JP6992398B2 - How to form an optical connection structure - Google Patents

Description

The present invention relates to a method for forming an optical connection structure in which two optical devices are connected by an optical waveguide made of resin.

With the development of optical communication networks, there is a strong demand for improving the degree of integration of optical communication devices and reducing the size of optical devices. In an optical circuit used as an optical communication device, a planar lightwave circuit (PLC) made of a quartz glass system having a glass as a core has been widely used. Since it has excellent coupling with optical fibers and is highly reliable as a material, it is applied to a wide variety of functional elements for optical communication such as splitters, wavelength duplexers, optical switches, and polarization control elements. ..

In recent years, in order to cope with the above-mentioned miniaturization of optical circuits, optical circuits with a high refractive index difference are designed to have a small minimum bending diameter by increasing the refractive index of the core and increasing the difference in refractive index from the cladding. Research is progressing. Further, in recent years, silicon photonics technology centered on silicon, which has strong light confinement, has been advanced, and an optical circuit smaller than that of a glass system has been realized. Silicon processes generally used in electronic components and the like can be applied to silicon photonics technology.

Further, a resin optical waveguide made of a resin such as a transparent polymer polymer is also well known. Further, as an optical modulation element, a wavelength conversion element, and an amplification element, an optical circuit having a ferroelectric material as a core, such as lithium niobate (LiNbO ₃ ), is widely used. Group III-V semiconductors such as indium phosphide (InP) and gallium arsenide (GaAs) have also been put into practical use as light emitting elements, light receiving elements, and optical modulation elements. Optical circuit integrated light emitting elements, light receiving elements, optical modulation elements, and the like are also widely applied. Since these ferroelectric systems and semiconductor-based optical waveguides also have a higher refractive index than glass, light confinement is strong, and circuit miniaturization can be expected. The above will be collectively referred to as an optical device.

With the miniaturization of optical devices as described above, the demand for miniaturization of the optical input / output unit of the optical waveguide is increasing. Conventionally, in the example of optical connection (optical connection) in the optical input / output section of a quartz glass-based PLC, the connection pitch cannot be reduced below the clad diameter of the optical fiber, so after widening the connection pitch on the optical circuit, In addition, it is common to make an optical connection with an optical fiber. This connection pitch is limited, and there is a problem that the entire optical device cannot be miniaturized if the optical input / output unit is included. Therefore, there is a demand for a technique for optical connection at a pitch or less limited by the clad diameter of the optical fiber.

Generally, in the optical connection between the optical fibers, between the optical fiber and the optical device, and between the optical devices, the connection end faces orthogonal to the optical axis of the optical device are arranged so as to face each other at the core positions of each other. A bad coupling technique is known in which positioning is performed so that there is no axis misalignment and optical connection is performed. On the other hand, a spatial optical system connection that reconnects to an optical device by condensing an optical beam emitted from a connection end face orthogonal to the optical axis of the optical device via a spatial optical system such as a lens is also widely used. ing.

In the above-mentioned bad coupling technology, the optical connection surfaces of optical devices must be arranged facing each other, and there are large mounting restrictions from the viewpoint of the consistency of the coefficient of thermal expansion and the mode diameter of waveguide light. There is a problem. Further, even in the spatial optical system coupling, there are restrictions due to the expansion of the beam diameter and restrictions on the manufacture of minute lenses, mirrors, etc., and there are technical limits in reducing the size of the connection pitch and improving mass productivity.

As a technique for breaking the above-mentioned limit, a technique for connecting the above-mentioned elements with a resin optical waveguide has been proposed. For example, an arbitrary optical three-dimensional wiring pattern is produced by optical connection using a self-formed optical waveguide or nano-level optical modeling technology using two-photon absorption as described in Non-Patent Document 1, and light is emitted in the resin. There is a method of optically connecting (optical connection) between the optical fibers, between the optical fiber and the optical device, and between the optical devices.

This is done by immersing a resist solution, which is a raw material for resin, on a substrate, condensing a light beam from a laser with a lens, etc., and inducing two-photon absorption in the condensing part of the light beam. It is a technique of curing only the resin of the above, and further moving the condensing part arbitrarily by scanning this laser, and as a result, performing stereolithography, and is also known as a stereolithography type three-dimensional printer.

In particular, as is well known, the stereolithography technology using two-photon absorption has a very small condensing size, so it is possible to perform nano-level stereolithography by combining it with a scanning unit that drives minutely. Is.

