JP7478952B2 - Optical module and optical waveguide connection method - Google Patents

Description

This disclosure relates to an optical module and a method for connecting optical waveguides.

In recent years, the use of light has been considered in fields such as high-speed and large-capacity communication and sensing. In particular, a technology called "silicon photonics" has attracted attention, which uses a CMOS (Complementary Metal Oxide Semiconductor) process to form fine optical circuits with optical control functions on silicon substrates, similar to semiconductor electronic circuits. The fine circuits on optical circuit substrates formed by silicon photonics technology include optical input/output units and optical modulators. These are connected by fine thin-wire waveguides on the submicron order. In addition, various optical interfaces are being actively developed to connect external transmission bodies such as optical fibers to the thin-wire waveguides with high precision (fiber-to-chip connection). Diffraction grating-type optical couplers are generally used for the optical input/output units (mechanisms for inputting light from outside the optical circuit) provided on the optical circuit side. When an optical circuit is connected to an optical fiber, "passive alignment," which performs alignment by image recognition without emitting light or operating light-receiving elements, is essential for reducing costs.

Patent Document 1 discloses a method and module in which a diffraction grating, which is a diffraction grating-type optical input/output unit, is provided on an optical wiring board, a hydrophobic film having an opening is formed at a position corresponding to the diffraction grating, and an adhesive layer is formed in this opening, so that the surface tension of the adhesive layer allows the optical fiber to be self-aligned (self-aligned). The optical fiber is connected to the opening by the adhesive layer, and the adhesive layer enables the optical fiber to be self-aligned (self-aligned), and fixes the tip of the optical fiber core to the coupling position with the diffraction grating. As a result, the optical fiber is optically connected to the diffraction grating with low loss and high precision.

JP 2018-17927 A

However, in the conventional technology of Patent Document 1, when the optical fiber is self-aligned by the surface tension of the adhesive layer, the accuracy of the alignment is highly dependent on the positional accuracy of the adhesive layer and the hydrophobic film, and expensive equipment such as a highly accurate micro-application device is required. In addition, because the adhesive layer is interposed on the optical path of the optical fiber, there is a problem in that connection loss occurs due to the influence of the refractive index of the adhesive layer.

Non-limiting examples of the present disclosure contribute to providing an optical module and an optical waveguide connection method that achieves highly efficient optical connection with a low-cost and simple configuration.

An optical module according to one embodiment of the present disclosure comprises a fiber, a fiber guide that holds the fiber, a guide holder that holds the fiber guide and has a first alignment mark, and an optical circuit board that has an optical input/output section and a second alignment mark and is adhered to the guide holder via an adhesive with the second alignment mark facing the first alignment mark , wherein the optical input/output section is provided at a position facing the center of the guide holder, and a blocking section is formed on an end face of the guide holder facing the optical circuit board to prevent the adhesive from penetrating into the center of the guide holder .

According to one embodiment of the present disclosure, it is possible to construct an optical module and an optical waveguide connection method that realizes highly efficient optical connection with a low-cost and simple configuration.

Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and/or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them need be provided to obtain one or more identical features.

FIG. 1 is a cross-sectional view of an optical module 100 according to an embodiment of the present disclosure taken along an XZ plane. FIG. 2 is a plan view of the fiber unit 1 shown in FIG. 1 from below. FIG. 2 is a plan view of the optical circuit board 2 shown in FIG. 1 from above. FIG. 1 shows the application position of adhesive 81 on the optical circuit board 2. FIG. 2 is a diagram showing a state before alignment between the optical circuit board 2 and the fiber unit 1 is performed. FIG. 1 is a diagram showing a state after alignment between the optical circuit board 2 and the fiber unit 1 has been performed. FIG. 13 is a diagram for explaining the effect of the damming groove 31. 1 is a cross-sectional view taken along the XZ plane of a modified example of the optical module 100 according to an embodiment of the present disclosure. FIG. 9 is a plan view of the fiber unit 10 shown in FIG. 8 from below.

