JP2014191055A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device having an optical waveguide hardly fractured even if bent.SOLUTION: An optical device comprises: an optical waveguide 1 in which a lower clad layer 12, a core pattern 13, and an upper clad layer 14 are laminated in this order on a substrate 11; a connector 2 having an optical waveguide insertion port 24 into which one end portion of the optical waveguide is inserted; and a cover plate 3 provided on the optical waveguide on the side of the upper clad layer, over the inside and the outside of the connector, making the optical waveguide insertion port 24 function as a boundary between the inside of the connector and the outside of the connector.

Description

  The present invention relates to an optical device using an optical waveguide.

  With the increase in information capacity, development of an optical interconnection technology that uses optical signals not only for communication fields such as trunk lines and access systems but also for information processing in routers and servers is underway. In particular, as an optical transmission path for using light for short-distance signal transmission between boards in a router and a server device, the degree of freedom of wiring is higher than that of an optical fiber and the density can be increased. It is desirable to use an optical waveguide. Among them, an optical waveguide using a polymer material excellent in processability and economy is promising.

For connection between the optical waveguide and the board, for example, a PMT connector (see, for example, Patent Document 1) is attached to the end of the optical waveguide, and another optical waveguide and an optical fiber are attached to the connector and guide pins. Can be performed by positioning.
As a method of connecting the optical waveguide to such a general-purpose PMT connector, first, the optical waveguide is fitted into the optical waveguide fitting portion (optical waveguide fixing portion) formed in the PMT connector body, and the alignment is performed. And fix with an adhesive. Next, the PMT lid is fixed to the upper surface of the optical waveguide, and the optical waveguide is protected by the PMT boot (for example, see Non-Patent Document 1).

JP 2006-011210 A

JPCA Standard “Detailed Specification of PMT Optical Connector” JPCA-PE03-01-07S- (2006) Japan Electronic Circuits Association May 2006

  However, if the optical waveguide is bent with the optical waveguide attached to a rigid connector such as a PMT connector, the optical waveguide is near the portion where the optical waveguide is exposed from the connector (the PMT boot end opposite to the end surface on the PMT connector side). However, there was a problem that it was easy to break.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an optical device having an optical waveguide in which the optical waveguide is not easily broken even when bent.

As a result of intensive studies, the present inventors have obtained a coated optical waveguide having a coating plate that sandwiches the boundary between the inside of the connector and the outside of the connector on a part of the optical waveguide opposite to the substrate of the optical waveguide. The present inventors have found that the above-described problems can be solved by using an optical device having the present invention, and have completed the present invention.
That is, the present invention
(1) An optical waveguide in which a lower clad layer, a core pattern, and an upper clad layer are sequentially laminated on a substrate, a connector having an optical waveguide insertion slot into which one end of the optical waveguide is inserted, and the optical waveguide insertion slot An optical device comprising a boundary between the inside of the connector and the outside of the connector, and a cover plate provided across the inside of the connector and the outside of the connector on the optical waveguide on the upper clad layer side,
(2) The optical device according to (1), wherein at least a part of both ends of the outer shape in the direction perpendicular to the core pattern of the optical waveguide in the connector is not covered with the covering plate,
(3) The optical device according to (1) or (2), wherein the width of the covering plate at the boundary is narrower than the width of the optical waveguide at the boundary,
(4) The length of the said coating | coated board in the said connector is 0.05 mm-10 mm, The optical device in any one of (1)-(3),
(5) The optical device according to any one of (1) to (4), wherein the length of the cover plate outside the connector is longer than the length of the cover plate in the connector.
(6) The optical device according to any one of (1) to (5), wherein an optical path conversion mirror is provided in the optical waveguide outside the connector.
(7) The optical device according to (6), wherein the covering plate is provided up to the optical waveguide on the optical path conversion mirror,
(8) The optical device according to any one of (1) to (7), wherein the optical waveguide has flexibility.
(9) The optical device according to any one of (1) to (8), wherein the covering plate has flexibility.
(10) The optical device according to any one of (1) to (9), wherein the cover plate is bonded to the optical waveguide via an adhesive layer.
(11) The optical device according to any one of (1) to (10), wherein the covering plate has polyimide as a main component,
(12) The optical device according to any one of (1) to (11), wherein the substrate is transparent,
(13) The optical device according to any one of (1) to (12), wherein the substrate has polyimide as a main component.
(14) The optical device according to any one of (1) to (13), wherein the thickness of the cover plate is equal to or greater than the thickness of the substrate.
Is to provide.

