JP2019074708A - Optical connection structure and forming method thereof - Google Patents

Abstract

To provide an optical connection structure capable of being connected to each other at ends thereof via a resin optical waveguide between optical devices in a state that constraints due to positional relationship therebetween is reduced.SOLUTION: The optical connection structure comprises a first optical device 101, a second optical device 102, and an optical waveguide 103. The optical waveguide 103 optically connects a light input/output part 101a of the first optical device 101 and the light input/output part 102a of the second optical device 102. The optical waveguide 103 is further constituted of a resin core 104 formed of a light-transmitting resin, and configured to be deformable. For example, the optical waveguide 103 is configured to be deformable in a bending direction. The optical waveguide 103 is further configured to be deformable in an extension/contraction direction.SELECTED DRAWING: Figure 1

Description

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

  With the development of optical communication networks, there is a strong demand for miniaturization of optical devices by improving the degree of integration of optical communication devices. In an optical circuit used as a device for optical communication, conventionally, a planar lightwave circuit (PLC) made of a quartz glass system having a glass as a core is widely used. It is applied to a wide variety of functional devices for optical communication, such as splitters, wavelength multiplexers / demultiplexers, optical switches, polarization control elements, etc., because it is excellent in coupling with optical fibers and has high reliability as a material. .

  In recent years, in order to cope with the miniaturization of the above-mentioned optical circuit, the refractive index of the core is increased, and the difference in refractive index with the cladding is increased to design the minimum bending diameter small. Research is in progress. Further, in recent years, silicon photonics technology based on silicon with strong light confinement has been developed, and optical circuits smaller than glass-based have been realized. For silicon photonics technology, silicon processes generally used in electronic parts and the like can be applied.

Also well known are resin optical waveguides made of a resin such as a transparent high molecular weight polymer. Further, as a light modulation element, a wavelength conversion element, and an amplification element, an optical circuit having a core made of a ferroelectric material represented by lithium niobate (LiNbO ₃ ) or the like is widely used. In addition, III-V semiconductors typified by indium phosphide (InP) and gallium arsenide (GaAs) have also been put to practical use as light emitting elements, light receiving elements, and light modulation elements, and a light guiding mechanism is used for these. A wide range of applications are being made for light circuit integrated light emitting elements, light receiving elements, light modulation elements, etc. The optical waveguides of these ferroelectric systems and semiconductors also have a larger refractive index than glass, so light confinement is strong, and circuit miniaturization can be expected. The above is collectively referred to simply as an optical device.

  Along with the miniaturization of optical devices as described above, the demand for miniaturization of the light input / output portion of the optical waveguide is increasing. Conventionally, in the example of optical connection (optical connection) at the light input / output part of the silica glass PLC, the connection pitch can not be made smaller than the cladding diameter of the optical fiber, so after expanding the connection pitch on the optical circuit It is common to make an optical connection with an optical fiber. This connection pitch is a limitation, and there is a problem that the entire optical device can not be miniaturized if the light input / output unit is included. Therefore, there is a need for a technique for optically connecting at a pitch equal to or less than the pitch limited by the cladding 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 devices are arranged to face each other, There is known a bad coupling technique in which positioning and optical connection are performed so as not to cause an axial deviation. On the other hand, space optical system connection, etc., in which the light beam emitted from the connection end face orthogonal to the optical axis of the optical device is collected via a space optical system such as a lens and connected again to the optical device is widely used. ing.

  In the above-mentioned bad coupling technology, there are large restrictions on mounting from the viewpoints that the optical connection surfaces of the optical devices must be disposed facing each other, and the matching of the thermal expansion coefficient and the mode diameter of guided light, etc. There is a problem called. Also in space optical system coupling, there are restrictions due to the spread of the beam diameter, and manufacturing restrictions for micro lenses, mirrors, etc., and there is a technical limit in reducing 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-forming optical waveguide or nano-level photofabrication technology using two-photon absorption as described in Non-Patent Document 1, and light in resin There is a method of optically connecting (optically connecting) between the optical fibers, between the optical fibers and the optical devices, and between the optical devices by guiding the light.

  This is performed by immersing a resist solution as a raw material of resin on a substrate, condensing a light beam from a laser with a lens or the like, and inducing two-photon absorption in the condensing part of the light beam to condense the light It is a technique of arbitrarily moving only the resin of (1) and moving the focusing unit by scanning this laser, and as a result, performing optical shaping, which is also known as an optical shaping type three-dimensional printer.

