pins (12, 32) described in the first to third embodiments is not limited to the above example.

19 and 20 are explanatory diagrams of the pressing direction of the guide pin according to the fourth embodiment.
Taking the second embodiment as an example, in the second embodiment, the positional deviation between the optical fiber 31 and the optical element 41 such as the grating coupler 41b due to the tolerance of the guide pin 32 is reduced. Appears in the pressing direction.

  Therefore, for example, as shown in FIG. 19, the direction P in which the guide pin 32 is pressed against the side wall of the pin hole 42 is a direction that obliquely intersects the direction U in which the optical fiber 31 and the optical element 41 are aligned. Alternatively, as shown in FIG. 20, the direction P in which the guide pin 32 is pressed is matched with the direction U in which the optical fiber 31 and the optical element 41 are aligned. A pin hole 42 is provided so that the guide pin 32 can be pressed in the direction P as shown in FIGS. 19 and 20 to contact the flat V-shaped side wall.

  By setting the direction P for pressing the guide pin 32 to the direction P as shown in FIGS. 19 and 20, the appearance direction and amount of the positional deviation between the optical fiber 31 and the optical element 41 due to the tolerance of the guide pin 32 can be adjusted. You can also

  The direction P for pressing the guide pin 12 into the pin hole 22 described in the first embodiment and the direction P for pressing the guide pin 32 into the pin hole 42 described in the third embodiment are also described. The direction P can be set according to the example of FIG. 19 or FIG.

Next, a fifth embodiment will be described.
The shape of the pin hole (22, 42) described in the first to fourth embodiments is not limited to the above example.

  FIG. 21 is an explanatory diagram of a configuration example of a pin hole according to the fifth embodiment. 21A to 21C are schematic perspective views of pin holes and guide pins inserted into the pin holes according to the fifth embodiment.

For example, instead of the pin hole 42 described in the second to fourth embodiments, a pin hole 42 having a shape as shown in FIGS. 21A to 21C can be used.
The pin hole 42 shown in FIG. 21 (A) is rounded at the portion 49a where the V-shaped side wall collides in the pressing direction of the inserted guide pin 32, in the second and fourth embodiments. This is different from the pin hole 42 described in the embodiment. From the viewpoint of easy formation of the pin hole 42 (region 42b), such a rounded portion 49a can also be formed.

  The pin hole 42 shown in FIG. 21B has been described in the third embodiment in that the side wall of the region 42a that is larger than the guide pin 32 has an arcuate portion 49b. Different from the pin hole 42. From the viewpoint of easy formation of the pin hole 42 (region 42a) and ease of insertion of the guide pin 32, such an arc-shaped portion 49b can be provided.

  A pin hole 42 shown in FIG. 21C is a flat rectangular hole. The guide pin 32 is inserted into a region 42a larger than the guide pin 32, is slid toward one apex 49c, and abuts against a V-shaped side wall extending from the apex 49c. Even when the pin hole 42 having such a shape is used, the same effect as that obtained when the pin hole 42 described in the second embodiment or the like is used can be obtained.

Note that the pin holes 22 described in the first embodiment can similarly employ the configurations shown in FIGS. 21 (A) to 21 (C).
Regarding the embodiment described above, the following additional notes are further disclosed.

(Supplementary Note 1) a first optical component having a first pin and a second pin;
A second optical component facing the first optical component and having a first hole and a second hole that are non-similar to the first pin and the second pin in plan view, respectively.
The first pin and the second pin are inserted into the first hole and the second hole, respectively, and are in contact with side walls on the first direction side of the first hole and the second hole. An optical device.

(Supplementary Note 2) The first hole has a first region larger than the first pin, and a second region that communicates with the first region and decreases in width toward the first direction.
The second hole has a third region that is larger than the second pin, and a fourth region that communicates with the third region and decreases in width toward the first direction.
The optical apparatus according to appendix 1, wherein the first pin and the second pin are in contact with side walls of the second region and the fourth region, respectively.

(Additional remark 3) The optical apparatus of Additional remark 1 or 2 characterized by the side wall of the said 1st direction side of the said 1st hole and the said 2nd hole being V shape by planar view.
(Supplementary note 4) The optical device according to supplementary note 1 or 2, wherein side walls in the first direction of the first hole and the second hole are arcuate in plan view.

(Supplementary Note 5) The first optical component and the second optical component each include a first optical element group and a second optical element group,
The first pin and the second pin are brought into contact with the first direction side wall of the first hole and the second hole, respectively, and the first optical element group and the second optical element group are optically connected. The optical device according to any one of appendices 1 to 4, wherein the optical device is connected in a mechanical manner.

