Optical Circuit Devices

Abstract

This optical circuit device (11) is provided with, in order, a waveguide substrate (111), an undercladding (112), a core through which resin curing light is guided, and an overcladding (115), and is provided with a resin core (121) cured by irradiating a photocurable resin with the resin curing light, and a resin cladding (122) disposed around the resin core and having a lower refractive index than the refractive index of the resin core. The resin curing light is emitted from the core through which the resin curing light is guided at one end of the optical circuit device (11), and the surface of the other end of the optical circuit device (11) is inclined toward the waveguide substrate side.　Consequently, the present invention can provide an optical circuit device with which it is possible to improve manufacturing process efficiency.

Description

[Technical Field]

[0001] The present invention relates to an optical circuit device that uses a self-written waveguide. [Background technology]

[0002] In order to cope with the recent rapid increase in Internet traffic, there is a need to expand the communication capacity of datacenter networks. In order to further expand transmission capacity and reduce power consumption, optical interconnections that transmit data using light are being introduced even for short- to medium-distance applications.

[0003] In a typical optical interconnection system, signal processing is achieved by transmitting signals between light-emitting elements such as laser diodes (LDs) and light-receiving elements such as photodiodes (PDs) arranged on a printed circuit board using optical transmission media such as optical waveguides or optical fibers.

[0004] Depending on the transmission method, optical modulators and other elements are integrated with the optical light-emitting elements or are connected discretely, and a driver that performs electrical-optical conversion is also connected. A configuration including these optical light-emitting elements, optical modulators, drivers, etc. is mounted on an electrical packaging substrate such as a printed circuit board (PCB) as an optical transmitter.

[0005] Similarly, optical processors and the like are appropriately integrated or discretely connected to the optical receiving elements, and electrical amplifier circuits and the like that perform optical-to-electrical conversion are further connected. A configuration including these optical receiving elements, optical processors, electrical amplifier circuits, etc. is mounted on a printed circuit board as an optical receiver. Optical transceivers that integrate these optical transmitters and optical receivers are mounted in packages or on printed circuit boards, and optically connected to optical transmission media such as optical fiber to achieve optical interconnection. Depending on the topology, this can also be achieved via repeaters such as optical switches.

[0006] Optical emitters, receivers, and modulators have been developed using semiconductors such as silicon and germanium, as well as III-V semiconductors such as indium phosphide (InP), gallium arsenide (GaAs), and indium gallium arsenide (InGaAs). In recent years, waveguide-type optical transceivers that integrate silicon photonics and indium phosphide optical circuits, which have optical propagation mechanisms, have been developed. Optical modulators may also use materials other than semiconductors, such as ferroelectrics like lithium niobate and polymers.

[0007] Furthermore, optical functional elements such as planar lightwave circuits made of quartz glass may be integrated with the above-mentioned optical emitters, receivers, and modulators. Optical functional elements include splitters, wavelength multiplexers / demultiplexers, optical switches, polarization control elements, and optical filters. Hereinafter, devices that integrate the above-mentioned optical emitters, receivers, modulators, optical functional elements, and amplifiers, which have the optical propagation and waveguiding mechanisms, will be referred to as optical waveguide devices. Among optical waveguide devices, optical waveguide devices using silicon photonics offer excellent integration capabilities, mass productivity, and compatibility with electrical components, and are attracting attention as key devices for realizing next-generation optical interconnections.

[0008] One typical method for connecting an optical circuit device to an optical waveguide, such as an optical fiber, is to butt-join the optical circuit and the optical waveguide to one or more end faces that handle the optical input and output of the optical circuit. For example, optical fibers, which are one type of optical waveguide, are integrated with glass or other materials with V-grooves to form an optical fiber array, and the cores of the optical fibers in this array structure are aligned and connected to the cores of the optical circuit device. In this case, to minimize connection loss, it is necessary to position (hereinafter referred to as alignment) and fix each core of the optical circuit device and each core of the optical fiber to a submicron accuracy. This alignment involves aligning (optical alignment) the optical fiber while inputting and outputting light and monitoring the power, and then fixing the optical fiber by applying an adhesive or other adhesive (active alignment, Non-Patent Document 1).