A preferred embodiment of the present disclosure will be described in detail below with reference to the attached drawings. In this specification and drawings, components having substantially the same functions are denoted by the same reference numerals to avoid repetitive description. In the following figures, the shapes, thicknesses, lengths, etc. of the components shown in each figure may differ from the actual shapes, thicknesses, lengths, etc. of the components due to the creation of the drawings. Furthermore, the materials of each component are not limited to those described in this embodiment.

1 and subsequent figures, the X-axis direction, the Y-axis direction, and the Z-axis direction represent directions parallel to the X-axis, the Y-axis, and the Z-axis, respectively. The X-axis direction and the Y-axis direction are mutually orthogonal. The X-axis direction and the Z-axis direction are mutually orthogonal. The Y-axis direction and the Z-axis direction are mutually orthogonal. The XY plane represents an imaginary plane parallel to the X-axis direction and the Y-axis direction. The XZ plane represents an imaginary plane parallel to the X-axis direction and the Z-axis direction. The YZ plane represents an imaginary plane parallel to the Y-axis direction and the Z-axis direction. In addition, the direction indicated by the arrow in the X-axis direction is the positive X-axis direction, and the opposite direction to the said direction is the negative X-axis direction. In the Y-axis direction, the direction indicated by the arrow is the positive Y-axis direction, and the opposite direction to the said direction is the negative Y-axis direction. In the Z-axis direction, the direction indicated by the arrow is the positive Z-axis direction, and the opposite direction to the said direction is the negative Z-axis direction. The Z-axis direction is, for example, equal to the vertical direction, the stacking direction, or the up-down direction, and the X-axis direction and the Y-axis direction are, for example, equal to the horizontal direction or the left-right direction. For example, the direction perpendicular to the main surface of the optical circuit board 2 described below is equal to the Z-axis direction, and the optical axis direction of the optical waveguide 51 in the XY plane perpendicular to the Z-axis direction is equal to the X-axis direction.

[Embodiment]
First, the main components constituting an optical module 100 according to an embodiment of the present disclosure will be described with reference to Figures 1, 2, and 3. Figure 1 is a cross-sectional view taken along the XZ plane of the optical module 100 according to an embodiment of the present disclosure, and Figure 2 is a plan view of the fiber unit 1 shown in Figure 1 from below. Figure 3 is a plan view of the optical circuit board 2 shown in Figure 1 from above.

<Configuration of optical module 100>
The optical module 100 includes a fiber unit 1 and an optical circuit board 2. The fiber unit 1 includes a fiber 11 having a core 12 and a cladding 13, a fiber guide 21 which is a component for holding the fiber 11, and a guide holder 22 which is a component for holding the fiber guide 21.

Examples of fiber 11 include single mode fiber, multimode fiber, quartz fiber, plastic fiber, etc.

An opening 21a is formed at the center of the fiber guide 21, with an inner diameter larger than the outer diameter of the cladding 13. The inner diameter is, for example, approximately 10 μm to 15 μm larger than the outer diameter of the cladding 13.

For example, an adhesive is provided between the outer peripheral surface 13a of the cladding 13 and the inner peripheral surface 21a1 that forms the opening 21a of the fiber guide 21. The fiber 11 inserted into the fiber guide 21 is held by the inner peripheral surface 21a1 of the fiber guide 21 via this adhesive.

The end face 21b of the fiber guide 21 in the negative Z-axis direction is mechanically polished, for example, by a method such as CMP (chemical mechanical polishing). The end face 21b is the surface that faces the end face 2a of the optical circuit board 2 in the positive Z-axis direction. By polishing the end face 21b, the processing angle θ, which is the angle between the end face 21b and the outer peripheral surface 21c of the fiber guide 21, is set to, for example, 45° to 90°.

The guide holder 22 is a member that holds the fiber guide 21. The guide holder 22 is a plate-shaped component made of a material that is transparent in the visible range, such as polyvinyl chloride, acrylic resin, melamine resin, urea resin, phenolic resin, epoxy resin, acrylic epoxy resin, polyimide resin, urethane resin, polyester resin, or silicone resin. The guide holder 22 has an opening in its center on the XY plane, with an inner diameter larger than the outer diameter of the fiber guide 21. The dimension of the inner diameter is, for example, approximately 10 μm to 15 μm larger than the outer diameter of the fiber guide 21.