  According to the present invention, it is possible to provide an optical device having an optical waveguide in which the optical waveguide is hardly broken even when it is bent.

It is sectional drawing which shows the one aspect | mode of the optical device which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the one aspect | mode of the optical device which concerns on the 1st Embodiment of this invention. It is a perspective view showing one mode of a connector main part concerning a 1st embodiment of the present invention. It is a perspective view which shows the one aspect | mode of the connector cover which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the one aspect | mode of the connector boot which concerns on the 1st Embodiment of this invention. It is a top view which shows the shape of the coating plate which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the one aspect | mode of the optical device which concerns on the 2nd Embodiment of this invention.

(First embodiment)
As shown in FIGS. 1 and 2, the optical device according to the first embodiment of the present invention includes an optical waveguide 1 and a connector 2 having an optical waveguide insertion port 24 into which one end of the optical waveguide 1 is inserted. The optical waveguide insertion port 24 is defined as a boundary L between the connector inner A and the connector outer B, and the cover plate 3 provided across the connector inner A and the connector outer B is provided on the optical waveguide 1 on the upper clad layer 14 side. .
Below, each member used for the optical device which concerns on the 1st Embodiment of this invention is demonstrated in detail.

[Optical waveguide]
The optical waveguide 1 is formed by sequentially laminating a lower clad layer 12, a core pattern 13, and an upper clad layer 14 on a substrate 11. In the optical waveguide 1, the cover plate 3 is further disposed on the upper clad layer 14 side. By providing the substrate 11, the optical waveguide 1 can suppress breakage due to bending of the optical waveguide 1 on the lower clad layer 12 side, and can suppress breakage due to bending on the upper clad layer 14 side by providing the cover plate 3.
From the viewpoint of suppressing the overall thickness of the optical waveguide 1 while securing the thickness of the core pattern 13 in the optical waveguide fixing portion 25 in the connector 2, a covering plate is provided at a place where the optical waveguide 1 is fitted in the optical waveguide fixing portion 25. 3 is preferably not arranged. When the optical waveguide fixing portion 25 is narrow and the thickness of the optical waveguide 1 is limited, if the cover plate 3 is not provided on the optical waveguide 1 in the optical waveguide fixing portion 25, the space for forming the core pattern 13 increases and the lower cladding is formed. Since it is not necessary to form the layer 12 and the upper cladding layer 14 thinly, the thickness control of the layer and the light propagation characteristics are favorably affected. Even if the coating plate 3 is not provided in the optical waveguide fixing portion 25, the optical waveguide 1 is provided with the substrate 11, so that the strength is maintained.

<Board>
The substrate 11 has an effect of suppressing breakage of the optical waveguide 1 from the lower clad layer 12 side, and an effect of suppressing breakage of the optical waveguide 1 when an optical path conversion mirror is formed on the optical waveguide 1 using a dicing saw or the like. There is. A flexible material having flexibility and toughness is preferably used as the substrate 11 because flexibility can be imparted to the optical waveguide 1. As the substrate 11, from the above viewpoint, for example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polyamide, polycarbonate, polyphenylene ether, polyether sulfide, polyarylate, liquid crystal polymer, polysulfone, polysulfone Preferred examples include ether sulfone, polyether ether ketone, polyether imide, polyamide imide, polyimide, and a flexible electric wiring board on which electric wiring is formed. More preferable substrate 11 includes polyimide, a laminate mainly composed of polyimide, and the like from the viewpoint of dimensional stability, heat resistance, and high bending.
The substrate 11 is preferably made of a material that is transparent to the wavelength of the optical signal transmitted through the optical waveguide 1 because the optical signal can pass through the substrate 11. Further, it is preferable that the substrate 11 is transparent with respect to the wavelength of the inspection light used for the inspection of the core pattern 13 because the core pattern 13 is visible through the substrate 11. From the above viewpoint, it is preferably transparent to at least one of ultraviolet light, visible light, and infrared light. In addition, as the board | substrate 11, if it is transparent with the coating plate 3 with respect to the wavelength of the test | inspection light used for a test | inspection, since the test | inspection using transmitted light is possible, it is more preferable.