(Supplementary note 6) The optical device according to supplementary note 5, wherein each of the first optical element group and the second optical element group is arranged in a direction intersecting the first direction.
(Supplementary note 7) The optical device according to supplementary note 5, wherein each of the first optical element group and the second optical element group is arranged in the first direction.

(Supplementary Note 8) The first pin and the second pin provided on the first optical component are provided on the second optical component facing the first optical component, respectively, and the first pin and the second pin in plan view. Inserting each into a first hole and a second hole of non-similar shapes,
And a step of bringing the inserted first pin and the second pin into contact with side walls on the first direction side of the first hole and the second hole, respectively.

  (Supplementary note 9) The optical device according to supplementary note 8, wherein the step of bringing the first pin and the second pin into contact includes a step of sliding the first optical component in the first direction. Manufacturing method.

(Supplementary Note 10) The first hole includes a first region larger than the first pin, and a second region that communicates with the first region and decreases in width toward the first direction.
The second hole has a third region that is larger than the second pin, and a fourth region that communicates with the third region and decreases in width toward the first direction.
In the step of inserting the first pin and the second pin, the first pin and the second pin are inserted into the first region and the third region, respectively.
In the step of bringing the first pin and the second pin into contact with each other, the first pin and the second pin inserted in the first region and the third region are connected to the second region and the fourth region, respectively. 10. The method of manufacturing an optical device according to appendix 8 or 9, wherein the optical device is brought into contact with a side wall.

(Supplementary Note 11) The first optical component and the second optical component each include a first optical element group and a second optical element group,
The step of bringing the first pin and the second pin into contact with each other brings the first pin and the second pin into contact with the side wall on the first direction side of the first hole and the second hole, respectively. The method of manufacturing an optical device according to any one of appendices 8 to 10, further comprising a step of optically connecting the first optical element group and the second optical element group.

  (Additional remark 12) Each of the said 1st optical element group and the said 2nd optical element group is arranged toward the direction which cross | intersects the said 1st direction, The manufacturing method of the optical apparatus of Additional remark 11 characterized by the above-mentioned. .

  (Additional remark 13) The said 1st optical element group and the said 2nd optical element group are respectively arranged toward the said 1st direction, The manufacturing method of the optical apparatus of Additional remark 11 characterized by the above-mentioned.

1, 1A, 1B Optical device 10, 30 Ferrule 11, 31, 110 Optical fiber 12, 32, 100 Guide pin 20, 43 Substrate 21, 210 Optical element 22, 42, 200 Pin hole 22a, 22b, 42a, 42b Region 31a , 31b, 31c, 32a, 32b, 41ba, 100a, 110a, 200a, 210a Center 40 Optical waveguide substrate 41a Optical waveguide 41b Grating coupler 42c Point 43a Si substrate 43b BOX layer 43c SOI layer 44, 47 SiO ₂ film 44a Hard mask pattern 45, 46, 48 Photoresist pattern 46a, 48a Opening 49a, 49b Site 49c Vertex

Claims (6)

A first optical component having a first pin and a second pin;
A second optical component facing the first optical component and having a first hole and a second hole that are non-similar to the first pin and the second pin in plan view, respectively.
The first pin and the second pin are inserted into the first hole and the second hole, respectively, and are in contact with side walls on the first direction side of the first hole and the second hole. An optical device. The first hole has a first region that is larger than the first pin, and a second region that communicates with the first region and decreases in width toward the first direction,
The second hole has a third region that is larger than the second pin, and a fourth region that communicates with the third region and decreases in width toward the first direction.
The optical device according to claim 1, wherein the first pin and the second pin are in contact with side walls of the second region and the fourth region, respectively.   3. The optical device according to claim 1, wherein side walls in the first direction of the first hole and the second hole are V-shaped in a plan view.   3. The optical device according to claim 1, wherein side walls in the first direction of the first hole and the second hole are arcuate in a plan view. The first optical component and the second optical component each include a first optical element group and a second optical element group,
The first pin and the second pin are brought into contact with the first direction side wall of the first hole and the second hole, respectively, and the first optical element group and the second optical element group are optically connected. The optical device according to claim 1, wherein the optical device is connected in a mechanical manner. A first pin and a second pin provided on the first optical component are provided on a second optical component facing the first optical component, respectively, and the first pin and the second pin are not similar to each other in plan view. Inserting into the first hole and the second hole,
And a step of bringing the inserted first pin and the second pin into contact with side walls on the first direction side of the first hole and the second hole, respectively.

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