For example, an adhesive is provided between the outer peripheral surface 21c of the fiber guide 21 and the inner peripheral surface 22b of the opening of the guide holder 22. The adhesive holds the fiber guide 21 inserted into the guide holder 22 to the inner peripheral surface 22b of the guide holder 22.

The guide holder 22 has an end face 22c in the positive Z-axis direction, an end face 22a in the negative Z-axis direction, and an inner peripheral surface 22b. The end face 22a in the negative Z-axis direction of the guide holder 22 is flattened by mechanical polishing while maintaining the processing angle θ of the fiber guide 21 described above. The end face 22a faces the end face 2a in the positive Z-axis direction of the optical circuit board 2. The angle between the end face 22a and the inner peripheral surface 22b that forms the opening of the guide holder 22 is set to, for example, 45° to 90°.

The guide holder 22 is formed with a retaining groove 31 and a pair of holder alignment marks 41, 42. Hereinafter, the pair of holder alignment marks 41, 42 will be simply referred to as holder alignment marks 41, 42.

The damming groove 31 is formed on the end surface 22a of the guide holder 22, i.e., the lower surface of the guide holder 22. The damming groove 31 is an annular groove formed, for example, by mechanical cutting using a single crystal diamond bit, so as to surround the inner peripheral surface 22b of the opening of the guide holder 22. The shape of the annular damming groove 31 when viewed in a plan view in the positive Z-axis direction is, for example, circular or elliptical.

The holder alignment marks 41, 42 are a pair of metal films formed on the end surface 22a of the guide holder 22, for example, by patterning using photolithography. Photolithography is a technique in which a pattern (photomask, reticle) that serves as an original plate is irradiated with light radiation such as ultraviolet light and exposed to a silicon substrate coated with a photosensitive agent (photoresist), thereby generating a pattern such as a circuit.

The holder alignment marks 41 and 42 are marks for aligning the fiber unit 1 to the optical circuit board 2 to which the adhesive 81 has been applied. The holder alignment marks 41 and 42 are formed, for example, on the first virtual line 5 at positions that are linearly symmetrical with respect to the second virtual line 6 so as to straddle the center point CP of the guide holder 22. The first virtual line 5 is a virtual line that is parallel to the end face 22a of the guide holder 22 and passes through the center point CP of the guide holder 22. The second virtual line 6 is a virtual line that is parallel to the end face 22a of the guide holder 22, perpendicular to the first virtual line 5, and passes through the center point CP of the guide holder 22.

The center point CP is provided at a position opposite the end of the core 12 of the fiber 11. The holder alignment marks 41, 42 are formed to sandwich the core 12 with the center point CP as the center of the core 12. They are also precisely patterned at positions opposite the pair of substrate alignment marks 71, 72 shown in FIG. 3 in the Z-axis direction. Hereinafter, the pair of substrate alignment marks 71, 72 will be simply referred to as substrate alignment marks 71, 72. Details of the substrate alignment marks 71, 72 will be described later.

The shape of the holder alignment marks 41 and 42 is, for example, a cross shape. However, the shape of the holder alignment marks 41 and 42 is not limited to a cross shape, and may be a square shape, a circular ring shape, a round dot shape, a triangular shape, or any other shape that allows easy visual recognition of the center positions (center points) of the holder alignment marks 41 and 42. In addition, the size of the holder alignment marks 41 and 42 is such that, in the case of a square shape, the length of each of the four sides is 0.1 to 500 [μm], in the case of a cross shape, the length of each of the two lines that are perpendicular to each other is 0.1 to 500 [μm], in the case of a circle, the diameter is 0.1 to 500 [μm], and in the case of a round dot shape, the diameter is 0.1 to 500 [μm]. In addition, in the case of a triangular shape, the size of the holder alignment marks 41 and 42 is such that the length of each of the three sides is 0.1 to 500 [μm]. Forming the holder alignment marks 41 and 42 to such a size is preferable because it makes them easier to recognize and improves alignment accuracy. If the depth of the holder alignment marks 41 and 42 is, for example, 0.01 to 100 μm, it is preferable because alignment accuracy is improved.

