JP2014063110A - Optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical module that is able to restrict displacements of a pressing plate and an optical fiber and able to facilitate the laying of the optical fiber.SOLUTION: An optical fiber accommodation groove 3 formed in an optical waveguide 4 is formed to accommodate the entire leading end portion of an optical fiber 2 such that the optical fiber 2 does not project from the surface of the optical waveguide 4. Additionally, the optical fiber accommodation grove 3 is formed such that when the leading end portion of the optical fiber 2 is accommodated in the optical fiber accommodation groove 3 and the opening of the optical fiber accommodation groove 3 is covered with a pressing plate 6, a distance by which the leading end portion of the optical fiber 2 is allowed to move in its radial direction is not more than 20 μm.

Description

  The present invention relates to an optical module in which an optical fiber and an optical element are optically connected via an optical waveguide.

  In the surface light emitting element and the surface light receiving element, light is incident and emitted in a direction perpendicular to the surface of the substrate to be mounted. However, if the optical fiber is provided perpendicular to the surface of the substrate, it becomes difficult to handle the optical fiber. End up. Therefore, the optical element and the optical fiber are optically connected via an optical waveguide having an optical axis conversion function so that the optical fiber can be arranged in parallel to the surface of the substrate even if a surface light emitting element or a surface light receiving element is used. An optical module connected to is known.

  In such an optical module, an optical waveguide is formed on the surface of the substrate on which the optical element is mounted (flexible printed circuit board) on the side opposite to the side on which the optical element is mounted, and the position facing the light emitting portion or the light receiving portion of the optical element. A reflection mirror for optical axis conversion is formed on the core of the optical waveguide, and the optical element and the core of the optical waveguide are optically coupled via the reflection mirror.

  The optical waveguide is formed with an optical fiber housing groove for housing the tip of the optical fiber, and the tip surface of the optical fiber housed in the optical fiber housing groove is connected to the inner wall on the tip side of the optical fiber housing groove where the core is exposed. The optical fiber core and the optical waveguide core are optically coupled to each other.

  The optical fiber housing groove is usually formed to be shallower than the diameter of the tip of the optical fiber, and an adhesive is applied to the inside of the optical fiber housing groove or around the optical fiber, and the optical fiber is pressed by a holding plate. By curing the adhesive, the optical fiber is fixed to the optical waveguide (the optical fiber is not fixed to the optical waveguide, but there is Patent Document 1 as a similar technique).

  For example, as in Patent Document 2, there is a case where the optical fiber is fixed only with an adhesive without using a pressing plate. However, particularly in a small-sized optical module, the tip of the optical fiber escapes when mounting the optical fiber. It is essential to have a pressure plate that holds it down.

JP 2004-93730 A JP-A-5-11122

  However, in the conventional optical module, as shown in FIG. 6, when the number of optical fibers 61 is as small as one (or several), the protruding portion of the optical fiber is not accommodated in the optical fiber accommodating groove 63 of the optical waveguide 62. The pressing plate 64 may interfere with 61 and the pressing plate 64 may tilt. As a result, when the pressing plate 64 is pressed, the pressing plate 64 escapes to the side and the pressing plate 64 is displaced, or the pressing by the pressing plate 64 is not sufficient, and the optical fiber 61 is displaced. In some cases, there is a problem that the mounting operation of the optical fiber 61 is not easy (note that an optical element, a substrate, and the like are omitted in FIG. 6).

  The positional displacement of the pressing plate 64 causes a change in size, and particularly in a small optical module, it causes a deterioration in yield such as difficulty in housing in the housing. Further, the positional deviation of the optical fiber 61 causes a positional deviation between the core of the optical fiber 61 and the core of the optical waveguide 62, and increases optical loss.

  Accordingly, an object of the present invention is to provide an optical module that solves the above-described problems, can suppress the displacement of the pressing plate and the optical fiber, and can facilitate the mounting operation of the optical fiber.