N. Lindenmann et al., "Photonic wire bonding: a novel concept for chipscale interconnects", Optics Express, vol. 20, no. 16, pp. 17667-17677, 2012.

However, the above-mentioned optical connection by stereolithography has a limitation in the wiring pattern that can be formed due to the characteristics in manufacturing. In stereolithography, a light beam once spread in space is focused by a lens to photo-cure the target resin. At this time, if there is an object that blocks the light beam, modeling is not possible. For example, assuming that the direction from the substrate that is the starting point of modeling to the laser for modeling is the height, if there is a structure that blocks the laser beam on the image side or the object side in the height direction, a stereolithographic object cannot be formed in the vicinity. There is a problem.

For example, consider a case where the optical fiber 601a and the optical fiber 601b are optically connected as shown in FIG. In stereolithography, an exposure system using a lens 602 and a laser beam 603 for modeling is used to cure the resin of the condensing unit 604 to form resin wiring. Here, in the optical fibers 601a and 601b, the upper and lower sides of the core 611 that guides light are sandwiched between the claddings 612 and 613. In this case, the position of the core 611 is deeper than that of the clad 613 when viewed from the irradiation side of the modeling laser beam 603.

Therefore, when an attempt is made to optically connect the core 611 of the optical fiber 601a whose end faces face each other and the core 611 of the optical fiber 601b, the modeling laser beam 603 is blocked by the upper clad 613. As a result, the wiring pattern of the resin directly connected to the end faces of the core 611 of the optical fiber 601a and the core 611 of the optical fiber 601b cannot be formed.

For example, in the case of an optical device such as a rib-type optical waveguide in which the upper clad has no structure such as air, that is, the core is exposed, as shown in FIG. 14, the core 702 of the optical device 701a, And the resin optical waveguide 703 can be formed in the direction along the optical axis of the core 702 of the optical device 701b. For example, the resin optical waveguide 703 can be formed by performing stereolithography in the direction along the optical axis and curing the resin so as to crawl along the waveguide direction of the core 702. By using the resin optical waveguide 703, it is possible to realize resin wiring between adiabatic optical circuits that are optically connected by evanescent coupling due to the exudation of the waveguide light waveguide through the core 702.

However, this optical connection is applicable when the core is exposed, and cannot correspond to the above-mentioned embedded optical waveguide. Further, the optical connection by the evanescent coupling has a problem that the optical connection loss is larger than that of the end face connection.

Further, the above-mentioned optical connection has a problem that there is a limitation in both the accuracy required for the wiring formation of the optical connection and the modeling size of the wiring pattern. Generally, in the above-mentioned stereolithography, the exposure system or the condensing unit is scanned while scanning on a stage or the like. The position accuracy of the stage is extremely high when driven by a commercially available high-precision piezo motor, but the movable range that guarantees this accuracy is limited to about submillimeters. Therefore, in order to optically connect the cores of two or more optical devices, it is necessary to keep the optical distance between the two optical devices within the above range, which limits the mounting or layout of the wiring pattern. Is big.

On the other hand, if a stage having a wide movable range is used, a scanning accuracy error occurs, and a model size shift, a model position shift, and the like occur. In the optical connection, the positioning accuracy of the submicron accuracy and the optical wiring pattern are required. Therefore, the above-mentioned deviation causes a large connection loss and is not suitable for the application of the optical connection. It is possible to improve the accuracy while expanding the above-mentioned modeling range by introducing a galvano mirror or the like in the scanning system, but even in this case, the accuracy is lower than that of the piezo stage and the device becomes complicated. There are drawbacks such as.

As described above, conventionally, as a wiring pattern used for optical connection, the positional relationship between two or more optical devices to be connected is limited to the modeling area, and in order to realize low connection loss, between the two optical devices. There was a problem that there was a restriction on the positional relationship of.

The present invention has been made to solve the above-mentioned problems, and to enable end-face connection between optical devices with an optical waveguide made of resin while suppressing restrictions on the positional relationship between the optical devices. With the goal.

The optical connection structure is optical with a resin core made of a resin that optically connects the first optical device, the second optical device, the optical input / output unit of the first optical device, and the optical input / output unit of the second optical device. The optical waveguide is provided with a waveguide, and the optical waveguide is deformable, and the positional relationship between the first optical device and the second optical device can be changed.

The optical waveguide is deformable in the bending direction.

The optical waveguide is deformable in the expansion and contraction direction.

