Method for connecting optical waveguide and optical waveguide connection device

Abstract

This method for connecting an optical waveguide comprises: adjusting the position of an optical circuit board (1); supplying an adhesive (3) to the vicinity of an optical input part on the optical circuit board; aligning an optical fiber block (2) that holds an optical fiber (2a) with respect to the optical circuit board such that the intensity of light emitted from the optical circuit board becomes maximum; starting curing of the adhesive in a state where the optical fiber block is aligned with respect to the optical circuit board; measuring the cure degree and cure time of the adhesive while the adhesive is being cured; and repeats alignment of the optical fiber block that holds the optical fiber with respect to the optical circuit board such that the intensity of light emitted from the optical circuit board becomes maximum in a state where the cure degree is less than or equal to a certain threshold.

Description

Optical waveguide connection method and optical waveguide connection device

[0001] The present disclosure relates to a method for connecting optical waveguides and an optical waveguide connecting device.

[0002] In recent years, the use of light has been explored in the fields of high-speed communication, large-capacity communication, and sensing. In particular, a technology called "silicon photonics" has attracted attention. This technology forms optical circuits on silicon substrates using a CMOS (Complementary Metal Oxide Semiconductor) process, similar to semiconductor electronic circuits. Optical circuits formed by silicon photonics are micro-sized circuits with optical control functions. Optical input / output units, optical modulators, and the like are formed in the optical circuit. These are connected to each other by micro-optical waveguides on the submicron order. In order to connect external transmitters such as optical fibers to these optical waveguides with high precision, various optical interfaces have been actively developed.

[0003] A typical method for connecting an optical fiber to an optical waveguide on an optical circuit board (i.e., fiber-to-chip connection) is to adhesively fix an end face of an optical input section formed on the optical circuit board to the entire connecting end face of an optical fiber array or optical fiber block that bundles one or more optical fibers.

[0004] When this method is used to fix an optical fiber block to an optical circuit board, it is known that when the adhesive hardens, the relative positions of the optical circuit board and the optical fiber block shift due to the hardening shrinkage of the adhesive, resulting in connection loss.

[0005] Patent Document 1 discloses that by providing a groove along the edge (periphery) of the underside of the ferrule that holds the optical fiber, adhesive that overflows from the underside of the ferrule is absorbed into the groove by capillary action, preventing the adhesive from adhering to the side of the ferrule and suppressing misalignment of the ferrule in the parallel direction due to cure shrinkage.

[0006] Japanese Patent Application Laid-Open No. 2019-144434

[0007] A method for connecting optical waveguides according to one aspect of the present disclosure includes adjusting a position of an optical circuit board; supplying an adhesive near an optical input portion on the optical circuit board; aligning an optical fiber block that holds an optical fiber with respect to the optical circuit board so that the intensity of light emitted from the optical circuit board is maximized; starting to cure the adhesive while the optical fiber block is aligned with the optical circuit board; measuring a degree of cure of the adhesive; measuring an adhesive curing time while the adhesive is curing; and aligning the optical fiber block that holds the optical fiber with respect to the optical circuit board so that the intensity of light emitted from the optical circuit board is maximized by referring to the degree of cure of the adhesive and the adhesive curing time.

[0008] an adhesive curing unit that cures the adhesive while the optical fiber block is aligned with the optical circuit board; an adhesive curing time detection mechanism that detects the curing time of the adhesive when curing the adhesive; a curing degree measurement unit that measures the curing degree of the adhesive; and a control unit that controls the optical fiber alignment mechanism, wherein, under the control of the control unit, the optical fiber alignment mechanism aligns the optical fiber block that holds the optical fiber with the optical circuit board, with reference to the curing degree of the adhesive and the curing time of the adhesive, so that the intensity of the light emitted from the optical circuit board is maximized.