  The present invention has been devised to achieve the above-described object, and includes an optical fiber, an optical waveguide in which an optical fiber housing groove for housing a tip portion of the optical fiber is formed, and the optical fiber accommodated in the optical waveguide. By filling and hardening the optical fiber housing groove, an adhesive that fixes the optical fiber to the optical fiber housing groove and an upper portion of the optical fiber housing groove that contains the optical fiber and is filled with the adhesive are covered. And a pressing plate that suppresses the displacement of the optical fiber, and the tip surface of the optical fiber received in the optical fiber receiving groove is disposed on the tip side of the optical fiber receiving groove where the core is exposed. An optical module configured such that the core of the optical fiber and the core of the optical waveguide are optically coupled to each other by being abutted against an inner wall, and the optical fiber housing groove includes the optical fiber The optical fiber housing groove is formed so as to accommodate the entire distal end portion of the optical fiber so that the optical fiber does not protrude from the surface of the waveguide, and the optical fiber housing groove accommodates the distal end portion of the optical fiber. The optical module is formed so that a distance in which the optical fiber is allowed to move in the radial direction when the opening is closed with the pressing plate is 20 μm or less.

  The optical fiber accommodation groove may be formed in a rectangular shape in a cross-sectional view, and may be formed such that a difference between a width and depth thereof and a diameter of a tip portion of the optical fiber is 0 μm or more and 20 μm or less.

  The optical fiber may be housed in the optical fiber housing groove at the tip thereof together with the coating, and the thickness of the coating may be less than 15 μm.

  The adhesive is filled in the distal end portion of the optical fiber housing groove, and the optical waveguide is connected to the distal end portion of the optical fiber housing groove, and the adhesive of the adhesive is cured by curing shrinkage when the adhesive is cured. An adhesive supply groove for supplying the adhesive may be formed at the tip of the optical fiber housing groove so that peeling does not occur.

  An adhesive collecting groove for collecting the adhesive pushed out when the pressing plate is provided is formed on both sides of the optical fiber housing groove, the adhesive collecting groove, the adhesive supplying groove, May be connected.

  A dummy optical fiber for reinforcing the optical waveguide may be accommodated in the adhesive collecting groove.

  The adhesive may have a viscosity of 2000 mPa · s or less.

  Forming an adhesive filling portion in which the optical fiber accommodation groove is expanded in the width direction at a position spaced from the tip of the optical fiber accommodation groove, filling the adhesive filling portion with the adhesive, and the optical fiber accommodation groove; You may make it not fill with an adhesive agent at the front-end | tip part.

  The adhesive pushed out when the pressing plate is provided between the tip of the optical fiber housing groove and the adhesive filling portion or at the adhesive filling portion does not reach the tip of the optical fiber housing groove. In addition, an adhesive release groove for releasing the adhesive may be connected.

  The width of the adhesive relief groove may be narrower than the width of the optical fiber housing groove.

  The adhesive may have a viscosity of 1000 mPa · s or more.

  ADVANTAGE OF THE INVENTION According to this invention, the optical module which can suppress the position shift of a pressing plate and an optical fiber, and can make the mounting operation | work of an optical fiber easy can be provided.

It is a figure which shows the optical module which concerns on one embodiment of this invention, (a) is a top view, (b) is the 1B-1B sectional view taken on the line. It is a top view which shows the modification of the optical module of FIG. It is a top view which shows the modification of the optical module of FIG. It is a top view which shows the optical module which concerns on other embodiment of this invention. (A), (b) is a top view which shows the modification of the optical module of FIG. It is a figure explaining the subject of the conventional optical module.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1A and 1B are diagrams showing an optical module according to the present embodiment, in which FIG. 1A is a plan view and FIG. 1B is a sectional view taken along line 1B-1B.

  As shown in FIGS. 1A and 1B, an optical module 1 includes an optical fiber 2, an optical waveguide 4 in which an optical fiber housing groove 3 in which the tip of the optical fiber 2 is housed, and an optical waveguide. An optical element 5 that is optically connected to the optical fiber 2 via 4 and an optical fiber housing groove 3 that houses the optical fiber 2 are filled and cured, thereby fixing the optical fiber 2 to the optical fiber housing groove 3. An adhesive (not shown), and a pressing plate 6 that is provided so as to cover the upper portion of the optical fiber housing groove 3 that contains the optical fiber 2 and is filled with the adhesive, and suppresses the displacement of the optical fiber 2. I have.