  The thickness of the substrate 11 is not particularly limited, but if it is 5 μm or more, there is an advantage that it is easy to obtain strength, and if it is 37.5 μm or less, there is an advantage that a low-profile optical waveguide 1 can be obtained. From the above viewpoint, the thickness of the substrate 11 is preferably in the range of 5 to 37.5 μm, and more preferably in the range of 10 to 25 μm.

<Lower cladding layer and upper cladding layer>
The lower clad layer 12 and the upper clad layer 14 are not particularly limited as long as they have a lower refractive index than the core pattern 13 and are cured by heat and light, and a thermosetting resin or a photosensitive resin is preferably used. Can do. The clad layer forming resins for forming the lower clad layer 12 and the upper clad layer 14 may contain the same or different components, and may have the same or different refractive indexes.

  The thickness of the lower clad layer 12 and the upper clad layer 14 is not particularly limited, but is preferably in the range of 5 to 500 μm. If the thickness after pattern formation is 5 μm or more, the cladding thickness necessary for light confinement can be secured, and if it is 500 μm or less, the low-profile optical waveguide 1 can be obtained. From the above viewpoint, the thicknesses of the lower cladding layer 12 and the upper cladding layer 14 are more preferably in the range of 10 to 100 μm.

<Core pattern>
The core pattern 13 is not particularly limited as long as it has a higher refractive index than the lower cladding layer 12 and the upper cladding layer 14 and is transparent to the extent that the optical signal used does not affect the transmission of the optical signal. It is preferable to use what can be converted. As an example of the patterning method, a resin layer for forming the core pattern 13 can be formed on the lower clad layer 12 and exposed and developed. From the above viewpoint, the resin forming the core pattern 13 is preferably a photosensitive resin composition.

  The thickness of the core pattern 13 is not particularly limited. However, when the thickness after the pattern formation is 10 μm or more, the alignment tolerance can be increased in coupling with the light emitting / receiving element or the optical fiber after the optical waveguide is formed. In the case of 100 μm or less, there is an advantage that the coupling efficiency is improved in coupling with the light emitting / receiving element or the optical fiber after the optical waveguide is formed. From the above viewpoint, the thickness of the core pattern 13 is preferably in the range of 10 to 100 μm, and more preferably in the range of 30 to 90 μm.

[connector]
The connector 2 may be a connector having an optical waveguide fixing portion 25 that fixes the upper surface, the lower surface, and the side surface of the optical waveguide 1 and an optical waveguide protection portion 26 having a gap thicker than the thickness of the optical waveguide 1. A connector can be used. A PMT connector as an application of the optical waveguide 1 is most preferable. When the connector 2 is a PMT connector, it comprises a connector main body 21, a connector lid 22, and a connector boot 23 as shown in FIGS.
The gap in the thickness direction of the optical waveguide 1 of the optical waveguide protection part 26 is larger than the gap of the optical waveguide fixing part 25 from the viewpoint of inserting at least a part of the optical waveguide 1 with the cover plate 3 into the optical waveguide protection part 26. The gap may be a thick gap on the upper clad layer 14 side. As shown in FIG. 1, there may be a thick gap on both the upper cladding layer 14 side and the lower cladding layer 12 side. When a PMT connector is used as the connector 2, an optical device can be obtained by fixing the optical waveguide 1 to the connector main body 21, the connector lid 22, and the connector boot 23.

[Coating board]
As shown in FIGS. 1 and 2, the covering plate 3 only needs to be provided on the optical waveguide 1 on the upper clad layer 14 side across the boundary L between the connector inner A and the connector outer B. It is arranged so as to be partially inserted into the mouth 24. The covering plate 3 should just be provided in at least one part of the boundary L of the connector inner A and the connector outer B. FIG. The length of the cover plate 3 inserted into the connector A may be a length that allows the cover plate 3 to remain outside the connector B when the optical waveguide 1 is bent, and is within the length of the optical waveguide protector 26. If it is, there will be no limitation in particular, However, It is good that it is 0.05 mm-10 mm, It is further better if it is 0.2 mm-5 mm, It is still more preferable that it is 0.5 mm-4 mm.
The length of the cover plate 3 outside the connector B is the length of the cover plate 3 arranged in the connector A from the viewpoint that the optical waveguide 1 can be prevented from being bent at the end point of the cover plate 3 outside the connector B. It is preferable that the length is longer. The length of the cover plate 3 outside the connector B is not particularly limited, but may be longer than the length of the cover plate 3 inserted into the connector A, and is preferably 0.1 to 400 mm.