[0009] FIG. 1 is a diagram showing a configuration example of an optical waveguide connection device according to a first embodiment of the present disclosure; FIG. 2 is a control system diagram of an optical waveguide connection device according to a first embodiment of the present disclosure; FIG. 3 is a flowchart showing a method for connecting optical waveguides according to a first embodiment of the present disclosure; FIG. 4 is a diagram for explaining a change in resistance value according to a first embodiment of the present disclosure; FIG. 5 is a diagram showing a configuration example of an optical waveguide connection device according to a second embodiment of the present disclosure; FIG. 6 is a control system diagram of an optical waveguide connection device according to a second embodiment of the present disclosure;

[0010] The conventional technology disclosed in Patent Document 1 requires additional fine processing of the ferrule, which may increase manufacturing costs. Also, when adhesive is supplied, it needs to remain to some extent in the applied area on the optical circuit board, which limits the viscosity of the adhesive and the amount of adhesive that can be applied.

[0011] Non-limiting examples of the present disclosure aim to provide an optical waveguide connection method and an optical waveguide connection device that can suppress misalignment between an optical fiber and an optical input portion of an optical circuit board with a simple configuration regardless of the shape of the adhesive, thereby achieving highly efficient optical coupling.

[0012] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0013] In this specification and drawings, components having substantially the same functions are designated by the same reference numerals, and redundant explanations are omitted. In the following drawings, 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.

[0014] In FIG. 1 and subsequent drawings, 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 perpendicular to each other. The X-axis direction and the Z-axis direction are perpendicular to each other. The Y-axis direction and the Z-axis direction are perpendicular to each other. 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. Also, in FIG. 1 and subsequent drawings, the direction indicated by the arrow in the X-axis direction is the positive X-axis direction, and the direction opposite to this direction is the negative X-axis direction. Also, in FIG. 1 and subsequent drawings, the direction indicated by the arrow in the Y-axis direction is the positive Y-axis direction, and the direction opposite to this direction is the negative Y-axis direction. Also, in FIG. 1 and subsequent drawings, the direction indicated by the arrow in the Z-axis direction is the positive Z-axis direction, and the direction opposite to this direction is the negative Z-axis direction. The Z-axis direction is, for example, the vertical direction or the up-down direction, e.g., equivalent to the thickness direction of the rectangular optical circuit board 1, and the X-axis direction and the Y-axis direction are, for example, the horizontal direction or the left-right direction, e.g., equivalent to the long side direction and the short side direction of the rectangular optical circuit board 1.

[0015] [First Embodiment] <Optical Waveguide Connection Device> First, an optical waveguide connection device D1 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram illustrating a configuration example of the optical waveguide connection device D1 according to the first embodiment of the present disclosure, and FIG. 2 is a control system diagram of the optical waveguide connection device D1 according to the first embodiment of the present disclosure. The optical waveguide connection device D1 is a device that actively aligns and connects an optical circuit board 1 and an optical fiber block 2. Active alignment refers to measuring the light intensity received by a light receiving unit 50 with a measuring device (not shown) and aligning the optical axes of the optical fiber block 2 and the optical circuit board 1 so that the measured light intensity is maximized. In the first embodiment, active alignment is sometimes referred to as "active alignment."

[0016] The optical waveguide connection device D1 includes at least a sample stage 10, an optical fiber alignment mechanism 20, an adhesive supply unit 30, an adhesive curing unit 40, an adhesive curing time detection mechanism 40a, a light receiving unit 50, a resistance measurement unit 60, and a control unit C1. The optical waveguide connection device D1 may further include a sample adjustment mechanism 11 and a light receiving unit alignment mechanism 51.

[0017] The sample stage 10 is provided on the fixed base 100 and is a stage on which the optical circuit board 1 is placed. The sample stage 10 may be of any type as long as it is capable of placing the optical circuit board 1. For example, the sample stage 10 may be provided with suction holes for suctioning the optical circuit board 1, and the optical circuit board 1 may be brought into close contact with the sample stage 10 by applying negative pressure to the suction holes.

[0018] The sample adjustment mechanism 11 is provided between the fixed table 100 and the sample stage 10, and adjusts the position of the optical circuit board 1 on the sample stage 10. Specifically, it adjusts the position of the optical circuit board 1 so that the light emitted from the optical fiber block 2 is approximately coupled with the optical circuit board 1. The sample adjustment mechanism 11 is, for example, a unit in which two linear stages are combined in orthogonal directions. A camera, for example, may be used to adjust the position of the optical circuit board 1.