The number of holder alignment marks 41, 42 is not limited to two, and may be one or three or more. In terms of improving alignment accuracy, two is preferable, and three or more is more preferable.

For example, when one holder alignment mark 41 is used, if the holder alignment mark 41 is made rectangular and the corresponding substrate alignment mark is made cross-shaped, the holder alignment mark 41 can be superimposed on the substrate alignment mark 71 so that the two mutually perpendicular lines of the cross shape fit within each of the four sides of the rectangle, thereby enabling precise alignment of the guide holder 22 in the X-axis and Y-axis directions.

As another example, if one holder alignment mark is triangular and one corresponding substrate alignment mark is rectangular, the holder alignment mark can be superimposed on the substrate alignment mark so that one of the three sides of the triangle overlaps one of the four sides of the square, thereby enabling precise alignment of the guide holder 22 in the X-axis and Y-axis directions.

In addition, when three holder alignment marks are used, the three holder alignment marks are arranged, for example, straddling the center point CP of the guide holder 22, coaxially around the center point CP, and at equal circumferential positions. The three corresponding substrate alignment marks are then similarly arranged, so that the three holder alignment marks can be superimposed on the three substrate alignment marks. This allows for more precise alignment of the guide holder 22 in the X-axis and Y-axis directions.

The optical circuit board 2 includes board alignment marks 71, 72, an optical waveguide 51, and an optical input/output section 61.

The substrate alignment marks 71 and 72 are a pair of metal films formed on the end surface 2a of the optical circuit board 2, for example, by patterning using photolithography. The substrate alignment marks 71 and 72 are marks for aligning the fiber unit 1 to the optical circuit board 2. The substrate alignment marks 71 and 72 are formed, for example, on the first virtual line 5a at positions that are linearly symmetrical with respect to the second virtual line 6a so as to straddle the optical input/output unit 61. The first virtual line 5a is a virtual line that is parallel to the end surface 2a of the optical circuit board 2 and passes through the optical input/output unit 61. The second virtual line 6a is a virtual line that is parallel to the end surface 2a of the optical circuit board 2, perpendicular to the first virtual line 5a, and passes through the centers of the optical input/output unit 61 and the optical waveguide 51. The second virtual line 6 is equal to the optical axis of the optical waveguide 51.

The shape of the substrate alignment marks 71 and 72 is, for example, a square. However, the shape of the substrate alignment marks 71 and 72 is not limited to a square, and may be a cross, an annular circle, a round dot, a triangle, or any other shape that allows easy visual recognition of the center position (center point) of each of the substrate alignment marks 71 and 72. In addition, the size of the substrate alignment marks 71 and 72 is such that, in the case of a square, the length of each of the four sides is 0.1 to 500 μm, in the case of a cross, the length of each of the two lines that are perpendicular to each other is 0.1 to 500 μm, in the case of a circle, the diameter is 0.1 to 500 μm, and in the case of a round dot, the diameter is 0.1 to 500 μm. In addition, in the case of a triangle, the size of the substrate alignment marks 71 and 72 is such that the length of each of the three sides is 0.1 to 500 μm. Forming the substrate alignment marks 71, 72 to such a size is preferable because it makes them easier to recognize and improves alignment accuracy. If the depth of the substrate alignment marks 71, 72 is, for example, 0.01 to 100 μm, it is preferable because alignment accuracy is improved.

The number of substrate alignment marks 71, 72 is not limited to two, and may be one or three or more. In terms of improving alignment accuracy, two is preferable, and three or more is even more preferable.

An adhesive 81 is applied to the optical circuit board 2, and this adhesive 81 is, for example, a photocurable resin. Details of the position where the adhesive 81 is applied will be described later.