  In particular, as is well known, as the technology of photofabrication using two-photon absorption is extremely small in condensed light size, nano-level photofabrication is possible by combining it with a micro-driving scanning unit It 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 optical connection by the above-described photofabrication has a limitation in the wiring pattern which can be formed from the feature in preparation. In stereolithography, a light beam once spread in space is condensed by a lens to photocure a target resin. At this time, if there is an object blocking the light beam, modeling can not be performed. For example, assuming that the direction from the substrate serving as the formation starting point to the formation laser is a height, if there is a structure blocking the laser light on the image side in the height direction or the object side, the optical formed article can not be formed there There is a problem called.

  For example, as shown in FIG. 13, consider the case where the optical fiber 601a and the optical fiber 601b are optically connected. In optical modeling, a resin wiring is formed by curing the resin of the light collecting portion 604 using an exposure system with a lens 602 and a shaping laser beam 603. Here, in the optical fibers 601 a and 601 b, the upper and lower portions of the core 611 for guiding light are embedded in the clads 612 and 613. In this case, the core 611 is positioned deeper than the cladding 613 when viewed from the irradiation side of the shaping laser beam 603.

  Therefore, when attempting to optically connect the core 611 of the optical fiber 601 a and the core 611 of the optical fiber 601 b whose end surfaces face each other, the shaping laser beam 603 is blocked by the upper clad 613. As a result, it is impossible to form a resin wiring pattern directly connected to the end surfaces of the core 611 of the optical fiber 601a and the core 611 of the optical fiber 601b.

  For example, in the case of an optical device such as a rib type optical waveguide in which the upper clad is air without any structure, ie, the core is exposed, as shown in FIG. 14, the core 702 of the optical device 701a, 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, if optical molding is performed in the direction along the optical axis and the resin is cured so as to be wound along the waveguide direction of the core 702, the resin optical waveguide 703 can be formed. By using the resin optical waveguide 703, it is possible to realize the resin wiring between the adiabatic optical circuits optically connected by evanescent coupling by the penetration of the waveguided light guided in the core 702.

  However, this optical connection is applicable when the core is exposed and can not cope with the embedded optical waveguide as described above. Moreover, in the optical connection by evanescent coupling, there existed a problem that the connection loss of light was large compared with end surface connection.

  Furthermore, in the above-mentioned optical connection, there is a problem that there is a limit to the accuracy required for forming the wiring of the optical connection and the formation size of the wiring pattern. In general, in the above-described optical shaping, the exposure system or the light collecting portion is shaped while being scanned by a stage or the like. The position accuracy of the stage is very high in the case of driving by a commercially available high-precision piezo motor, but the movable range for securing this accuracy is limited to about a sub-millimeter. 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-mentioned range, and there is a restriction on the mounting or the layout of the wiring pattern Is large.

  On the other hand, when a stage having a wide movable range is used, a scanning accuracy error occurs, and a formation size deviation, a formation position deviation, and the like occur. In the optical connection, since the positioning accuracy of the submicron accuracy and the optical wiring pattern are required, the deviation described above causes a large connection loss, and is not suitable for the application of the optical connection. Although it is possible to improve the accuracy while expanding the above-mentioned forming range by introducing a galvano mirror etc. to the scanning system, etc., also in this case, the accuracy is lower compared with the piezo stage etc. 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 region, and in order to realize low connection loss, between the two optical devices There is a problem that there is a restriction in the positional relationship of

  The present invention has been made to solve the above-mentioned problems, and it is possible to connect end faces of optical devices with resin optical waveguides while suppressing constraints on the positional relationship between the optical devices. With the goal.

  The optical connection structure according to the present invention comprises a resin that optically connects the first optical device, the second optical device, the light input / output unit of the first optical device, and the light input / output unit of the second optical device. The optical waveguide is made deformable, and the positional relationship between the first optical device and the second optical device can be changed.

  In the above optical connection structure, the optical waveguide is deformable in the bending direction.

  In the above optical connection structure, the optical waveguide is deformable in the expansion and contraction direction.

  In the above optical connection structure, the optical waveguide includes at least one of a helical portion, a meander 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 may be provided with a reinforcing member for reinforcing the mechanical strength of the connection. Good. In addition, the optical waveguide may include a clad that covers the periphery of the resin core.