[0009] As a technology for connecting with less positioning accuracy, a self-written waveguide optical connection technology has been proposed. This technology forms a self-written waveguide by filling the gaps between the waveguide cores to be connected with a photocurable resin and irradiating the photocurable resin with resin-curing light from the cores to be connected. In this process, by emitting resin-curing light from both of the waveguide cores to be connected, a self-written waveguide is formed that absorbs the positional error of each core, thereby reducing connection loss.

[0010] As a result, good connection loss can be obtained even with mechanical positioning accuracy that does not use active alignment, and therefore self-written waveguide technology is expected to improve the mountability of optical circuit devices. In self-written waveguide technology, as shown in Figures 14A and 14B, a self-written waveguide core 821 is formed by irradiating resin curing light from core 814 of optical circuit device 81, and one end face of self-written waveguide core 821 is connected to the end face of core 814 of optical circuit device 81. In addition, one end face of the self-written waveguide core is connected to the optical fiber to be connected (not shown).

[0011] The optical circuit device may be any known optical circuit device. However, for example, in silicon photonics, it is difficult to propagate light in the visible to ultraviolet range, which is the wavelength of typical resin curing light. Therefore, as shown in FIGS. 14A and 14B, a second waveguide core 814 made of SiON, SiN, SiO2, or the like, which is transparent in the same wavelength range, is provided. The second waveguide core 814 is provided above the first waveguide core 813 and functions as a spot size converter at the signal wavelength. The resin curing light 84 propagates through the second waveguide cores 814 and 814_2 and is emitted from the end face of the optical circuit core. At this time, the resin curing light 84 is input to the second waveguide core 814 by butting an optical fiber 83 against one end of the second waveguide core 814. [Prior art documents] [Non-patent literature]

[0012] [Non-Patent Document 1] Kota Shikama, Yoshiteru A, Be, Toshiki Kishi, Koji Takeda, Takuro Fujii, Hidetaka Nishi, Takashi Matsui, Atsushi Aratake, Kazuhide Nakajima, and Shinji Matsuo, "Multicore-Fiber Receptacle With Compact Fan-In / Fan-Out Device for SDM Transceiver Applications," J.Lightwave Technol. 36, 5815-5822 (2018). Summary of the Invention [Problem to be solved by the invention]

[0013] However, in a conventional optical circuit device having a self-written waveguide, in order to input resin curing light into the optical circuit device, it was necessary to input the resin curing light at one end of the waveguide core using an optical fiber having a core coaxial with the optical circuit core. Here, when forming a self-written waveguide core (hereinafter referred to as a "resin core"), the input optical fiber, optical circuit device, resin core, and the other optical fiber or optical circuit device (not shown) to be connected are arranged in the longitudinal direction of the optical circuit core, requiring a large footprint.

[0014] Furthermore, with conventional self-written waveguide technology, it was difficult to simultaneously form self-written waveguides on multiple silicon photonics chips, making it difficult to realize the formation of self-written waveguides at the multi-chip or wafer level, for example.

[0015] As described above, conventional optical circuit devices using self-written waveguides have had issues with manufacturing process efficiency, such as the large area (footprint) required for the mounting work when forming and connecting self-written waveguides, and the inability to form multiple self-written waveguides at once. [Means for solving the problem]