In addition, as shown in FIGS. 6A to 6C, for example, the covering plate 3 has at least a part of both ends of the outer shape perpendicular to the core pattern 13 of the optical waveguide 1 in the connector A. 3 is preferably not covered. The cover plate 3 shown in FIG. 6A is tapered at the boundary L between the connector inner A and the connector outer B. The cover plate 3 shown in FIG. 6B has a curved shape at the boundary L between the connector inner A and the connector outer B. The cover plate 3 shown in FIG. 6C has a linear shape orthogonal to the boundary L between the connector inner A and the connector outer B.
By not covering at least a part of both ends 3e of the outer shape in the direction perpendicular to the core pattern 13 of the optical waveguide 1 with the covering plate 3, it is possible to suppress the occurrence of burrs during the outer shape processing. This is preferable because there is an advantage that it can be inserted satisfactorily. From the above viewpoint, it is preferable that not all the both ends 3 e of the outer shape in the direction perpendicular to the core pattern 13 of the optical waveguide 1 in the connector A are covered with the covering plate 3.

  6A to 6C, the width of the cover plate 3 at the boundary L is preferably narrower than the width of the optical waveguide 1 at the boundary L. By making the width of the cover plate 3 at the boundary L smaller than the width of the optical waveguide 1 at the boundary L, even if burrs are generated during the outer shape processing of the cover plate 3 on the boundary L, the burrs are outside the connector B. When the optical waveguide 1 is inserted into the connector 2, it is preferable because there is an advantage that it can be inserted satisfactorily without interference of burrs.

It is preferable to use a material having flexibility and toughness as the covering plate 3 because flexibility can be imparted to the optical waveguide 1. As the covering plate 3, from the above viewpoint, for example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene, polypropylene, polyamide, polycarbonate, polyphenylene ether, polyether sulfide, polyarylate, liquid crystal polymer, polysulfone, Suitable examples include polyethersulfone, polyetheretherketone, polyetherimide, polyamideimide, polyimide, and flexible electric wiring boards on which electric wiring is formed. More preferable cover plate 3 includes polyimide, a laminate mainly composed of polyimide, and the like from the viewpoint of dimensional stability, heat resistance, and high bending.
The covering plate 3 is preferably transparent to the wavelength of the inspection light used for the inspection of the core pattern 13 because the visibility of the core pattern 13 through the covering plate 3 can be obtained. From the above viewpoint, it is preferably transparent to at least one of ultraviolet light, visible light, and infrared light.

  The thickness of the cover plate 3 is not particularly limited as long as it is a thickness that can enter the optical waveguide protection part 26, but is 10 to 75 μm from the viewpoint of ensuring flexibility and obtaining the low-profile optical waveguide 1. Preferably, it is 10-50 micrometers. Moreover, since the curvature of the optical waveguide 1 can be reduced by making the thickness of the coating | coated board 3 the same as the board | substrate 11 or thicker than the board | substrate 11, it is more preferable.

  When there is no adhesive force between the upper clad layer 14 and the cover plate 3, it is preferable to bond the cover plate 3 through the adhesive layer 31.

(Second Embodiment)
As shown in FIG. 7, the optical device according to the second embodiment of the present invention has an optical path conversion mirror 15 in the optical waveguide 1 outside the connector B, as compared with the optical device shown in the first embodiment. Is different. Regarding the optical device according to the second embodiment, the description of the portions that are substantially the same as those of the optical device according to the first embodiment will be omitted because they are redundant descriptions.

<Optical path conversion mirror>
The optical path changing mirror 15 may be a 45 ° inclined surface having a function of changing the optical path of the optical signal propagated through the core pattern 13 in a direction substantially perpendicular to the substrate 11 and the upper clad layer 14, and is an air reflecting mirror. Alternatively, it may be a metal reflecting mirror in which a reflective metal layer is formed in the notch.
As a specific example, the optical path conversion mirror 15 can be formed by cutting and removing the core pattern 13 and the upper clad layer 14 using a dicing saw or the like from the upper clad layer 14 side.
It is preferable to provide a cover plate 3 for reinforcing the optical path conversion mirror on the optical path conversion mirror 15 (on the upper clad layer 14 side). When the cover plate 3 on the optical path conversion mirror 15 and the cover plate 3 sandwiching the boundary L between the connector inner A and the connector outer B are integrated, the light from the connector end (main body side) to the optical path conversion mirror 15 is transmitted. This is more preferable because breakage due to bending of the waveguide 1 can be suppressed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded.