After the adhesive 81 is applied to the optical circuit board 2, the fiber unit 1 is attached to the optical circuit board 2 via the adhesive 81 with the holder alignment marks 41, 42 aligned with the board alignment marks 71, 72 as references.

At this time, the adhesive 81 spreads toward the center of the guide holder 22, but because part of the adhesive 81 enters the retaining groove 31, it is possible to prevent the adhesive 81 from adhering to the tip of the core 12 of the fiber 11 that is placed in the center of the guide holder 22.

<Optical waveguide connection method>
Next, the optical waveguide connection method for realizing the optical module 100 of the present disclosure will be described in detail with reference to Fig. 4 etc. Fig. 4 is a diagram showing the application position of the adhesive 81 on the optical circuit board 2.

First, as shown in FIG. 4, adhesive 81 is applied in a ring shape to the end surface 2a of the optical circuit board 2. Specifically, the adhesive 81 is applied so that its inner diameter 81a is larger than the outer diameter of the ring-shaped retaining groove 31 formed in the guide holder 22 shown in FIG. 2, and its outer diameter 81b is smaller than the outer diameter of the guide holder 22.

Next, the fiber unit 1 is attached to the optical circuit board 2 to which the adhesive 81 has been applied, and the optical circuit board 2 and the fiber unit 1 are aligned. The alignment will be described with reference to Figures 5 and 6.

Figure 5 shows the state before alignment between the optical circuit board 2 and the fiber unit 1, and Figure 6 shows the state after alignment between the optical circuit board 2 and the fiber unit 1.

The fiber unit 1 is placed on the optical circuit board 2 so that the positions of the board alignment marks 71, 72 of the fiber unit 1 coincide with the approximate positions of the holder alignment marks 41, 42 of the optical circuit board 2. As a result, the fiber unit 1 is attached to the optical circuit board 2 with the annular adhesive 81 applied to the optical circuit board 2 positioned outside the retaining groove 31 of the fiber unit 1.

At this time, since the guide holder 22 is a material that is transparent in the visible range, the amount of misalignment between the fiber unit 1 and the optical circuit board 2 in a direction parallel to the XY plane can be observed, for example, from the upper side of the guide holder 22 shown in FIG. 5 by using an imaging means such as a camera. This amount of misalignment can be calculated from the distance from the center position of the holder alignment marks 41, 42 to the center position of the board alignment marks 71, 72, so the amount of misalignment can be calculated based on the positional relationship between these marks imaged by a camera or the like. Then, based on the calculated amount of misalignment, the fiber unit 1 is aligned in the direction 101 of the arrow shown in FIG. 5. At this time, since an adhesive 81 is interposed between the fiber unit 1 and the optical circuit board 2, the adhesive's fluidity can be utilized to easily align the fiber unit 1 in liquid.

Here, an example of aligning the fiber unit 1 is shown, but if the position can be adjusted, the optical circuit board 2 may also be aligned.

When the position is corrected by alignment, the central positions of the holder alignment marks 41, 42 and the substrate alignment marks 71, 72 coincide as shown in Figure 6, and as a result, the core 12 and the optical input/output section 61 are optically connected with high precision so that the optical transmission efficiency is high.

Next, the effect of the damming groove 31 will be described with reference to FIG. 7. FIG. 7 is a diagram for explaining the effect of the damming groove 31. The upper side of FIG. 7 shows a cross-sectional view of the optical module 100 before the alignment operation. The lower side of FIG. 7 shows a cross-sectional view of the optical module 100 after the alignment operation.

When the fiber unit 1 is adhered to an approximate position on the optical circuit board 2, the adhesive 81 is present outside the damming groove 31, as shown in the upper diagram of FIG. 7. When the position of the fiber unit 1 is then corrected in the direction 101 indicated by the arrow, as shown in the lower diagram of FIG. 7, a part of the adhesive 81 penetrates into the damming groove 31, blocking the flow of the adhesive 81 into the inside of the damming groove 31. This prevents the adhesive 81 from penetrating into the area where the core 12 of the fiber 11 and the optical circuit board 2 face each other. This enables optical connection between the core 12 of the fiber 11 and the optical input/output unit 61 on the optical circuit board 2. As a result, highly efficient optical connection can be achieved without being affected by the refractive index of the adhesive 81, etc.