  In the present embodiment, a surface light emitting element such as a VCSEL (Vertical Cavity Surface Emitting LASER) or a surface light receiving element such as a photodiode is used as the optical element 5. The optical element 5 is mounted on one surface of a substrate (flexible printed circuit board (FPC)) 7, and an optical waveguide 4 is formed on the other surface of the substrate 7. On one surface of the substrate 7, a driver IC that drives the optical element 5 (when the optical element 5 is a light emitting element) or an amplifier IC that amplifies an electrical signal from the optical element 5 (when the optical element 5 is a light receiving element) ) And the like are mounted, but are omitted in FIG.

  For example, the substrate 7 is mounted on a base substrate (rigid substrate) via an FPC connector or the like, and is configured to be electrically connected to an external communication device or the like via an electrical connector provided on the base substrate. . Further, in the optical module 1, a housing is provided so as to cover the distal end portion of the optical fiber 2, the optical waveguide 4, the optical element 5, the pressing plate 6, the substrate 7, and the like, but the illustration is omitted in FIG. Yes.

  The optical waveguide 4 is formed in a rectangular shape in plan view. The length of one side in plan view of the optical waveguide 4 is, for example, about 0.8 to 3 mm. A linear optical fiber housing groove 3 for housing the optical fiber 2 is formed on the surface of the optical waveguide 4 (on the side opposite to the substrate 7).

  One end of the core 4a of the optical waveguide 4 is exposed from the inner wall on the distal end side of the optical fiber housing groove 3 (the inner wall on the lower side of FIG. 1A), and the optical fiber housing groove 3 from which the core 4a is exposed. The core of the optical fiber 2 and the core 4a of the optical waveguide 4 are optically coupled to each other by abutting the tip surface of the optical fiber 2 accommodated in the optical fiber accommodating groove 3 with the inner wall on the distal end side of the optical fiber. Yes.

  A reflection mirror 4b for optical axis conversion is formed on the core 4a at a position facing the light emitting part or the light receiving part of the optical element 5, and the optical element 5 and the optical waveguide 4 are connected via the reflection mirror 4b. The core 4a is optically coupled.

  The pressing plate 6 is formed in a rectangular shape that is slightly smaller than the optical waveguide 4 in plan view. The pressing plate 6 is made slightly smaller than the optical waveguide 4 in plan view so that the pressing plate 6 does not protrude as far as possible to the side of the optical waveguide 4 even when a displacement occurs when the pressing plate 6 is provided. This is to improve the yield.

  For example, an ultraviolet curable resin can be used as the adhesive. The optical fiber 2 is accommodated in the optical fiber accommodation groove 3, the adhesive is filled in the optical fiber accommodation groove 3, and the adhesive is irradiated with ultraviolet rays while the pressing plate 6 is pressed so as to close the optical fiber accommodation groove 3. For example, the optical fiber 2 and the pressing plate 6 are fixed (mounted) to the optical waveguide 4 by curing the adhesive.

  Here, a case where one optical fiber 2 is used will be described, but it is of course possible to provide a plurality of optical fibers 2. In this case, an optical element array may be used as the optical element 5, and a plurality of optical fiber accommodation grooves 3 corresponding to the plurality of optical fibers 2 may be formed in the optical waveguide 4.

  Now, in the optical module 1 according to the present embodiment, the optical fiber accommodation groove 3 is formed so as to accommodate the entire tip of the optical fiber 2 so that the optical fiber 2 does not protrude from the surface of the optical waveguide 4, and When the distal end portion of the optical fiber 2 is accommodated in the optical fiber accommodation groove 3 and the opening of the optical fiber accommodation groove 3 is closed with the pressing plate 6, the distal end portion of the optical fiber 2 is in the radial direction (FIG. 1B). The distance allowed to move in the direction parallel to the plane of the drawing is 20 μm or less.