[0019] The optical fiber aligning mechanism 20 is provided near the sample stage 10 of the fixed base 100. The first movable portion 20e is movable in the X, Y, and Z directions relative to the first fixed portion 20d, thereby actively aligning the optical fiber block 2 held by the first movable portion 20e. The optical fiber aligning mechanism 20 aligns the optical fiber block 2 holding the optical fiber 2a with respect to the optical circuit board 1 while the adhesive 3 is being supplied, so that the intensity of the light received by the light receiving portion 50 is maximized. Specifically, the alignment by the optical fiber aligning mechanism 20 is repeated while the adhesive 3 is being cured by the adhesive curing portion 40, described below, as long as the resistance value measured by the resistance measuring portion 60, described below, is below a threshold value. Here, the optical fiber block 2 is composed of an optical fiber 2a and a holder 2b. The optical fiber 2a is a light-transmitting medium such as a single-mode fiber, a multimode fiber, a quartz fiber, or a plastic fiber. The optical fiber block 2 may be of any type, as long as it holds the optical fiber 2a. The optical fiber aligning mechanism 20 is realized by combining, for example, a linear stage using a linear ball guide or a goniostage. The optical fiber aligning mechanism 20 is provided with a motor 20a and an encoder 20b for each axial direction. Position information of the optical fiber block 2 detected by the encoder 20b is input to the control unit C1. The first movable part 20e of the optical fiber aligning mechanism 20 is configured to be movable in, for example, six mutually different axial directions. The six axial directions include, for example, the X-axis direction, the Y-axis direction, the Z-axis direction, and rotation directions around each of these axes. Note that the movable direction of the optical fiber aligning mechanism 20 may be any one of the six axes. However, if the optical fiber aligning mechanism 20 is movable in six axial directions, fine operation can be achieved in each step of the optical waveguide connection method described below, improving the alignment accuracy and achieving high-quality, highly efficient optical coupling.

[0020] The adhesive supply unit 30 is a unit that supplies adhesive 3 near an optical input unit (not shown) on the optical circuit board 1. The adhesive 3 is made of a photocurable or thermosetting resin such as acrylic resin, epoxy resin, acrylic epoxy resin, or silicone resin. The adhesive supply unit 30 is, for example, a dispenser. The adhesive supply unit 30 may be of any type as long as it can supply the adhesive 3 onto the optical circuit board 1. The amount of adhesive 3 supplied by the adhesive supply unit 30 is, for example, 10 nL to 1000 μL.

[0021] The adhesive curing unit 40 is a unit for fixing the optical fiber block 2 to the optical circuit board 1 by curing the adhesive 3 supplied onto the optical circuit board 1 while the optical fiber block 2 is aligned with respect to the optical circuit board 1. The adhesive curing unit 40 is, for example, an ultraviolet light source, and a heater may also be used depending on the type of adhesive 3. In the optical waveguide connection device D1 disclosed herein, one adhesive curing unit is used as the ultraviolet light source, but multiple adhesive curing units may be provided depending on the connection configuration.

[0022] The adhesive curing time detection mechanism 40a is a count-up timer that detects the time the adhesive 3 is cured by the adhesive curing unit 40. The time information detected by the adhesive curing time detection mechanism 40a is input to the control unit C1.

[0023] The light receiving section 50 is a unit, such as an optical fiber, that receives the light emitted from the optical circuit board 1. Information about the intensity of the light received by the light receiving section 50 is input to the control section C1.

[0024] The light-receiving unit alignment mechanism 51 is provided near the sample stage 10 of the fixed base 100, facing the optical fiber alignment mechanism 20. The second movable portion 51e is a movable stage that moves in the X, Y, and Z directions relative to the second fixed portion 51d to adjust the position of the light-receiving unit 50 held by the second movable portion 51e. The light-receiving unit alignment mechanism 51 is realized, for example, by combining a linear stage using a linear ball guide or a goniostage. The second movable portion 51e of the light-receiving unit alignment mechanism 51 is configured to be movable in, for example, six different axial directions. The six axial directions include, for example, the X-axis direction, the Y-axis direction, the Z-axis direction, and rotational directions about each of these axes. The light-receiving unit alignment mechanism 51 may be movable in any one of the six axes. However, when the light receiving unit alignment mechanism 51 has six movable directions, it is possible to achieve fine movements in each step of the optical waveguide connection method described below, thereby improving alignment accuracy and realizing high-quality and highly efficient optical coupling.