In the optical connection structure, the optical waveguide includes at least one of a spiral portion, a meander-like portion, and a bent portion.

In the above optical connection structure, each of the connection portion between the first optical device and the optical waveguide and the connection portion between the second optical device and the optical waveguide is provided with a reinforcing member for reinforcing the mechanical strength of the connection. good. Further, the optical waveguide may be provided with a clad that covers the periphery of the resin core.

In the method for forming an optical connection structure according to the present invention, the end face of the optical input / output section of the first optical device and the end face of the optical input / output section of the second optical device are set as the first end face and the second end face, respectively, and the first end face and the second end face are used. The first step of arranging the second end surface perpendicular to the irradiation direction of the exposure light for exposure and toward the side to be irradiated with the exposure light, and curing the photocurable resin by irradiating the exposure light. Then, the second step of forming a photocured resin core from the first end face to the second end face and optically connecting the first end face and the second end face with an optical waveguide by the resin core, and the optical waveguide. It is provided with a third step of deforming to change the mutual positional relationship between the first optical device and the second optical device. The photocurable resin becomes a resin through which light is transmitted by photocuring, and the optical waveguide is made deformable. ing.

As described above, according to the present invention, it is possible to deform an optical waveguide using a resin core made of a resin that optically connects an optical input / output unit of a first optical device and an optical input / output unit of a second optical device. Therefore, it is possible to obtain an excellent effect that the optical devices can be connected to each other by the optical waveguide made of resin while suppressing the restriction of the positional relationship with each other.

FIG. 1 is a cross-sectional view schematically showing the configuration of an optical connection structure according to the first embodiment of the present invention. FIG. 2A is an explanatory diagram showing a state in each step for explaining a method of forming an optical connection structure according to the first embodiment of the present invention. FIG. 2B is an explanatory diagram showing a state in each step for explaining a method of forming an optical connection structure according to the first embodiment of the present invention. FIG. 2C is an explanatory diagram showing a state in each step for explaining a method of forming an optical connection structure according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing the configuration of the optical connection structure according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing the configuration of the optical connection structure according to the second embodiment of the present invention. FIG. 5 is a cross-sectional view schematically showing the configuration of the optical connection structure according to the second embodiment of the present invention. FIG. 6 is a perspective view schematically showing the configuration of the optical connection structure according to the third embodiment of the present invention. FIG. 7 is a cross-sectional view schematically showing the configuration of the optical connection structure according to the fourth embodiment of the present invention. FIG. 8 is a cross-sectional view schematically showing the configuration of the optical connection structure according to the fourth embodiment of the present invention. FIG. 9 is a cross-sectional view schematically showing the configuration of the optical connection structure according to the fifth embodiment of the present invention. FIG. 10 is a cross-sectional view schematically showing the configuration of the optical connection structure according to the sixth embodiment of the present invention. FIG. 11 is a cross-sectional view schematically showing the configuration of the optical connection structure according to the sixth embodiment of the present invention. FIG. 12 is a cross-sectional view schematically showing the configuration of the optical connection structure according to the seventh embodiment of the present invention. FIG. 13 is an explanatory diagram for explaining a method of forming an optical connection structure. FIG. 14 is a plan view (a) and a side view (b) showing the configuration of the optical connection structure.

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

[Embodiment 1]
First, the optical connection structure according to the first embodiment of the present invention will be described with reference to FIG. This optical connection structure includes a first optical device 101, a second optical device 102, and an optical waveguide 103. The first optical device 101 is, for example, an optical fiber including a core 105. Further, the second optical device 102 is, for example, a planar light wave circuit device in which an optical waveguide formed by a core 106 and a clad 106a around the core 106 is formed on a substrate 107.

The optical device may be any device that propagates light and inputs / outputs light. For example, the optical device may be a light emitting element such as a laser, a light receiving element such as a photodiode, or an optical modulator. Further, the optical device is naturally applicable to any optical functional device such as an isolator, a polarization rotation, a polarization separation element, and an optical attenuator.

The optical waveguide 103 optically connects (optically connects) the optical input / output unit 101a of the first optical device 101 and the optical input / output unit 102a of the second optical device 102. Further, the optical waveguide 103 is composed of a resin core 104 made of a resin through which light is transmitted, and is deformable. For example, the optical waveguide 103 is deformable in the bending direction. Further, the optical waveguide 103 is deformable in the expansion / contraction direction. In the first embodiment, the air around the resin core 104 is clad.