[Example 1]
<Formation of lower cladding layer>
A 17.5 μm-thick lower cladding layer 12 (refractive index: 1.496) is laminated on a polyimide film (polyimide; Kapton EN (manufactured by Toray DuPont), thickness: 12.5 μm) as a substrate 11, and 170 ° C. for 1 hour. Was heat cured.

<Formation of core pattern>
Next, a resin film for forming a core layer (refractive index of 1.555) having a thickness of 50 μm is laminated on the lower clad layer 12 formed as described above, and a core pattern 13 (pattern width: 50 μm, number of pieces: 12, pieces, pattern pitch; 250 μm, length: 120 mm) was formed by photolithography by simultaneous exposure and development, and thermoset under the same conditions as the lower clad layer 12.

<Formation of upper clad layer>
The core pattern (core pattern for optical signal transmission, dummy core pattern) 13 is embedded with the resin film for forming the upper clad layer from the surface on which the core pattern 13 is formed, and the upper clad layer 14 (refractive index: 1.496) is embedded. The optical waveguide 1 having a thickness of 100 μm was formed.

<Formation of optical path conversion mirror>
One optical path conversion mirror 15 having a 45 ° inclined surface facing the core pattern 13 and the upper clad layer 14 is provided from the upper clad layer 14 formation surface side using a dicing saw (DAC552, manufactured by Disco Corporation). (15 mm from the end of one core pattern 13).

<Formation of coated plate>
A polyimide film (Kapton EN (manufactured by Toray Du Pont), thickness 12.5 μm) having an adhesive layer (thickness 15 μm) 31 made of a thermosetting adhesive on the surface on which the upper clad layer 14 is formed is placed on one side of the core pattern 13. It is laminated and heat-cured in the range of 98 mm from the end (near the optical path conversion mirror 15) (position at the product width end during outer shape processing) to 102 mm (position at the center of the product width at outer shape processing), and on the optical path conversion mirror 15 A cover plate 3 was formed.

<Outline processing>
Product width: 3.0 mm, product length: 100 mm (10 mm from the end of the core pattern, respectively) using a dicing saw (DAC552, manufactured by DISCO Corporation) from the surface of the obtained optical waveguide 1 where the upper clad layer 14 is formed ).
The cover plate 3 on the optical waveguide 1 is formed with a length of 92 mm at the center of the product width. The covering plate 3 on the optical waveguide 1 is formed with a length of 88 mm at both ends of the product width.

The obtained optical waveguide 1 is mounted on an optical waveguide fixing portion 25 having a connector 2 (manufactured by Hakusan Seisakusho, trade name: PMT connector, optical waveguide fitting portion shape (width 3.0 mm, height 100 μm)) to protect the optical waveguide. An optical device in which the 3 mm-coated plate 3 was inserted into the portion 26 was produced.
The connector main body 21 is held, and the optical path conversion mirror 15 side of the optical waveguide 1 is bent 90 ° with the cover plate 3 inward (minimum bending radius 1.5 mm). Propagated. Next, when the cover plate 3 was bent outward by 90 ° (minimum bend radius 1.5 mm), the optical waveguide 1 was not broken and the optical signal propagated well.
The warp of the optical waveguide 1 was also good, and the core pattern 13 could be visually confirmed satisfactorily by inspection with white transmitted light.

[Example 2]
In Example 1, an optical device was produced in the same manner except that the thickness of the cover plate 3 was changed to 25 μm. As in the first embodiment, the connector main body 21 is held, and the optical path conversion mirror 15 side of the optical waveguide 1 is bent 90 ° with the cover plate 3 inward (minimum bending radius 1.5 mm). The optical signal propagated well. Next, when the cover plate 3 was bent outward by 90 ° (minimum bend radius 1.5 mm), the optical waveguide 1 was not broken and the optical signal propagated well.
The warp of the optical waveguide 1 was also better than that of Example 1, and the core pattern 13 could be visually recognized satisfactorily by inspection with white transmitted light.