[0025] The resistance measurement unit 60 functions as an example of a curing degree measurement unit that measures the curing degree of the adhesive 3, and is a unit that measures the curing degree of the adhesive 3 by measuring the resistance value applied to the optical fiber block 2 when actively aligning the optical circuit board 1 and the optical fiber block 2. The resistance measurement unit 60 is provided in a holding portion of the optical fiber block 2 and is, for example, a piezoelectric force sensor. Voltage and force information measured by the resistance measurement unit 60 is input to the control unit C1. As the curing of the adhesive 3 progresses, the viscosity increases, and the resistance value measured by the resistance measurement unit 60 increases, and the optical fiber block 2 is unable to follow the operation of the optical fiber alignment mechanism 20. If the mass of the optical fiber block 2 is m, the moving speed of the optical fiber block 2 given by the optical fiber alignment mechanism 20 is v(t), and the viscous resistance of the adhesive 3 is η, the resistance force F applied to the optical fiber block 2 is expressed by the following equation.

[0026]

[0027] Here, when equation (1) is solved for v(t), it is expressed by the following equation.

[0028]

[0029] Therefore, the moving speed of the optical fiber block 2 slows down as the hardening of the adhesive 3 progresses. The alignment operation when the adhesive 3 is hardened by the adhesive hardening unit 40 is repeated if the resistance value measured by the resistance measuring unit 60 is equal to or less than a threshold value. The threshold value of the resistance value is set appropriately depending on the physical properties of the adhesive 3 used and the shape of the optical fiber block 2.

[0030] The control unit C1 is a microcomputer or the like that controls the operation of the components that make up the optical waveguide connection device D1. The control unit C1 controls (active alignment) the optical fiber alignment mechanism 20 so that the intensity of light detected by the light receiving unit 50 is maximized. The control unit C1 also controls the supply amount of adhesive from the adhesive supply unit 30, and the irradiation intensity and irradiation time of the adhesive curing unit 40. The control unit C1 also repeatedly controls (active alignment) the optical fiber alignment mechanism 20 so that the intensity of light detected by the light receiving unit 50 is maximized when the curing time detected by the adhesive curing time detection mechanism 40a has not reached the irradiation time set in the adhesive curing unit 40 and the resistance value measured by the resistance measurement unit 60 has not reached a threshold value.

[0031] <Optical Waveguide Connection Method> Next, a method for connecting optical waveguides using the optical waveguide connection device D1 according to the first embodiment of the present disclosure will be described with reference to Fig. 3 and Fig. 4. Fig. 3 is a flowchart illustrating the optical waveguide connection method according to the first embodiment of the present disclosure, and Fig. 4 is a diagram for explaining changes in resistance value according to the first embodiment of the present disclosure.

[0032] First, the position of the optical circuit-board 1 is adjusted (step S10). In step S10, the optical circuit-board 1 is placed on the sample stage 10, and the position of the optical circuit-board 1 is adjusted by the sample adjustment mechanism 11, for example.

[0033] Next, the adhesive 3 is supplied by the adhesive supply unit 30 to the vicinity of the optical input portion (not shown) on the optical circuit board 1 (step S20). The position where the adhesive 3 is supplied may be appropriately set within a range where the optical circuit board 1 and the optical fiber block 2 can be connected and fixed, and the adhesive 3 may be supplied to a plurality of positions.