  More specifically, in the present embodiment, the optical fiber housing groove 3 is formed in a rectangular shape in a sectional view, and the width W and the depth D thereof are equal to or larger than the diameter d of the tip end portion of the optical fiber 2. Thus, the entire tip of the optical fiber 2 is accommodated in the optical fiber accommodation groove 3.

  In the present embodiment, the difference (Wd and Dd) between the width W and depth D of the optical fiber housing groove 3 and the diameter d of the tip of the optical fiber 2 is set to 0 μm or more and 20 μm or less. Thus, when the opening of the optical fiber housing groove 3 is closed by the pressing plate 6, the distance that the tip of the optical fiber 2 is allowed to move in the radial direction is set to 20 μm or less. If the distance that the tip of the optical fiber 2 is allowed to move in the radial direction when the opening of the optical fiber housing groove 3 is closed with the pressing plate 6 is greater than 20 μm, the core of the optical fiber 2 and the optical waveguide In some cases, the optical loss due to the shift of the 4 cores 4a becomes too large, and the yield deteriorates.

  In order to fill the optical fiber housing groove 3 with a sufficient adhesive and to prevent the optical fiber 2 from protruding from the optical fiber housing groove 3 due to the influence of processing accuracy, the depth of the optical fiber housing groove 3 is reduced. The difference between the length D and the diameter d of the tip of the optical fiber 2 is more preferably 5 μm or more. Further, in order to minimize the positional deviation between the core of the optical fiber 2 and the core 4a of the optical waveguide 4, the core of the optical waveguide 4 is centered in the width direction and the depth direction on the inner wall on the distal end side of the optical fiber housing groove 3. It is desirable to form 4a.

  In the present embodiment, the optical fiber accommodation groove 3 is formed in a rectangular shape in a sectional view, but the shape of the optical fiber accommodation groove 3 is not limited to this. However, there is a need for a gap for filling the adhesive between the optical fiber 2 and the optical fiber housing groove 3, and if the volume of the optical fiber housing groove 3 is increased too much, the strength of the optical waveguide 4 decreases. In view of this, and the workability and the like, it can be said that it is desirable to form the optical fiber housing groove 3 in a rectangular shape in a sectional view.

  In the conventional optical module, the coating at the tip of the optical fiber 2 is often removed and accommodated in the optical fiber accommodation groove 3 in a bare wire state. However, the optical fiber 2 in the bare wire state is difficult to handle and is reliable. In this embodiment, the tip of the optical fiber 2 is accommodated in the optical fiber accommodation groove 3 together with the coating. However, in this case, if the coating is too thick, it may cause a core misalignment due to variations in the coating thickness. Therefore, it is desirable to use the optical fiber 2 having a coating thickness of less than 15 μm. .

  In the optical module 1 according to the present embodiment, the tip of the optical fiber housing groove 3 is also filled with an adhesive. As the adhesive, it is desirable to use a refractive index equivalent to that of the core of the optical fiber 2 and the core 4 a of the optical waveguide 4. The adhesive filled in the tip portion of the optical fiber housing groove 3 serves as a refractive index matching agent, so that the tip surface of the optical fiber 2 is rough to some extent (the tip surface of the optical fiber 2 is somewhat uneven) However, it is possible to suppress light loss between the optical fiber 2 and the optical waveguide 4 by supplementing with an adhesive.

  When the adhesive is filled in the tip portion of the optical fiber housing groove 3, curing shrinkage when the adhesive is cured becomes a problem. When peeling occurs between the distal end surface of the optical fiber 2 and the inner wall on the distal end side of the optical waveguide 4 due to the curing shrinkage of the adhesive (between both cores), irregular reflection occurs on the separated surface and light loss occurs. This is because it becomes large.

  Therefore, in the present embodiment, the tip of the optical fiber housing groove 3 is connected to the optical waveguide 4 at the tip of the optical fiber housing groove 3 so that the adhesive does not peel off due to curing shrinkage when the adhesive is cured. An adhesive supply groove 8 for supplying an adhesive to the portion was formed. In FIG. 1, the adhesive supply groove 8 is formed so as to extend linearly from the tip of the optical fiber housing groove 3 to both sides.