Finally, the adhesive 81 is cured to fix the fiber unit 1 to the optical circuit board 2. This realizes an optical connection between the core 12 of the fiber 11 and the optical waveguide 51 on the optical circuit board 2. Furthermore, according to the optical module and optical waveguide connection method of this embodiment, the cladding 13 of the fiber 11 can be aligned to the optical input/output section 61 by using an alignment mark without using expensive equipment such as a highly accurate micro-application device as in the conventional technology, so that a highly efficient optical connection can be realized with a low-cost and simple configuration.

<Modifications of the Optical Module 100>
A modified example of the present embodiment will be described below with reference to Fig. 8 and Fig. 9. Fig. 8 is a cross-sectional view along the XZ plane of a modified example of the optical module 100 according to the embodiment of the present disclosure. Fig. 9 is a plan view of the fiber unit 10 shown in Fig. 8 from below. In Fig. 8 and Fig. 9, the same reference numerals are used for the same components as those shown in Fig. 1 and Fig. 2, and the description thereof will be omitted.

The optical module 100 in this modified example has a fiber unit 1A instead of the fiber unit 1.

In the guide holder 22 of the fiber unit 1A, a step portion 31A is formed instead of the damming groove 31. The step portion 31A is formed so as to surround the inner peripheral surface 22b of the opening of the guide holder 22, for example, by mechanical cutting using a single crystal diamond bit. The radial thickness from the inner peripheral surface 22b of the opening to the step portion 31A is, for example, 0.5 to 5 mm. By forming the step portion 31A, an inner region and an outer region having different thicknesses in the Z-axis direction are formed in 22a of the guide holder 22. The thickness of the inner region of the guide holder 22 is greater than the thickness of the outer region of the guide holder 22.

By providing the step portion 31A, when the position of the fiber unit 1 is corrected after the fiber unit 1 has been adhered to an approximate position on the optical circuit board 2, the step portion 31A blocks the flow of adhesive 81 into the inner region of the step portion 31A. This makes it possible to prevent the adhesive 81 from entering the region where the core 12 of the fiber 11 and the optical circuit board 2 face each other.

In this way, by providing the step portion 31A, the same effect can be obtained as when the dam groove 31 is provided. Furthermore, compared to when the dam groove 31 is provided, the surface on which the holder alignment marks 41, 42 and the board alignment marks 71, 72 can be formed is wider, improving the design freedom of the guide holder 22 while improving the fixing strength of the fiber unit 1 to the optical circuit board 2.

For example, it is understood that the following aspects also fall within the technical scope of this disclosure:

(1) The optical module 100 includes a fiber 11, a fiber guide 21 that holds the fiber 11, a guide holder 22 that holds the fiber guide 21 and has a first alignment mark (holder alignment marks 41, 42), and an optical circuit board 2 that has an optical input/output section 61 and a second alignment mark (substrate alignment marks 71, 72) and is bonded to the guide holder 22 via an adhesive 81 with the second alignment mark facing the first alignment mark.

(2) The end face (second end face 22a) of the guide holder 22 facing the optical circuit board 2 is provided with a blocking portion (blocking groove 31, step portion 31A) that blocks the adhesive 81 from penetrating into the center of the guide holder 22.

(3) The damming portion is an annular groove formed to surround the center of the guide holder 22.

(4) The stopper portion is a step formed to surround the center of the guide holder 22.

(5) The guide holder 22 is made of a material that is transparent in the visible range.

(6) The first alignment mark and the second alignment mark are formed from a metal film.

(7) The optical waveguide connection method includes a coating step of coating an adhesive 81 on an optical circuit board 2 having an input/output section 61 and a first alignment mark (board alignment marks 71, 72), a mounting step of mounting a guide holder 22 that holds a fiber guide 21 and has a second alignment mark (holder alignment marks 41, 42) facing the first alignment mark on the adhesive 81, and an alignment step of aligning the second alignment mark to the position of the first alignment mark.