[0016] In order to solve the above-mentioned problems, an optical circuit device according to the present invention comprises, in order, a waveguide substrate, an underclad, and a first waveguide core, a second waveguide core, and a spot size conversion portion; an optical circuit device comprising: The optical circuit device further comprises: The aforementioned Second Waveguide a resin core connected to one end of the core; and a resin clad disposed around the resin core and having a refractive index smaller than that of the resin core, the second waveguide core is configured to cover the first waveguide core, and the second waveguide core is optically coupled to the first waveguide core at the spot size conversion portion; The aforementioned Second Waveguide The oblique end face at the other end of the core is inclined toward the waveguide substrate, For hardening the resin core The resin curing light is incident on the upper surface of the other end portion, and the resin curing light is incident on the oblique end surface of the other end portion. Second Waveguide Reflected towards the core, is incident on the second waveguide core, The aforementioned Second Waveguide At one end of the core, Second Waveguide Emitted from the core the optical circuit device further comprises a mounting substrate, electrical contacts arranged on an upper surface of the mounting substrate, and a reflecting structure arranged between the overclad of the optical circuit device and the electrical contacts, wherein the upper surface of the mounting substrate and a surface of the overclad are arranged opposite each other, and the resin curing light incident on the oblique end face of the other end from a direction perpendicular to the upper surface of the mounting substrate is reflected by the reflecting structure and then reflected by the oblique end face of the other end toward the second waveguide core. It is characterized by: [Effects of the Invention]

[0019] According to the present invention, it is possible to provide an optical circuit device that can improve the efficiency of the manufacturing process. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic side cross-sectional view showing the configuration of an optical circuit device according to a first embodiment of the present invention. [Figure 2A] FIG. 2A is a schematic side cross-sectional view showing the configuration of an optical circuit device according to a first embodiment of the present invention. [Figure 2B] FIG. 2B is a schematic cross-sectional top perspective view showing the configuration of the optical circuit device according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a schematic side cross-sectional view showing an example of the configuration of the optical circuit device according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a schematic side cross-sectional view showing the configuration of an optical circuit device according to a second embodiment of the present invention. [Figure 5] FIG. 5 is a schematic side cross-sectional view showing the configuration of an optical circuit device according to a third embodiment of the present invention. [Figure 6] FIG. 6 is a schematic side cross-sectional view showing an example of the configuration of an optical circuit device according to the third embodiment of the present invention. [Figure 7A] FIG. 7A is a schematic side cross-sectional view showing the configuration of an optical circuit device according to a fourth embodiment of the present invention. [Figure 7B] FIG. 7B is a schematic side cross-sectional view showing an example of the configuration of the optical circuit device according to the fourth embodiment of the present invention. [Figure 8] FIG. 8 is a schematic side cross-sectional view showing the configuration of an optical circuit device according to the fifth embodiment of the present invention. [Figure 9] FIG. 9 is a schematic side cross-sectional view showing the configuration of an optical circuit device according to the sixth embodiment of the present invention. [Figure 10] FIG. 10 is a schematic side cross-sectional view showing the configuration of an optical circuit device according to the sixth embodiment of the present invention. [Figure 11] FIG. 11 is a schematic side cross-sectional view showing an example of the configuration of an optical circuit device according to the sixth embodiment of the present invention. [Figure 12] FIG. 12 is a schematic side cross-sectional view showing the configuration of an optical circuit device according to the seventh embodiment of the present invention. [Figure 13A] FIG. 13A is a schematic side cross-sectional view showing an example of the configuration of an optical circuit device according to the seventh embodiment of the present invention. [Figure 13B] FIG. 13B is a schematic side cross-sectional view showing an example of the configuration of an optical circuit device according to the seventh embodiment of the present invention. [Figure 13C] FIG. 13C is a schematic side cross-sectional view showing an example of the configuration of an optical circuit device according to the seventh embodiment of the present invention. [Figure 13D] FIG. 13D is a schematic side cross-sectional view showing an example of the configuration of an optical circuit device according to the seventh embodiment of the present invention. [Figure 14A] FIG. 14A is a schematic cross-sectional side view showing the configuration of a conventional optical circuit device. [Figure 14B] FIG. 14B is a schematic cross-sectional perspective top view showing the configuration of a conventional optical circuit device. DETAILED DESCRIPTION OF THE INVENTION

[0021] First Embodiment An optical circuit device according to a first embodiment of the present invention will be described with reference to FIGS.