In the optical connection structure according to the first embodiment configured in this way, the positional relationship between the first optical device 101 and the second optical device 102 can be changed. In the first embodiment, the first light is in a state where the first end face 121 and the second end face 122 face each other from the state where the first end face 121 and the second end face 122 are facing in the same direction at the initial stage of manufacturing. The positional relationship between the device and the second optical device is changed.

For example, the light propagating through the first optical device 101 is input to the optical waveguide 103 at the first end surface 121 of the optical input / output unit 101a. The light input to the optical waveguide 103 at the first end surface 121 propagates through the optical waveguide 103 and is input to the second optical device 102 at the second end surface 122 of the optical input / output unit 102a.

Further, for example, the light propagating through the second optical device 102 is input to the optical waveguide 103 at the second end surface 122 of the optical input / output unit 102a. The light input to the optical waveguide 103 at the second end surface 122 propagates through the optical waveguide 103 and is input to the first optical device 101 at the first end surface 121 of the optical input / output unit 101a.

Next, the method of forming the optical connection structure according to the first embodiment of the present invention will be described with reference to FIGS. 2A, 2B, and 2C.

First, as shown in FIG. 2A, the first end surface 121 of the optical input / output unit 101a of the first optical device 101 and the second end surface 122 of the optical input / output unit 102a of the second optical device 102 are exposed for exposure. Arrange in the direction in which the light 151 is irradiated. Further, the first end surface 121 and the second end surface 122 are arranged so as to be perpendicular to the direction in which the exposure light 151 is irradiated (the optical axis 152 of the exposure light 151) (first step). In this state, the first optical device 101 and the second optical device 102 are fixed. For example, it is mechanically fixed using a fixing jig. Further, it may be fixed to the fixed substrate with an adhesive resin, wax or the like. The exposure light 151 is emitted from a light source (not shown) such as a laser, and is condensed by an optical system 153 such as a lens.

Next, as shown in FIG. 2B, the photo-curing resin is cured by irradiating with exposure light 151 to form a resin core 104 in which the photo-curing resin is photo-cured from the first end surface 121 to the second end surface 122. .. As the photo-curing resin, a resin that transmits light by photo-curing and becomes a deformable resin is used. The resin may be, for example, an elastic body. Further, the resin may have plasticity.

The resin core 104 is formed, for example, in a U shape. A resin core 104 is formed, and the first end surface 121 and the second end surface 122 are optically connected by an optical waveguide 103 formed by the resin core 104 (second step). In this step, the trajectory of the exposure science system for forming the resin may be any technique used in a 3D printer or the like, and for example, the resin is formed so as to be stacked from each of the first end face and the second end face. , The resins may be bonded to each other near the apex.

Next, the first optical device 101 and the second optical device 102 are released from the fixed state, the optical waveguide 103 is deformed, and the first optical device 101 and the second optical device 102 are mutually as shown in FIG. 2C. The positional relationship between the two is changed to a desired state (third step). In the example shown in FIG. 2C, the first light is such that the first end surface 121 and the second end surface 122 face each other from the state where the first end surface 121 and the second end surface 122 face in the same direction. The positional relationship between the device 101 and the second optical device 102 is changed.

Further, the first optical device 101 and the second optical device 102 may be arranged so that the optical axis of the first optical device 101 and the optical axis of the second optical device 102 coincide with each other. This state has the same positional relationship as the optical connection using the conventional bad coupling technology or a lens. After changing the positional relationship with each other in this way, the first optical device 101 and the second optical device 102 are fixed to a predetermined board with an adhesive, solder, machine fixing, or the like for mounting.

Here, in the second step described above, the first end surface 121 and the second end surface 122 are arranged in the direction in which the exposure light 151 is irradiated and perpendicular to the optical axis 152, and the optical waveguide 103 made of resin is used. Carry out the formation of. As a result, an optical connection structure is realized in which the two optical devices are connected by an optical waveguide 103 made of resin.

In the process of forming the optical waveguide 103 using the resin described above (second step), the connection end faces (first end face 121, second end face 122) that are the starting points of stereolithography are provided to the laser (exposure) and the lens (optical system). It can be easily observed. Further, in this case, there is no influence of the shield. From these facts, it becomes possible to form a resin optical waveguide with high efficiency and in a minute region between two optical devices.

Next, the method of stereolithography will be described in more detail.