[0034] Next, an alignment operation of the optical fiber block 2 with respect to the optical circuit board 1 is performed (step S30). The alignment operation involves moving the optical fiber block 2 to a predetermined position in the XY plane with respect to an optical input portion (not shown) on the optical circuit board 1. The predetermined position is the position of the optical fiber block 2 in the XY plane where the intensity of light emitted from an optical output portion (not shown) of the optical circuit board 1 is maximized in response to light emitted to the optical input portion via the optical fiber 2 a of the optical fiber block 2. By moving the optical fiber block 2 to the predetermined position, the optical axis of the optical fiber block 2 is aligned with respect to the optical circuit board 1. The light emitted from the optical output portion (not shown) of the optical circuit board 1 is received by the light receiving portion 50, and the position of the light receiving portion 50 may be adjusted by the light receiving portion alignment mechanism 51. The accuracy of alignment of the optical axis of the optical fiber block 2 by the operation of step S30 is on the order of nanometers. Note that the alignment accuracy in the operation of step S30 is not limited to the order of nanometers and may be performed to the order of micrometers.

[0035] Next, the resistance value applied to the optical fiber block 2 is calculated by the resistance measuring unit 60 to measure a reference value for calculating the degree of cure of the adhesive 3 (step S40). The resistance value is measured when the optical fiber block 2 is aligned in step S30, and indicates how much force the optical fiber block 2 is subjected to in the alignment operation of the optical fiber aligning mechanism 20. The resistance value is used to determine whether to perform an alignment operation while the adhesive 3 is curing, which will be described later.

[0036] Next, with the optical circuit board 1 and the optical fiber block 2 aligned via the adhesive 3, curing of the adhesive 3 is started (step S50). In step S50, the adhesive curing unit 40 determines the curing time and then irradiates the adhesive 3 with ultraviolet light or raises the ambient temperature to cure the adhesive 3.

[0037] Next, after the start of curing of the adhesive 3, if the time detected by the adhesive curing time detection mechanism 40a has not reached the set value (step S51, NO), and if the resistance value calculated in step S40 has not reached the threshold value (step S52, NO), an alignment operation of the optical fiber block 2 with respect to the optical circuit board 1 is performed (step S60). By step S60, it is possible to correct positional deviation caused by curing shrinkage of the adhesive 3 as it cures.

[0038] Next, the resistance value applied to the optical fiber block 2 during the alignment operation performed in step S60 is calculated by the resistance measuring unit 60, and the degree of hardening of the adhesive 3 is calculated based on the previously measured reference value (step S70), and the processing from step S50 onwards is repeated.

[0039] 4, the resistance value increases due to a change in viscosity as the curing time of the adhesive 3 passes. When the resistance value applied to the optical fiber block 2 calculated in step S70 reaches a threshold value (step S52, YES), the alignment operation of the optical fiber block 2 with respect to the optical circuit board 1 is not performed, and when the adhesive curing time reaches a set value (step S51, YES), the curing of the adhesive 3 is terminated (step S80). The threshold resistance value is set appropriately depending on the physical properties of the adhesive 3 used and the shape of the optical fiber block 2.

[0040] Through the above steps, the optical waveguides are connected.

[0041] According to the first embodiment, the optical fiber block 2 holding the optical fiber 2a can be aligned with respect to the optical circuit board 1 by referring to the degree of cure and adhesive cure time of the adhesive 3 so as to maximize the intensity of light emitted from the optical circuit board 1. Specifically, as described above, steps S51, S52, S60, and S70 are repeatedly performed after step S50. In this way, it is possible to suppress misalignment between the optical fiber 2a and the optical input portion of the optical circuit board with a simple configuration regardless of the shape of the bonded object such as the optical fiber block 2, thereby achieving highly efficient optical coupling.

[0042] [Embodiment 2] Embodiment 2 according to the present disclosure will be described below with reference to the drawings. In the following description, differences from the above-described embodiment 1 will be mainly described, and descriptions of commonalities will be omitted or simplified as appropriate.

[0043] An optical waveguide connection device D2 according to a second embodiment of the present disclosure will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a diagram showing a configuration example of the optical waveguide connection device D2 according to the second embodiment of the present disclosure, and Fig. 6 is a control system diagram of the optical waveguide connection device D2 according to the second embodiment of the present disclosure.

[0044] The optical waveguide connecting device D2 in the second embodiment includes a cure measuring unit 70 instead of the resistance measuring unit 60.