[0022] <Configuration of optical circuit device> As shown in FIG. 1, the optical circuit device 11 according to this embodiment comprises, in order, a waveguide substrate 111, an underclad 112, a first waveguide core 113, a second waveguide core 114, and an overclad 115, as well as a self-written waveguide photocurable resin core (hereinafter referred to as "resin core") 121 and a photocurable resin clad (hereinafter referred to as "resin clad") 122.

[0023] Here, the waveguide layer of the optical circuit device 11 is composed of an underclad 112 , a first waveguide core 113 , a second waveguide core 114 , and an overclad 115 .

[0024] Here, the resin curing light emitted from the second waveguide core 114 of the optical circuit device 11 is irradiated onto the photocurable resin arranged on the surface from which the light is emitted, forming a photocurable resin core (hereinafter referred to as "resin core") 121. As a result, the resin core 121 is formed in contact with the surface from which the resin curing light is emitted.

[0025] In the optical circuit device 11, resin curing light is incident from the vicinity (including the end face) of an arbitrary end face (referred to as the "resin curing light incident end face" or "incident end face") 116, and is emitted from the vicinity (including the end face) of another end face (referred to as the "resin curing light emitting end face" or "emitting end face") 117. In this embodiment, the resin curing light incident end face 116 and the resin curing light emitting end face 117 are arranged in opposing positions.

[0026] Hereinafter, in the horizontal plane (surface of the waveguide substrate 111), the direction in which the resin curing light is guided in the second waveguide core 114 near the emitting end face 117 within the optical circuit device 11 (X direction in the drawing) will be referred to as the "longitudinal direction of the optical circuit core," the direction perpendicular to the longitudinal direction (Y direction in the drawing, the direction into the paper) will be referred to as the "width direction," and the direction perpendicular to the horizontal plane (surface of the waveguide substrate 111) (Z direction) will be referred to as the "thickness direction."

[0027] In the optical circuit device 11 , the resin core 121 is connected to the end face of the second waveguide core 114 at the emission end face 117 .

[0028] Furthermore, in the optical circuit device 11, the surface of the incident end face 116 is inclined to face the waveguide substrate 111 (downward in this embodiment) as an optical path conversion structure. Here, the "surface" of the surface refers to the surface facing outward from the optical circuit device 11, that is, the surface that comes into contact with the external environment such as the atmosphere.

[0029] In the optical circuit device 11, a plurality of first waveguide cores 113 and second waveguide cores 114 are arranged in the width direction (Y direction) (not shown).

[0030] The optical circuit device 11 is a known silicon photonics chip, and the optical waveguide layer is formed on a BOX layer 112 on a waveguide substrate 111. The thickness of the waveguide substrate 111 is, for example, 625 μm, which is the thickness of a standard silicon wafer.

[0031] Although not shown in the drawing, light emitting elements, light receiving elements, modulation elements, optical function elements, etc., as described in the background, are integrated, and electrical wiring layers and electrical pads are also integrated as needed.

[0032] Furthermore, the optical circuit device 11 is hybrid-integrated with an optical transmitting element or an optical modulating element made of a compound semiconductor, etc. Although not shown in the drawing, the optical circuit device 11 is mounted and fixed on a subcarrier, a package, an electric wiring board, etc.

[0033] The following description will be given taking the example of light emission from a silicon photonics chip, but the operation when light is incident on a silicon photonics chip is also reversible, and the present invention is naturally independent of the direction of light input / output.

[0034] A silicon photonics chip has an optical input / output section that inputs and outputs light to the outside at at least one optical input / output end face, and a spot size converter (SSC, arrow 113_2 in Figure 2B) and other components are integrated into the optical circuit as an edge coupler. Generally, the mode field diameter of the optical propagation mode in a silicon photonics optical circuit is very small, at 1 μm or less, but the edge coupler expands the mode field diameter to approximately 3 μm to 10 μm before the light beam is emitted (incident).