  Even when the adhesive supply groove 8 is formed, if the viscosity of the adhesive is too high, a sufficient amount of adhesive cannot be supplied to the tip of the optical fiber housing groove 3 when the adhesive is cured. Therefore, it is desirable to use an adhesive having a viscosity as low as possible, specifically, a viscosity of 2000 mPa · s or less.

  Further, in the optical module 1 according to the present embodiment, adhesive recovery grooves 9 for recovering the adhesive pushed out when the pressing plate 6 is provided are formed on both sides of the optical fiber housing groove 3. . In FIG. 1, two adhesive collecting grooves 9 are formed in a straight line so as to sandwich the optical fiber housing groove 3 and parallel to the optical fiber housing groove 3. By forming the adhesive collecting groove 9, it is possible to prevent the adhesive from leaking to the outside when the pressing plate 6 is provided. In particular, when the optical fiber 2 is mounted in the small optical module 1. It becomes possible to improve the property.

  In the present embodiment, the adhesive collecting groove 9 and the adhesive supplying groove 8 are connected. As a result, the adhesive pushed out when the presser plate 6 is provided is supplied to the tip of the optical fiber housing groove 3 via the adhesive recovery groove 9 and the adhesive supply groove 8. It is possible to more effectively suppress the occurrence of peeling of the adhesive at the tip of the housing groove 3.

  By forming the adhesive supply groove 8 and the adhesive recovery groove 9, the strength (mechanical strength) of the optical waveguide 4 is lowered. Therefore, in order to prevent the strength of the optical waveguide 4 from being excessively reduced, when the optical waveguide 4 is formed in a rectangular shape having a side of 3 mm or less in plan view, the optical fiber housing groove 3 and the adhesive supply groove 8. It is desirable that the area of the entire groove including the adhesive collecting groove 9 in plan view is about 1/3 to 2/3 of the area of the entire optical waveguide 4 in plan view.

  The shape of the entire groove including the optical fiber housing groove 3, the adhesive supply groove 8, and the adhesive recovery groove 9 is relative to the center of the optical waveguide 4 in the width direction (left-right direction in FIG. 1A). A line-symmetric shape is desirable. This is to reduce the effect of thermal expansion and contraction when there is a large temperature change such as a heat shock, and to suppress distortion generated in the optical waveguide 4.

  As shown in FIG. 2, it is possible to accommodate the dummy optical fiber 21 for reinforcing the optical waveguide 4 in the adhesive collecting groove 9. The dummy optical fiber 21 may be the same as or different from the optical fiber 2. Of course, a resin rod-like member or the like can be provided in place of the dummy optical fiber 21. By providing the dummy optical fiber 21, not only the optical waveguide 4 can be reinforced, but also expansion and contraction due to temperature change can be suppressed, and distortion generated in the optical waveguide 4 due to temperature change can be suppressed.

  Further, in the present embodiment, the adhesive supply groove 8 and the adhesive recovery groove 9 are formed in a straight line, but the present invention is not limited to this. For example, as shown in FIG. The groove 8 and the adhesive collecting groove 9 may be curved.

  When the optical fiber 2 is mounted on the optical waveguide 4 in the optical module 1, first, the optical fiber 2 is accommodated in the optical fiber accommodation groove 3, and the optical fiber accommodation groove 3 is filled with an adhesive. At this time, the tip of the optical fiber housing groove 3 is also filled with an adhesive.

  Thereafter, the pressing plate 6 is pressed so as to close the optical fiber housing groove 3. The adhesive pushed out at this time is collected in the adhesive collecting groove 9 and supplied to the distal end portion of the optical fiber housing groove 3 through the adhesive supplying groove 8 when the adhesive is cured.

  The adhesive is not cured and the optical fiber 2 is not fixed when the pressing plate 6 is pressed, but the optical fiber 2 is only in the space in the optical fiber housing groove 3 closed by the pressing plate 6. Can only move. In the present embodiment, the distance that the optical fiber 2 is allowed to move in the radial direction is 20 μm or less at this time, so that the optical loss is within the allowable range no matter how much the optical fiber 2 moves within this range. No problem.