[Comparative Example 1]
In Example 1, the optical device was formed without forming the covering plate 3. The connector main body 21 is held in the same manner as in Example 1, and the optical waveguide 1 is bent by 90 ° with the optical path conversion mirror 15 side of the optical waveguide 1 facing the upper cladding layer 14 side (minimum bending radius 1.5 mm). The optical signal propagated well without breaking. Next, the optical waveguide 1 was broken near the boundary L inside and outside the connector when bent by 90 ° with the upper clad layer 14 side outward (minimum bending radius 1.5 mm).
The warp of the optical waveguide 1 was also larger than that of Example 1.

[Comparative Example 2]
In Example 1, the optical waveguide 1 having a thickness of 100 μm composed of the lower clad layer 12, the core pattern 13, and the upper clad layer 14 is formed without providing the substrate 11, and the covering plate is formed on the upper clad layer 14 side as in the first example. 3 was provided to produce an optical device. Similar to the first embodiment, the connector main body 21 is held, and the optical path conversion mirror 15 side of the optical waveguide 1 is bent 90 ° with the cover plate 3 inside, and light is transmitted near the boundary L between the connector inner A and the connector outer B. Waveguide 1 was broken. Next, when the cover plate 3 was bent outward by 90 ° (minimum bend radius 1.5 mm), the optical waveguide 1 was not broken and the optical signal propagated well.

[Comparative Example 3]
In Example 1, an optical device was formed by the same method except that the length of the cover plate 3 on the optical waveguide 1 at the center of the product width was 88 mm. There is no covering plate 3 in the optical waveguide protection part 26, and there is an end of the covering plate 3 at a point B outside the connector 1 mm outside the boundary L. The connector main body 21 is held in the same manner as in Example 1, and the optical waveguide 1 is bent by 90 ° with the optical path conversion mirror 15 side of the optical waveguide 1 facing the upper cladding layer 14 side (minimum bending radius 1.5 mm). The optical signal propagated well without breaking. Next, when the upper clad layer 14 side was bent 90 ° (minimum bending radius 1.5 mm), the optical waveguide 1 was broken near the boundary L between the connector inner A and the connector outer B.

  The optical device of the present invention is an optical device having an optical waveguide in which the optical waveguide is not easily broken even when it is bent. Therefore, the optical device can be applied to a wide range of fields such as various optical devices and optical interconnections.

DESCRIPTION OF SYMBOLS 1 ... Optical waveguide 11 ... Board | substrate 12 ... Lower clad layer 13 ... Core pattern 14 ... Upper clad layer 15 ... Optical path conversion mirror 2 ... Connector 21 ... Connector main body 22 ... Connector lid 23 ... Connector boot 25 ... Optical waveguide fixing | fixed part 26 ... Light Waveguide protection part 3 ... Cover plate 31 ... Adhesive layer L ... Boundary A between connector and outside A ... Inside connector B ... Outside connector

Claims (14)

An optical waveguide in which a lower clad layer, a core pattern, and an upper clad layer are sequentially laminated on a substrate;
A connector having an optical waveguide insertion port into which one end of the optical waveguide is inserted;
An optical device comprising the optical waveguide insertion port as a boundary between the inside of the connector and the outside of the connector, and a cover plate provided on the optical waveguide on the upper clad layer side so as to extend inside the connector and outside the connector.   The optical device according to claim 1, wherein at least a part of both ends of the outer shape in a direction perpendicular to the core pattern of the optical waveguide in the connector is not covered with the covering plate.   The optical device according to claim 1, wherein a width of the covering plate at the boundary is narrower than a width of the optical waveguide at the boundary.   The optical device according to claim 1, wherein a length of the covering plate in the connector is 0.05 mm to 10 mm.   The optical device according to claim 1, wherein a length of the cover plate outside the connector is longer than a length of the cover plate in the connector.   The optical device according to claim 1, wherein an optical path conversion mirror is provided in the optical waveguide outside the connector.   The optical device according to claim 6, wherein the covering plate is provided up to the optical waveguide on the optical path conversion mirror.   The optical device according to claim 1, wherein the optical waveguide has flexibility.   The optical device according to claim 1, wherein the covering plate has flexibility.   The optical device according to claim 1, wherein the cover plate is bonded to the optical waveguide via an adhesive layer.   The optical device according to claim 1, wherein the covering plate contains polyimide as a main component.   The optical device according to claim 1, wherein the substrate is transparent.   The optical device according to claim 1, wherein the substrate is mainly composed of polyimide.   The optical device according to claim 1, wherein a thickness of the covering plate is equal to or greater than a thickness of the substrate.