[0045] The curing degree measuring unit 70 is a unit that measures the curing degree of the adhesive 3 as it is cured by the adhesive curing unit 40. For example, when the adhesive 3 is an epoxy resin, the curing degree measuring unit 70 is a device that calculates the curing degree by measuring the infrared absorption spectrum using Fourier transform infrared spectroscopy. As the curing reaction progresses, the molecular structure of the epoxy resin changes, and the peak intensity of the absorption spectrum decreases due to a decrease in the epoxy groups. The curing degree can be measured by measuring the ratio of unreacted material to reacted material from the spectral change of the adhesive—in other words, by calculating the epoxy group peak intensity ratio based on the peak intensity of the structure that does not contribute to the reaction. The curing degree measuring unit 70 can be of any type, as long as it can measure the curing degree of the adhesive 3. Information about the curing degree of the adhesive 3 measured by the curing degree measuring unit 70 is input to the control unit C1.

[0046] Here, a method for connecting optical waveguides using the optical waveguide connection device D2 according to the second embodiment will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is a flowchart illustrating the method for connecting optical waveguides according to the second embodiment of the present disclosure, and Fig. 8 is a diagram for explaining changes in the degree of cure according to the second embodiment of the present disclosure.

[0047] Steps S10, S20, S30, and S50 are the same as those in the first embodiment.

[0048] Next, after curing of the adhesive 3 begins (step S50), the current degree of cure of the adhesive 3 is measured by the cure degree measuring unit 70 (step S90). When a UV-curable adhesive is used, the photopolymerization initiator absorbs UV light as UV irradiation begins, generating radicals or cations, which then bond to monomers or oligomers, the main components of UV curing, and the polymerization reaction proceeds. At this time, the degree of cure measured by the cure degree measuring unit 70 increases with increasing viscosity in proportion to the consumption of the initiator.

[0049] Next, if the time detected by the adhesive curing time detection mechanism 40a has not reached the set value (step S51, NO), and if the degree of curing of the adhesive 3 calculated in step S90 has not reached the threshold value (step S91, NO), an alignment operation of the optical fiber block 2 with respect to the optical circuit board 1 is performed (step S60), and the processing from step S50 onwards is repeatedly performed. This step S60 makes it possible to correct positional deviation caused by curing shrinkage of the adhesive 3 as it cures.

[0050] 8, the degree of cure increases as the curing time of the adhesive 3 passes. When the degree of cure of the adhesive 3 calculated in step S90 reaches the threshold value (step S91, YES), the alignment operation of the optical fiber block 2 with respect to the optical circuit board 1 is not executed, and when the adhesive curing time reaches the set value (step S51, YES), the curing of the adhesive 3 is terminated (step S80).

[0051] Here, the threshold value of the degree of cure measured in step S90 is, for example, 70 percent. Note that the threshold value of the degree of cure is not limited to 70 percent and may be appropriately set within the range of 50 percent to 99 percent depending on the physical properties of the adhesive 3 used and the shape of the optical fiber block 2.

[0052] According to the second embodiment, as described above, by repeatedly performing steps S90, S51, S91, and S60 after step S50, it is possible to suppress misalignment between the optical fiber 2a and the optical input portion of the optical circuit board 1 with a simple configuration regardless of the shape of the adhesive material such as the optical fiber block 2, and to achieve highly efficient optical coupling.

[0053] In the first or second embodiment, the degree of cure of the adhesive 3 can be measured at all times until the curing of the adhesive 3 is completed.

[0054] Although the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various changes or modifications will be apparent to those skilled in the art. Such changes or modifications should be understood to be included within the scope of the present disclosure as defined by the appended claims, unless they depart therefrom. Furthermore, changes in the combination or order of elements in the embodiments may be made without departing from the scope and spirit of the present disclosure.

[0055] It should be noted that any of the various embodiments or modifications described above can be appropriately combined to achieve the effects of each. In addition, combinations of embodiments, combinations of examples, or combinations of embodiments and examples are possible, and combinations of features from different embodiments or examples are also possible.

[0056] According to the present disclosure, the optical fiber block that holds the optical fiber can be aligned with the optical circuit board so that the intensity of light emitted from the optical circuit board is maximized by referring to the degree of cure of the adhesive and the adhesive curing time. Therefore, it is possible to provide an optical waveguide connecting method and an optical waveguide connecting device that can suppress positional deviation between the optical fiber and the optical input portion of the optical circuit board with a simple configuration regardless of the shape of the adhesive, such as the optical fiber block, and achieve highly efficient optical coupling.