As a first method, first, a film of a photoresist such as an ultraviolet (UV) curable resin or SU8 is applied to form an end face of an optical device. Alternatively, the end face of the optical device is immersed in a container filled with photoresist.

Next, UV light from a laser for forming an optical waveguide is condensed and irradiated via a predetermined optical system. This irradiation position is scanned to form any desired resin optical waveguide. Since the photoresist irradiated with UV light is photocured, by scanning the irradiation position, the resin is cured along the scanning trajectory to form a resin optical waveguide. For example, the light source and the optical system may be scanned using a motor, a piezostage, or the like.

As a second method, as a laser, there is a method of performing stereolithography using a femtosecond laser having a wavelength longer than the wavelength at which the photo-curing resin is cured. In this method, two-photon absorption at a wavelength at which the resin is cured is generated by a non-linear effect at a portion where the light intensity is constant by condensing the light. A resin optical waveguide is formed by scanning the condensing point where the two-photon absorption occurs in the same manner as described above. According to this method, as is well known, it is possible to perform high-precision and nano-level stereolithography.

As described above, a resin optical waveguide can be formed by removing the resin in the uncured region after molding by photocuring. Here, although the propagation distance of the resin is very small, it is preferable that the resin has a high transmittance at the wavelength of the light input / output to / from the optical device.

The resin optical waveguide (resin core) is arbitrary as long as it has a size (diameter) for propagating light, but the diameter at which the air layer propagates to the clad layer as a single mode reduces connection loss and bend loss. It is preferable from the viewpoint of reduction of. The condition of this single mode can be calculated from the refractive index of the resin. Further, from the viewpoint of performing fine bending, it is preferable that the diameter of the resin core is small. From the above two points of view, the diameter of the resin core is preferably 30 μm or less, more preferably 10 μm or less.

By the way, in terms of the accuracy of the apparatus for performing stereolithography, the distance between the central portion of the first end surface and the central portion of the second end surface is preferably 0.3 mm or less. The position accuracy of the stage that operates the stereolithography device is extremely high when driven by a commercially available high-precision piezo motor, but the movable range that guarantees that accuracy is about 0.3 mm. .. Therefore, the above-mentioned distance should be within the range of the position accuracy of the device. The curvature of the folded portion of the resin core can be arbitrarily determined by the distance between the central portion of the first end surface and the central portion of the second end surface, which is determined by the movable range of the accuracy guarantee.

By the way, as shown in FIG. 3, stereolithography may be performed in a state where the first end surface 121 and the second end surface 122 are arranged on the same plane 123. With this configuration, the first end face 121 and the second end face 122, which are the starting points / ending points of stereolithography for forming the resin core 104, can be more easily observed.

Generally, the starting point / ending point of stereolithography is determined by observing the focal position of the optical system. In the first embodiment described above, the focal position is different between the first end surface 121 and the second end surface 122, and the focal position is determined respectively. On the other hand, as described above, if the first end surface 121 and the second end surface 122 are arranged on the same plane 123, the focal positions are almost the same, and the resin is stacked from each of the first end surface and the second end surface. In the case of forming while forming, the resin core 104 can be stereolithographically formed more easily.

The positions of the first end surface 121 and the second end surface 122 may be arranged so as to have substantially the same height with mechanical mounting accuracy. Alternatively, in order to determine the positions of the first end surface 121 and the second end surface 122 with higher accuracy, the first optical device 101 and the second optical device 102 are fixed (mounted) and then diced or polished. The positions of the first end surface 121 and the second end surface 122 may be processed so as to be the same with higher accuracy. After that, by performing stereolithography in the same manner as described above, the resin core 104 can be formed more easily.

As described above, according to the first embodiment, in the formation of the optical waveguide 103, the first optical device 101 and the second optical device 102 have an arrangement relationship suitable for stereolithography, which is desired in mounting or the like. The first optical device 101 and the second optical device 102 can be arranged in a positional relationship. According to the first embodiment, after the optical waveguide 103 is formed, the arrangement of the first optical device 101 and the second optical device 102 is determined. Therefore, even if the optical waveguide 103 has a positional relationship that cannot be stereolithographically formed, it is easy to arrange the first optical device 101 and the second optical device 102. As described above, according to the first embodiment, the optical devices can be connected to each other by the optical waveguide made of resin while suppressing the restrictions on the positional relationship with each other.