  In the method of forming an optical connection structure according to the present invention, the end face of the light input / output portion of the first optical device and the end face of the light input / output portion of the second optical device are respectively a first end face and a second end face, A first step of arranging the second end face perpendicular to the irradiation direction of the exposure light for exposure and toward the side irradiated with the exposure light, and curing the photocurable resin by irradiating the exposure light. A second step of forming a resin core in which a photocurable resin is photocured from the first end face to the second end face, and optically connecting the first end face and the second end face with the optical waveguide by the resin core; The third step of deforming to change the positional relationship between the first optical device and the second optical device, the photo-curing resin becomes a resin that transmits light by photo-curing, and the optical waveguide is made deformable ing.

  As described above, according to the present invention, it is possible to deform the optical waveguide by the resin core made of resin that optically connects the light input / output unit of the first optical device and the light input / output unit of the second optical device. Because of this, it is possible to obtain an excellent effect that the end faces of the optical devices can be connected with the optical waveguide by the resin in a state in which the restriction of the positional relationship between the optical devices is suppressed.

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

First Embodiment
First, an optical connection structure according to the first embodiment of the present invention will be described with reference to FIG. The 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 the core 105. The second optical device 102 is, for example, a planar lightwave circuit device in which an optical waveguide having a core 106 and a cladding 106 a 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, an optical modulator, or the like. Also, 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 light input / output unit 101 a of the first optical device 101 and the light input / output unit 102 a of the second optical device 102. Further, the optical waveguide 103 is made of a resin core 104 made of a resin that transmits light, and is made deformable. For example, the optical waveguide 103 is deformable in the bending direction. Further, the optical waveguide 103 is deformable in the expansion and contraction direction. In the first embodiment, the air around the resin core 104 is used as a clad.

  In the optical connection structure according to the first embodiment configured as described above, the positional relationship between the first optical device 101 and the second optical device 102 can be changed. In the first embodiment, when the first end surface 121 and the second end surface 122 face each other from the state in which the first end surface 121 and the second end surface 122 face in the same direction at the initial stage of manufacture, the first light The positional relationship between the device and the second light 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 face 121 of the light input / output unit 101a. The light input to the optical waveguide 103 at the first end face 121 propagates through the optical waveguide 103 and is input to the second optical device 102 at the second end face 122 of the light input / output unit 102 a.

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

  Next, a 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 light input / output unit 101a of the first optical device 101 and the second end surface 122 of the light input / output unit 102a of the second optical device 102 are exposed for exposure. It is arranged in the direction in which the light 151 is emitted. Further, the first end surface 121 and the second end surface 122 are arranged 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 light device 101 and the second light device 102 are fixed. For example, it fixes mechanically using a fixing jig. In addition, it may be fixed to the fixed substrate by an adhesive resin, a wax or the like. The exposure light 151 is emitted from a light source (not shown) such as a laser and condensed by an optical system 153 such as a lens.

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

  The resin core 104 is formed, for example, in a U-shape. The resin core 104 is formed, and the first end face 121 and the second end face 122 are optically connected by the optical waveguide 103 by the resin core 104 (second step). In this process, the trajectory of the exposure 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. , And bonding resin to each other near the top.

  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 as shown in FIG. 2C, the first optical device 101 and the second optical device 102 mutually The positional relationship of is changed to a desired state (third step). In the example shown in FIG. 2C, the first light is set such that 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 face in the same direction. The positional relationship between the device 101 and the second light device 102 is changed.

  Further, the first optical device 101 and the second optical device 102 may be disposed in a state where 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 is equivalent to the optical connection using a conventional bad coupling technique or a lens. After changing the positional relationship between each other in this manner, the first light device 101 and the second light device 102 are fixed and mounted on a predetermined base by an adhesive, solder, mechanical fixation, or the like.

  Here, in the second step described above, the first end face 121 and the second end face 122 are disposed 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 Implement the formation of As a result, an optical connection structure is realized in which two optical devices are connected by the optical waveguide 103 made of resin.

  In the step (second step) of forming the optical waveguide 103 with the above-described resin, connection end faces (first end face 121, second end face 122) serving as a starting point of optical shaping for the laser (exposure) and the lens (optical system) It can be easily observed. Also in this case, there is no influence of the shield. From these facts, it is possible to form a resin optical waveguide with high efficiency and a minute area between two optical devices.