[0057] An embodiment of the present disclosure can be suitably used for an optical waveguide connection method and an optical waveguide connection device. Furthermore, the optical waveguide connection method and optical waveguide device according to the above aspect of the present disclosure can permanently connect an optical fiber block and an optical circuit board with high efficiency, and therefore can be applied in fields such as high-speed optical communications typified by silicon photonics and high-precision sensing using laser light.

[0058] REFERENCE SIGNS LIST 1 Optical circuit board 2 Optical fiber block 2a Optical fiber 2b Holder 3 Adhesive 10 Sample stage 11 Sample adjustment mechanism 20 Optical fiber alignment mechanism 20a Motor 20b Encoder 20d First fixed part 20e First movable part 30 Adhesive supply part 40 Adhesive curing part 40a Adhesive curing time detection mechanism 50 Light receiving part 51 Light receiving part alignment mechanism 51d Second fixed part 51e Second movable part 60 Resistance measurement part 70 Curing degree measurement part 100 Fixing base C1 Control part D1, D2 Optical waveguide connection device

Claims

1. Supplying an adhesive near an optical input portion on an optical circuit board; aligning an optical fiber block that holds an optical fiber with respect to the optical circuit board so that the intensity of light emitted from the optical circuit board is maximized; Initiating the curing of the adhesive; Measure the degree of cure of the adhesive; During the curing of the adhesive, an adhesive curing time is measured; a curing time of the adhesive and the adhesive curing degree, and aligning the optical fiber block that holds the optical fiber with respect to the optical circuit board so that the intensity of light emitted from the optical circuit board is maximized.

2. 2. The optical waveguide connection method according to claim 1, wherein the alignment of the optical fiber block during the curing of the adhesive is repeatedly performed when the degree of curing is equal to or lower than a certain threshold value.

3. 2. The optical waveguide connection method according to claim 1, wherein the degree of cure is measured by measuring a resistance value applied to the optical fiber block when the optical fiber block is aligned.

4. 2. The optical waveguide connection method according to claim 1, wherein the degree of cure is measured by measuring a ratio of unreacted material to reacted material from a spectral change of the adhesive during curing of the adhesive.

5. 5. The optical waveguide connection method according to claim 4, wherein the degree of cure of the adhesive is constantly measured until the curing of the adhesive is completed.

6. An adhesive supply unit that supplies adhesive to the vicinity of an optical input unit provided on an optical circuit board; a light receiving unit that receives light emitted from the optical circuit board; an optical fiber alignment mechanism that aligns an optical fiber block that holds an optical fiber with respect to the optical circuit board so that the intensity of the light received by the light receiving unit is maximized while the adhesive is being supplied; an adhesive curing unit that cures the adhesive; an adhesive curing time detection mechanism that detects a curing time of the adhesive when the adhesive is cured; A curing degree measuring unit for measuring the curing degree of the adhesive; A control unit for controlling the optical fiber alignment mechanism, an optical waveguide connection device in which, under the control of the control unit, the optical fiber block that holds the optical fiber is aligned with respect to the optical circuit board by the optical fiber alignment mechanism, so that the intensity of light emitted from the optical circuit board is maximized, with reference to the degree of hardening of the adhesive and the hardening time of the adhesive.

7. 7. The optical waveguide connection device according to claim 6, wherein the optical fiber alignment mechanism aligns the optical fiber block with respect to the optical circuit board so that the intensity of the light received by the light receiving unit is maximized when the degree of hardening measured by the hardening degree measuring unit is equal to or lower than a certain threshold value when the adhesive is hardened.

8. 7. The optical waveguide connection device according to claim 6, wherein the degree of cure measuring section measures the degree of cure by measuring a resistance value applied to the optical fiber block when the optical fiber block is aligned by the optical fiber alignment mechanism.

9. 7. The optical waveguide connection device according to claim 6, wherein the curing degree measuring unit measures the curing degree by measuring a ratio of unreacted material to reacted material from a spectral change of the adhesive when the adhesive curing unit hardens the adhesive.