[Embodiment 2]
Next, the optical connection structure according to the second embodiment of the present invention will be described with reference to FIGS. 4 and 5. This optical connection structure includes a first optical device 101, a second optical device 102, and an optical waveguide 103a. The first optical device 101 is, for example, an optical fiber including a core 105. Further, the second optical device 102 is, for example, a planar light wave circuit device in which an optical waveguide formed by a core 106 and a clad 106a around the core 106 is formed on a substrate 107.

The optical waveguide 103a optically connects (optically connects) the optical input / output unit 101a of the first optical device 101 and the optical input / output unit 102a of the second optical device 102. Further, the optical waveguide 103a is composed of a resin core 104 made of a resin through which light is transmitted and is deformable, so that the positional relationship between the first optical device 101 and the second optical device 102 can be changed. There is. The configuration described above is the same as that of the first embodiment described above.

The optical connection structure shown in FIG. 4 is an optical waveguide 103a having a loop structure (spiral portion) in a part of the resin core 104. By providing the loop structure in this way, the optical waveguide 103a can be more easily deformed. For example, by making the optical waveguide 103a bent by 90 °, as shown in FIG. 5, the first optical device and the first optical device so that each of the first end surface 121 and the second end surface 122 face in directions orthogonal to each other. The positional relationship with the second optical device can be changed. It is also possible to deform the optical waveguide 103a into a substantially linear state and then into a state of being bent by 90 °.

[Embodiment 3]
Next, the optical connection structure according to the third embodiment of the present invention will be described with reference to FIG. This optical connection structure includes a plurality of first optical devices 101, a second optical device 102'with a plurality of optical waveguides (not shown), and a plurality of optical waveguides 103. The first optical device 101 is an optical fiber similar to that of the first embodiment described above, and is arranged on the substrate 201.

The second optical device 102'is a planar light wave circuit made of, for example, a quartz glass thin film deposited and formed on a silicon substrate. Further, the second optical device 102'is not limited to this as long as it is an optical waveguide device having a waveguide mechanism. For example, as a substrate or an optical waveguide, in addition to quartz glass, a resin made of an organic substance, a semiconductor such as Si, silicon nitride (SiN), gallium arsenide (GaAs), indium phosphide (InP), or a compound semiconductor optical waveguide, niobic acid Dielectrics such as lithium (LN) and periodic polarization reversal lithium phosphide (PPLN) may be used.

Further, the second optical device 102'may be integrated with various signal processing optical circuits for processing signals and various optical functional elements for light emission, light reception, modulation, control, and the like. The optical device has its characteristics in this connection portion (connection end face), and does not depend on the circuit configuration or circuit function of the optical device.

In the third embodiment, each of the first optical device 101 and the corresponding optical waveguide of the second optical device 102'are optically connected by the optical waveguide 103. As described above, it is possible to realize an optical connection structure in which a plurality of optical fiber arrays connected to each optical waveguide are individually connected to an optical device having a plurality of optical waveguides.

[Embodiment 4]
Next, the optical connection structure according to the fourth embodiment of the present invention will be described with reference to FIGS. 7 and 8. This optical connection structure includes a first optical device 101, a second optical device 102, and an optical waveguide 103b. The first optical device 101 is, for example, an optical fiber including a core 105. Further, the second optical device 102 is, for example, a planar light wave circuit device in which an optical waveguide formed by a core 106 and a clad 106a around the core 106 is formed on a substrate 107.

The optical waveguide 103b optically connects the optical input / output unit 101a of the first optical device 101 and the optical input / output unit 102a of the second optical device 102. Further, the optical waveguide 103b is composed of a resin core 104 made of a resin through which light is transmitted and is deformable, so that the positional relationship between the first optical device 101 and the second optical device 102 can be changed. There is. The configuration described above is the same as that of the first embodiment described above.

The optical connection structure shown in FIG. 7 is an optical waveguide 103b having a spiral structure 131 in a part of the resin core 104. By providing the spiral structure 131 in this way, the optical waveguide 103b can be more easily deformed. Further, as shown in FIG. 7, two spiral structures 131 may be provided in the middle of the optical waveguide 103b, and one spiral structure 131 may be provided in the middle of the optical waveguide 103b as shown in FIG. You may. In FIG. 7, the first optical device 101 and the second optical device 102 are arranged in a state where the first end surface 121 and the second end surface 122 are arranged on the same plane 123. Further, in FIG. 8, the first optical device and the second optical device are arranged so that the first end surface 121 and the second end surface 122 face each other. By providing the spiral structure 131, the optical waveguide 103b can be deformed in the expansion / contraction direction in addition to the bending direction.