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

  As a first method, first, an ultraviolet (UV) curable resin or a photoresist film typified by SU 8 is applied to form an end face of the optical device. Alternatively, the end face of the optical device is dipped in a container filled with photoresist.

  Next, UV light from a laser for forming an optical waveguide is condensed and irradiated through a predetermined optical system. The irradiation position is scanned to form any desired resin optical waveguide. Since the photoresist irradiated with the UV light is photocured, the resin is cured along the scanning path by scanning the irradiation position, and a resin optical waveguide can be formed. For example, the light source and the optical system may be scanned using a motor or a piezo stage.

  As a second method, there is a method in which optical shaping is performed using a femtosecond laser having a wavelength longer than a wavelength at which a photocurable resin cures as a laser. In this method, two-photon absorption of a wavelength at which the resin cures is generated by a non-linear effect at a location where the light intensity is made constant by condensing. A resin optical waveguide is formed by scanning the light-condensed part where this two-photon absorption occurs as described above. According to this method, as well known, it is possible to perform high-precision and nano-level photofabrication.

  As described above, the resin optical waveguide can be formed by removing the resin in the uncured region after shaping by light curing. Here, as the resin, although the propagation distance is minute, it is preferable that the transmittance is high at the wavelength of light input to and output from the optical device.

  The resin optical waveguide (resin core) is optional as long as it has a size (diameter) for propagating light, but it is a diameter for propagating the air layer to the cladding layer as a single mode, reduction of connection loss and bending loss From the viewpoint of reduction of This single mode condition can be calculated from the refractive index of the resin. Furthermore, from the viewpoint of micro bending, the smaller the diameter of the resin core, the better. From the viewpoint of the above two points, the diameter of the resin core is preferably 30 μm or less, more preferably 10 μm or less.

  By the way, the distance between the central portion of the first end surface and the central portion of the second end surface may be 0.3 mm or less in view of the accuracy of the apparatus for performing optical shaping. The position accuracy of the stage for operating the apparatus for performing optical modeling is very high accuracy in the case of driving by a commercially available high-precision piezo motor, but the movable range for securing the accuracy is about 0.3 mm . For this reason, the above-described distance should be in the range of the positional 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 determined by the movable range of the accuracy guarantee.

  By the way, as shown in FIG. 3, the optical shaping may be performed in a state where the first end face 121 and the second end face 122 are disposed on the same plane 123. With this configuration, the first end surface 121 and the second end surface 122 that become the start point / end point of the optical shaping for forming the resin core 104 can be observed more easily.

  Generally, the start / end point of stereolithography determines the focal position by the optical system by observation. In the first embodiment described above, the focal positions are different between the first end surface 121 and the second end surface 122, and the focal positions are respectively determined. On the other hand, as described above, if the first end face 121 and the second end face 122 are arranged on the same plane 123, the focal position is almost the same, and resin is piled up from each of the first end face and the second end face. However, in the case where the resin core 104 is formed, the optical shaping of the resin core 104 can be more easily performed.

  The positions of the first end face 121 and the second end face 122 may be arranged to have substantially the same height with mechanical mounting accuracy. Alternatively, after fixing (mounting) the first optical device 101 and the second optical device 102 in order to determine the positions of the first end surface 121 and the second end surface 122 with higher accuracy, dicing or polishing is performed. The positions of the first end face 121 and the second end face 122 may be processed to be the same with higher accuracy. After that, as described above, by performing optical molding, 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 optical shaping, and are desired in mounting and the like. The first light device 101 and the second light 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, it is easy to arrange the first optical device 101 and the second optical device 102 even if the optical waveguide 103 is in a positional relationship in which the optical modeling can not be performed. As described above, according to the first embodiment, the end faces of the optical devices can be connected by the optical waveguides made of resin in a state in which the restriction of the positional relationship between the optical devices is suppressed.

Second Embodiment
Next, the optical connection structure in the second embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. 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 the core 105. The second optical device 102 is, for example, a planar lightwave circuit device in which an optical waveguide having a core 106 and a cladding 106 a around the core 106 is formed on a substrate 107.