  Thereafter, when the adhesive is cured by irradiating the adhesive with ultraviolet rays, the optical fiber 2 and the pressing plate 6 are fixed to the optical waveguide 4, and the mounting operation of the optical fiber 2 on the optical waveguide 4 is completed.

  As described above, in the optical module 1 according to the present embodiment, the optical fiber accommodation groove 3 accommodates the entire tip of the optical fiber 2 so that the optical fiber 2 does not protrude from the surface of the optical waveguide 4. When the distal end portion of the optical fiber 2 is accommodated in the optical fiber accommodation groove 3 and the opening of the optical fiber accommodation groove 3 is closed with the pressing plate 6, the distal end portion of the optical fiber 2 moves in the radial direction. It is formed so that the allowable distance is 20 μm or less.

  By forming the optical fiber housing groove 3 deeply so as to accommodate the entire tip of the optical fiber 2, the pressing plate 6 does not interfere with the optical fiber 2, and the tilting and misalignment of the pressing plate 6, And it becomes possible to suppress the position shift of the optical fiber 2.

  Further, when the opening of the optical fiber housing groove 3 is closed with the pressing plate 6, the distance that the tip of the optical fiber 2 is allowed to move in the radial direction is set to 20 μm or less, whereby the core of the optical fiber 2 It is possible to reliably suppress the positional deviation between the optical waveguide 4 and the core 4a of the optical waveguide 4. Further, if the tip of the optical fiber 2 is accommodated in the optical fiber accommodation groove 3 and closed with the holding plate 6, the alignment of the core of the optical fiber 2 and the core 4a of the optical waveguide 4 is naturally performed. It becomes possible to improve workability at the time of mounting the fiber 2.

  That is, according to the optical module 1, it is possible to suppress the displacement of the pressing plate 6 and the optical fiber 2, and to facilitate the mounting operation of the optical fiber 2.

  Next, another embodiment of the present invention will be described.

  The optical module 41 shown in FIG. 4 forms an adhesive filling portion 3a in which the optical fiber housing groove 3 is expanded in the width direction at a position spaced from the tip of the optical fiber housing groove 3, and is bonded to the adhesive filling portion 3a. An agent is filled so that the tip of the optical fiber housing groove 3 is not filled with an adhesive.

  In the optical module 1 of FIG. 1, since the tip of the optical fiber housing groove 3 is filled with an adhesive, the adhesive supply groove 8 is formed so that peeling does not occur when the adhesive is cured. In order to avoid the influence of peeling at the time of hardening of the adhesive, the tip of the optical fiber housing groove 3 is not filled with the adhesive in the first place.

  In the optical module 41, since the tip of the optical fiber housing groove 3 is not filled with adhesive, the tip surface of the optical fiber 2 is processed into a flat surface without unevenness by laser processing or mechanical processing, and the optical fiber 2. It is desirable to suppress light loss due to irregular reflection or the like at the unevenness of the tip surface of the glass.

  If the adhesive is filled only in the adhesive filling portion 3a and the optical fiber housing groove 3 around the adhesive filling portion 3a, there is a possibility that the fixing of the pressing plate 6 to the optical waveguide 4 may be insufficient. A linear auxiliary adhesive filling groove 42 extending in the width direction is formed on the side opposite to the optical fiber housing groove 3, and the auxiliary adhesive filling groove 42 is also filled with an adhesive so that the holding plate 6 is sufficiently attached. It is configured to be fixed.

  In order to prevent the adhesive from flowing into the tip of the optical fiber housing groove 3 when the adhesive is filled, an adhesive having a viscosity as high as possible, specifically, one having a viscosity of 1000 mPa · s or more should be used. Is desirable.

  Further, in order to prevent the adhesive from reaching the tip of the optical fiber housing groove 3 when the pressing plate 6 is pressed, for example, as shown in FIG. An adhesive relief groove 51 may be connected and formed between the adhesive filling portion 3a and the adhesive filling portion 3a.