[Embodiment 5]
Next, the optical connection structure according to the fifth embodiment of the present invention will be described with reference to FIG. This optical connection structure includes a first optical device 101, a second optical device 102, and an optical waveguide 103c. The first optical device 101 is, for example, an optical fiber including a core 105. Further, the second optical device 102 is, for example, a planar light wave circuit device in which an optical waveguide formed by a core 106 and a clad 106a around the core 106 is formed on a substrate 107.

The optical waveguide 103c optically connects the optical input / output unit 101a of the first optical device 101 and the optical input / output unit 102a of the second optical device 102. Further, the optical waveguide 103c is composed of a resin core 104 made of a resin through which light is transmitted and is deformable, so that the positional relationship between the first optical device 101 and the second optical device 102 can be changed. There is. The configuration described above is the same as that of the first embodiment described above.

The optical connection structure shown in FIG. 9 is an optical waveguide 103c having a meander-like structure in a part of the resin core 104. By providing the meander structure in this way, the optical waveguide 103c can be more easily deformed. Two myunder structures may be provided in the middle of the optical waveguide 103c, or one may be provided in the middle of the optical waveguide 103c. By providing the meander structure, the optical waveguide 103c can be deformed in the expansion / contraction direction in addition to the bending direction.

[Embodiment 6]
Next, the optical connection structure according to the sixth embodiment of the present invention will be described with reference to FIG. This optical connection structure includes a first optical device 101, a second optical device 102, and an optical waveguide 103. The first optical device 101 is, for example, an optical fiber including a core 105. Further, in the second optical device 102, an optical waveguide formed by a core 106 and a clad 106a around the core 106 is formed on a substrate 107, and the optical waveguide includes an active portion and a resonator in the optical waveguide. It is an element. Further, the substrate 107 is arranged on the temperature control device 109 for stabilizing the laser oscillation wavelength.

In this case, the substrate 107 is an InP substrate or a silicon substrate. A distributed feedback (DFB) laser composed of a group III-V semiconductor layer formed by crystal growth or bonding on such a substrate 107, a distributed Bragg type (Distributed Bragg) in which a diffraction grating structure is integrated, etc. A Reflector (DBR) laser is provided. For example, it is a semiconductor laser using an InP-based semiconductor that oscillates in a single mode near 1.3 μm or 1.55 μm as an active layer.

In such an optical waveguide type laser element using a semiconductor laser, the optical waveguide 103 oscillates with a current equal to or higher than the threshold value due to current injection, outputs the laser light, and emits the light from the end face of the optical input / output unit 102a of the second optical device 102. Is incident on the optical fiber from the optical input / output unit 101a of the first optical device 101, and is output from the optical output unit at the other end. Although not shown, a power supply or a driver circuit is connected to the semiconductor laser of the second optical device 102 by wire bonding, flip chip connection, or the like.

Also in the sixth embodiment, the optical waveguide 103 optically connects (optically connects) the optical input / output unit 101a of the first optical device 101 and the optical input / output unit 102a of the second optical device 102. Further, the optical waveguide 103 is composed of a resin core 104 made of a resin through which light is transmitted, and is deformable. For example, the optical waveguide 103 is deformable in the bending direction. Further, the optical waveguide 103 is deformable in the expansion / contraction direction.

In addition to the above-described configuration, in the sixth embodiment, the mechanical strength of the connection to each of the connection portion between the first optical device 101 and the optical waveguide 103 and the connection portion between the second optical device 102 and the optical waveguide 103. A reinforcing member 108 is provided to reinforce the above. For example, when the optical waveguide 103 is an elastic body, if the optical waveguide 103 is deformed in order to change the arrangement relationship between the first optical device 101 and the second optical device 102, stress may be applied to the connection portion and the optical waveguide 103 may be damaged. Occur. In order to suppress such damage, a reinforcing member 108 is provided to reinforce the mechanical connection strength. By increasing the physical diameter with the reinforcing member 108, the connection area is increased and the adhesion with the connection end face is increased. By increasing the adhesion in this way, the positional relationship between the first optical device 101 and the second optical device 102 can be changed to a desired state more stably.