(8) The end face (second end face 22a) of the guide holder 22 facing the optical circuit board 2 is formed with blocking portions 31, 31A that block the infiltration of the adhesive 81 into the center of the guide holder 22. When the second alignment mark is aligned with the position of the first alignment mark in the alignment process, the blocking portions 31 block the infiltration of the adhesive 81 into the portion where the core of the fiber 11 faces the optical input/output unit 61.

(9) The dam portion used in the optical waveguide connection method is an annular groove formed to surround the center of the guide holder 22.

(10) The stopper portion used in the optical waveguide connection method is a step formed to surround the center of the guide holder 22.

(11) The guide holder 22 used in the optical waveguide connection method is made of a material that is transparent in the visible range.

(12) The first alignment marks 71, 72 and the second alignment marks 41, 42 used in the optical waveguide connection method are formed from a metal film.

An embodiment of the present disclosure is suitable for semiconductor devices. In addition, the optical module and optical waveguide connection method according to the present disclosure can permanently connect a fiber to an optical waveguide on an optical circuit board with high precision, and therefore can be applied in fields such as high-speed optical communications, as typified by silicon photonics, and high-precision sensing using laser light.

Reference Signs List 1, 1A: Fiber unit 2: Optical circuit board 2a: End face 10: Fiber unit 11: Fiber 12: Core 13: Cladding 13a: Outer surface 21: Fiber guide 21a: Opening 21a1: Inner surface 21b: End face 21c: Outer surface 22: Guide holder 22a: End face 22b: Inner surface 22c: End face 31: Retaining groove 31A: Step portion 41, 42: Holder alignment mark 51: Optical waveguide 61: Optical input/output portion 71, 72: Board alignment mark 81: Adhesive 100: Optical module

Claims (10)

Fiber,
a fiber guide for holding the fiber;
a guide holder that holds the fiber guide and has a first alignment mark;
an optical circuit board having an optical input/output unit and a second alignment mark, and being bonded to the guide holder via an adhesive in a state in which the second alignment mark faces the first alignment mark;
In an optical module comprising:
the optical input/output unit is provided at a position facing a center portion of the guide holder,
An optical module, comprising: an end surface of the guide holder facing the optical circuit board, the end surface being provided with a blocking portion for blocking the adhesive from penetrating into the center of the guide holder. 2. The optical module according to claim 1 , wherein the stopper portion is an annular groove formed so as to surround a center portion of the guide holder. 2. The optical module according to claim 1 , wherein the stopper portion is a step formed so as to surround a center portion of the guide holder. The optical module according to claim 1 , wherein the guide holder is made of a material that is transparent in the visible range. The optical module according to claim 1 , wherein the first alignment mark and the second alignment mark are formed of a metal film. a coating step of coating an adhesive on an optical circuit board having an optical input/output unit and a first alignment mark;
a mounting step of mounting a guide holder, the guide holder holding a fiber guide and having a second alignment mark facing the first alignment mark, on the adhesive;
an alignment step of aligning the second alignment mark to a position of the first alignment mark;
An optical waveguide connection method comprising :
the optical input/output unit is provided at a position facing a center portion of the guide holder,
a blocking portion is formed on an end surface of the guide holder facing the optical circuit board to block the adhesive from entering a center portion of the guide holder;
an optical waveguide connection method, in which, in the alignment process, when the second alignment mark is aligned to the position of the first alignment mark, the infiltration of the adhesive into the portion where the core of the fiber held in the fiber guide faces the optical input/output portion is prevented by the blocking portion. 7. The optical waveguide connection method according to claim 6 , wherein the blocking portion is an annular groove formed so as to surround a center portion of the guide holder. 7. The optical waveguide connection method according to claim 6 , wherein the stopper portion is a step formed so as to surround a center portion of the guide holder. 9. The optical waveguide connection method according to claim 6 , wherein the guide holder is made of a material that is transparent in the visible range. 10. The optical waveguide connection method according to claim 6 , wherein the first alignment mark and the second alignment mark are formed of a metal film.

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