  The optical waveguide 103 a optically connects (optically connects) the light input / output unit 101 a of the first optical device 101 and the light input / output unit 102 a of the second optical device 102. In addition, the optical waveguide 103a is formed of a resin core 104 made of a resin through which light is transmitted and is deformable, and 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 similar to that of the first embodiment described above.

  The optical connection structure shown in FIG. 4 is an optical waveguide 103 a having a loop structure (helical portion) in a part of the resin core 104. By providing the loop structure as described above, the optical waveguide 103a can be deformed more easily. For example, by setting the optical waveguide 103a to be bent by 90 °, as shown in FIG. 5, the first optical device and the second end surface 122 may be oriented in directions orthogonal to each other. The positional relationship with the second light device can be changed. Further, it is also possible to deform the optical waveguide 103a into a 90 ° bent state after being deformed into a substantially linear state.

Third Embodiment
Next, an optical connection structure according to the third embodiment of the present invention will be described with reference to FIG. The optical connection structure includes a plurality of first optical devices 101, a second optical device 102 ′ including 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 arrayed on the base 201.

  The second optical device 102 'is, for example, a planar lightwave circuit made of a quartz glass thin film deposited and formed on a silicon substrate. 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, or a semiconductor or compound semiconductor optical waveguide such as Si, silicon nitride (SiN), gallium arsenide (GaAs), indium phosphide (InP), niobate A dielectric such as lithium (LN) or periodically poled lithium niobate (PPLN) may be used.

  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 feature at this connection portion (connection end surface), and does not depend on the circuit configuration or the function of the optical device.

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

Fourth Embodiment
Next, an optical connection structure in the fourth embodiment of the present invention will be described with reference to FIGS. 7 and 8. FIG. The 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 the core 105. The second optical device 102 is, for example, a planar lightwave circuit device in which an optical waveguide having a core 106 and a cladding 106 a around the core 106 is formed on a substrate 107.

  The optical waveguide 103 b optically connects the light input / output unit 101 a of the first optical device 101 and the light input / output unit 102 a of the second optical device 102. Further, the optical waveguide 103b is made of a resin core 104 made of a resin that transmits light, and is deformable, and 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 similar to that of the first embodiment described above.

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

Fifth Embodiment
Next, an optical connection structure according to the fifth embodiment of the present invention will be described with reference to FIG. The 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 the core 105. The second optical device 102 is, for example, a planar lightwave circuit device in which an optical waveguide having a core 106 and a cladding 106 a around the core 106 is formed on a substrate 107.

  The optical waveguide 103 c optically connects the light input / output unit 101 a of the first optical device 101 and the light input / output unit 102 a of the second optical device 102. Further, the optical waveguide 103c is formed of a resin core 104 made of a resin through which light is transmitted and is deformable, and 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 similar to that of the first embodiment described above.

  In the optical connection structure shown in FIG. 9, a part of the resin core 104 is an optical waveguide 103c having a meandering structure. By providing the meander structure in this manner, the optical waveguide 103c can be deformed more easily. Two meander structures may be provided in the middle of the optical waveguide 103c, and 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 and contraction direction in addition to the bending direction.

Sixth Embodiment
Next, an optical connection structure according to a sixth embodiment of the present invention will be described with reference to FIG. The 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 the core 105. In the second optical device 102, an optical waveguide having a core 106 and a cladding 106a therearound is formed on a substrate 107, and this optical waveguide is a well-known optical waveguide type laser provided with an active portion and a resonator. It is an element. Further, the substrate 107 is disposed 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 Bragg reflector (Distributed Bragg type) in which a distributed feedback (DFB) laser composed of a III-V semiconductor layer crystal-grown or bonded to such a substrate 107 and a diffraction grating structure are integrated. A reflector (DBR) laser is provided. For example, it is a semiconductor laser having an active layer of an InP-based semiconductor that oscillates in single mode in the vicinity of 1.3 μm or 1.55 μm.

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

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

  In the sixth embodiment, in addition to the configuration described above, 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 And a reinforcing member 108 for reinforcing the For example, in the case where 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 to cause breakage. Occur. In order to suppress such breakage and the like, a reinforcing member 108 is provided to reinforce the mechanical connection strength. By increasing the physical diameter by the reinforcing member 108, the connection area is increased, and the adhesion with the connection end surface is increased. By thus increasing the adhesion, 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 formed of the same material as the base material of the optical waveguide 103 made of the resin core 104 at the same time as the resin core 104 is formed. Alternatively, 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 face, and this 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 be hollow.