  Moreover, as shown in FIG.5 (b), it is also possible to connect and form the adhesive escape groove | channel 52 to the adhesive agent filling part 3a. The width of the adhesive relief groove 52 is narrower than the width of the optical fiber housing groove 3. Since the adhesive easily flows into the narrow adhesive escape groove 52, the adhesive can be prevented from flowing into the tip portion of the optical fiber housing groove 3. In FIG.5 (b), although the adhesive relief groove | channel 52 is formed so that it may extend back (on the opposite side to the core 4a) from the adhesive filling part 3a, it is not restricted to this, For example, from the adhesive filling part 3a It is also possible to form the adhesive escape groove 52 so as to extend on both sides.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Optical module 2 Optical fiber 3 Optical fiber accommodation groove 4 Optical waveguide 4a Core 5 Optical element 6 Holding plate 7 Substrate 8 Adhesive supply groove 9 Adhesive collection groove

Claims (11)

Optical fiber,
An optical waveguide formed with an optical fiber housing groove for housing the tip of the optical fiber;
An adhesive that fixes the optical fiber to the optical fiber accommodation groove by being filled and cured in the optical fiber accommodation groove containing the optical fiber, and
A pressing plate that is provided so as to cover an upper portion of the optical fiber accommodation groove that contains the optical fiber and is filled with the adhesive, and suppresses the positional deviation of the optical fiber;
With
The optical fiber core and the optical waveguide core are optically matched by abutting the front end surface of the optical fiber accommodated in the optical fiber accommodation groove with the inner wall of the optical fiber accommodation groove where the core is exposed. An optical module configured to be coupled together,
The optical fiber receiving groove is
Formed so as to accommodate the entire tip of the optical fiber so that the optical fiber does not protrude from the surface of the optical waveguide,
In addition, when the tip of the optical fiber is housed in the optical fiber housing groove and the opening of the optical fiber housing groove is closed with the pressing plate, the tip of the optical fiber is allowed to move in the radial direction. The optical module is formed so that the distance to be measured is 20 μm or less. The optical fiber receiving groove is
Formed in a rectangular shape in cross-sectional view,
The optical module according to claim 1, wherein the optical module is formed such that a difference between the width and depth and the diameter of the tip of the optical fiber is 0 μm or more and 20 μm or less. The optical fiber is housed in the optical fiber housing groove with its coating at the tip,
The optical module according to claim 1, wherein a thickness of the coating is less than 15 μm. The adhesive is filled at the tip of the optical fiber housing groove,
The optical waveguide is connected to the distal end portion of the optical fiber housing groove, and the adhesive is disposed at the distal end portion of the optical fiber housing groove so that the adhesive does not peel off due to curing shrinkage when the adhesive is cured. An optical module according to any one of claims 1 to 3, wherein an adhesive supply groove for supplying the adhesive is formed. On both sides of the optical fiber housing groove, an adhesive collecting groove for collecting the adhesive pushed out when the pressing plate is provided is formed,
The optical module according to claim 4, wherein the adhesive collecting groove and the adhesive supplying groove are connected. The optical module according to claim 5, wherein a dummy optical fiber for reinforcing the optical waveguide is accommodated in the adhesive collecting groove. The optical module according to claim 4, wherein the adhesive has a viscosity of 2000 mPa · s or less. Forming an adhesive filling portion in which the optical fiber accommodation groove is expanded in the width direction at a position spaced from the tip of the optical fiber accommodation groove, filling the adhesive filling portion with the adhesive, and the optical fiber accommodation groove; The optical module according to any one of claims 1 to 3, wherein an adhesive is not filled in the tip of the optical module. The adhesive pushed out when the pressing plate is provided between the tip of the optical fiber housing groove and the adhesive filling portion or at the adhesive filling portion does not reach the tip of the optical fiber housing groove. The optical module according to claim 8, further comprising an adhesive relief groove connected to release the adhesive. The optical module according to claim 9, wherein a width of the adhesive relief groove is narrower than a width of the optical fiber housing groove. The optical module according to claim 8, wherein the adhesive has a viscosity of 1000 mPa · s or more.