The reinforcing member 108 may be made of the same material as the base material of the optical waveguide 103 made of the resin core 104, and may be formed at the same time when the resin core 104 is formed. Further, after the resin core 104 is formed, a different resin may be separately applied so as to cover the vicinity of the root of the connection end surface, and the resin core 104 may be cured or fixed to form the reinforcing member 108. Further, instead of covering the entire circumference of the resin core 104 at the connection portion, a well-known truss structure such as reinforcement of a tower may be combined to reinforce the resin core 104 so as to hang it in the air.

Further, as shown in FIG. 11, the optical waveguide 103 may include a clad 110 that covers the periphery of the resin core 104. For example, the clad 110 may be made of a resin having plasticity and a refractive index smaller than that of the resin core 104. By forming the clad 110, the mechanical strength of the resin core 104 can be reinforced.

[Embodiment 7]
Next, the optical connection structure according to the seventh embodiment of the present invention will be described with reference to FIG. This optical connection structure includes a first optical device 101'with a plurality of optical waveguides 111, a second optical device 102'with a plurality of optical waveguides 111, and a plurality of optical waveguides 103b. The optical waveguide 103b is partially provided with a spiral structure, as in the fourth embodiment.

The first optical device 101'and the second optical device 102' are planar light wave circuits made of, for example, a quartz glass thin film deposited and formed on a silicon substrate. Further, the second optical device 102'is not limited to this as long as it is an optical waveguide device having a waveguide mechanism. For example, as a substrate or an optical waveguide 111, in addition to quartz glass, a resin made of an organic substance, a semiconductor such as Si, silicon nitride (SiN), gallium arsenide (GaAs), indium phosphide (InP), or a compound semiconductor optical waveguide, niobium Dielectrics such as lithium acid (LN) and periodic polarization inversion lithium niobate (PPLN) may be used.

Further, in the first optical device 101'and the second optical device 102', various signal processing optical circuits for processing signals and various optical functional elements for light emission, light reception, modulation, control, etc. are integrated. May be good. The optical device has its characteristics in this connection portion (connection end face), and does not depend on the circuit configuration or circuit function of the optical device.

In the seventh embodiment, each of the first optical device 101'and the corresponding optical waveguide 111 of the second optical device 102' are optically connected by an optical waveguide 103b having a spiral structure. As described above, it is possible to realize an optical connection structure in which a plurality of optical fiber arrays connected to each optical waveguide are individually connected to an optical device having a plurality of optical waveguides.

Further, according to the seventh embodiment, since the optical waveguide 103b has a spiral structure and is deformable, the first optical waveguide 111 is provided with a plurality of optical waveguides 111 even if the optical waveguide length of each optical waveguide 103b is constant. The arrangement relationship between the optical device 101'and the second optical device 102'can be changed. For example, as shown in FIG. 12, when the input / output end faces of the first optical device 101'and the input / output end faces of the second optical device 102' are at right angles while the planes of the optical devices are common. The distance between the input / output ends to be connected will be different. However, by using the optical waveguide 103b having a spiral structure and being deformable, the length of each optical waveguide can be made constant, and the loss difference between the ports can be reduced.

As described above, according to the present invention, it is possible to deform an optical waveguide using a resin core made of a resin that optically connects an optical input / output unit of a first optical device and an optical input / output unit of a second optical device. Therefore, the optical devices can be connected to each other by the optical waveguide made of resin while suppressing the restriction of the positional relationship with each other.

It should be noted that the present invention is not limited to the embodiments described above, and many modifications and combinations can be carried out by a person having ordinary knowledge in the art within the technical idea of the present invention. That is clear.

101 ... 1st optical device, 101a ... Optical input / output unit, 102 ... 2nd optical device, 102a ... Optical input / output unit, 103 ... Optical waveguide, 104 ... Resin core, 105 ... Core, 106 ... Core, 121 ... 1st End face, 122 ... Second end face.

Claims (1)

The end face of the optical input / output section of the first optical device and the end face of the optical input / output section of the second optical device are defined as the first end face and the second end face, respectively, and the first end face and the second end face are exposed light for exposure. The first step of arranging the light perpendicular to the irradiation direction and toward the side to which the exposure light is irradiated, and
By curing the photocurable resin by irradiating the exposure light, a resin core in which the photocurable resin is photocured is formed from the first end face to the second end face, and the first end face and the second end face are formed. In the second step of optically connecting the resin core with an optical waveguide,
A third step of modifying the optical waveguide to change the mutual positional relationship between the first optical device and the second optical device is provided.
The photo-curing resin becomes a resin through which light is transmitted by photo-curing.
A method for forming an optical connection structure, characterized in that the optical waveguide is deformable.

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