  Further, as shown in FIG. 11, the optical waveguide 103 may be provided with a clad 110 which covers the periphery of the resin core 104. For example, the clad 110 may be made of a resin having a 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.

Seventh Embodiment
Next, an optical connection structure in a seventh embodiment of the present invention will be described with reference to FIG. The optical connection structure includes a first optical device 101 ′ including a plurality of optical waveguides 111, a second optical device 102 ′ including a plurality of optical waveguides 111, and a plurality of optical waveguides 103b. The optical waveguide 103 b has a helical structure in part as in the fourth embodiment.

  The first optical device 101 'and the second optical device 102' are, for example, planar lightwave circuits made of a quartz glass thin film deposited and formed on a silicon substrate. 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 the substrate or the optical waveguide 111, other than 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 A dielectric such as lithium oxide (LN) or periodically poled lithium niobate (PPLN) may be used.

  The first optical device 101 ′ and the second optical device 102 ′ are integrated with various signal processing optical circuits for processing signals, and various optical functional elements for light emission, light reception, modulation, control, etc. It is also good. The optical device has its feature at this connection portion (connection end surface), and does not depend on the circuit configuration or the 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' is optically connected by the optical waveguide 103b having a helical structure. As described above, it is possible to realize an optical connection structure in which a plurality of optical fiber arrays connected to each of the optical waveguides are individually connected to the optical device having the plurality of optical waveguides.

  Further, according to the seventh embodiment, since the optical waveguide 103b is provided with a helical structure so as to be deformable, the plurality of optical waveguides 111 may be provided 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 face of the first optical device 101 ′ and the input / output end face of the second optical device 102 ′ are orthogonal to each other with the plane of each optical device in common. The intervals between the input and output terminals to be connected will be different. However, by using a deformable optical waveguide 103b having a helical structure, it is possible to make each optical waveguide length constant, and it is also possible to reduce the loss difference between ports.

  As described above, according to the present invention, it is possible to deform the optical waveguide by the resin core made of resin that optically connects the light input / output unit of the first optical device and the light input / output unit of the second optical device. Because of this, it becomes possible to connect the end faces of the optical devices with the optical waveguide by the resin in a state in which the restriction of the positional relationship between the optical devices is suppressed.

  The present invention is not limited to the embodiments described above, and many modifications and combinations can be made by those skilled in the art within the technical concept of the present invention. It is clear.

  DESCRIPTION OF SYMBOLS 101 ... 1st optical device, 101a ... light input / output part, 102 ... 2nd optical device, 102a ... light input / output part, 103 ... optical waveguide, 104 ... resin core, 105 ... core, 106 ... core, 121 ... 1st End face, 122: second end face.

Claims (7)

A first light device,
A second light device,
An optical waveguide made of a resin core made of a resin that optically connects the light input / output unit of the first optical device and the light input / output unit of the second optical device;
The optical waveguide is deformable.
An optical connection structure, wherein the positional relationship between the first optical device and the second optical device is changeable. In the optical connection structure according to claim 1,
The optical connection structure, wherein the optical waveguide is deformable in a bending direction. In the optical connection structure according to claim 1 or 2,
The optical connection structure, wherein the optical waveguide is deformable in an expansion and contraction direction. In the optical connection structure according to any one of claims 1 to 3,
An optical connection structure comprising: at least one of a helical portion, a meander portion, and a bent portion. In the optical connection structure according to any one of claims 1 to 4,
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 connection. Connection structure. In the optical connection structure according to any one of claims 1 to 5,
The optical connection structure according to claim 1, wherein the optical waveguide includes a clad that covers the periphery of the resin core. The end face of the light input / output part of the first optical device and the end face of the light input / output part of the second optical device are respectively a first end face and a second end face, and the first end face and the second end face are exposure light for exposure A first step of disposing the film perpendicularly to the irradiation direction of the light source and toward the side to which the exposure light is irradiated;
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 A second step of optically connecting the optical waveguides with the resin core by the resin core;
And a third step of changing the positional relationship between the first optical device and the second optical device by deforming the optical waveguide.
The photocurable resin becomes a resin that transmits light by photocuring,
The method for forming an optical connection structure, wherein the optical waveguide is deformable.