[0035] At this time, in the SSC section, the Si wire 113, which is the first waveguide core, is formed in a tapered shape so that the tip becomes thinner. The second waveguide core 114 is formed so as to cover the first waveguide core (Si wire) 113 or to be close to the first waveguide core (Si wire) 113. In the tapered Si wire, it becomes difficult to confine light within the Si core, and the mode field diameter widens, but the light gradually transitions to the second waveguide core 114, and almost all of the light transitions to the second waveguide core 114 near the light input / output end face. In this way, the second waveguide core 114 is arranged so as to be optically coupled to the first waveguide core 113. The second waveguide core 114 is made of, for example, SiON.

[0036] The shape of the Si nanowire 113 may be a nonlinear tapered shape, a multi-step tapered shape, or an SSC structure consisting of a discontinuous Si core and glass material, known as a segmented SSC, as required. The second waveguide core 114 is made of a material that can propagate the curing wavelength of the photocurable resin, and may be made of materials other than SiON, such as glass, SiON, or a polymer.

[0037] As shown in Figures 1 to 2B, a resin core 121 made of a photocurable resin is formed in the longitudinal direction of the optical circuit core so as to contact the end face of a core (second waveguide core) 114 that handles optical input and output of the optical circuit device 11. The photocurable resin is a known resin that reacts to a specific wavelength and undergoes a curing reaction. Examples of the photocurable resin include acrylic resin, epoxy resin, silicone resin, urethane resin, oxetane resin, organic-inorganic hybrids, and modified or substituted versions of these. Materials known as photoresists may also be used. The curing wavelength can be arbitrarily designed by adding an initiator or dye, and wavelengths ranging from ultraviolet light to visible light can be used, for example.

[0038] Photocurable resin core 121 is formed by gradually curing uncured resin due to resin curing light emitted from the end face of second waveguide core 114 , and is in contact with second waveguide core 114 .

[0039] Resin clad 122 is disposed around resin core 121. The refractive index of resin clad 122 is lower in the signal wavelength band than the refractive index of photocurable resin core 121. Known acrylic resin, epoxy resin, silicone resin, urethane resin, oxetane resin, etc. can be used as the resin clad material, and halogen-substituted products such as fluorinated ones may be used as appropriate to adjust the refractive index.

[0040] The cross-sectional shape of the photocurable resin core 121 can be any shape, but it is formed to be roughly similar to the mode distribution from the optical circuit core. For example, in the case of a Gaussian beam, the cross-sectional shape will be close to a circular shape. In reality, it may be elliptical depending on the mode shape.

[0041] The resin core 121 is connected to an optical component such as an optical fiber or a second optical circuit device, and functions as an intermediate waveguide between them. Note that the optical fiber, optical circuit device, polymer waveguide, and other components to be connected are omitted from the drawing.

[0042] The layout of the optical circuit of this embodiment is configured to include branching sections of second waveguide core 114 as needed, as shown in FIG. 2B, and to input resin curing light from the end of second waveguide core 114.

[0043] In this embodiment, the end face (incident end face) 116 on the resin-curing light input side is arranged at a position facing the output end face 117 on which the resin core 121 is formed, but it may be arranged on any surface. For example, by bending or curving the second waveguide core 114 by 90 degrees, the end face facing the depth of the paper (Y+ direction) or the front of the paper (Y- direction) may be used as the incident end face 116. Furthermore, as will be described later, the resin-curing light input portion of the second waveguide core 114 may be arranged on the same surface as the surface in contact with the resin core 121, or may be provided inside the optical circuit device 11.

[0044] In this embodiment, the incident end face 116 is inclined toward the waveguide substrate 111 (downward in FIG. 1) as shown in FIG. 1. In other words, the end face has an inclination angle such that the overclad 115 of the optical circuit device 11 protrudes in the X-direction relative to the waveguide substrate 111. This inclined end face (hereinafter referred to as the "resin curing light incident oblique end face" or "incident oblique end face") 116 is formed by machining such as dicing or polishing, and is set at an angle of, for example, 45°.

[0045] 2A and 2B, the input optical fiber 21 is disposed on the upper surface of the optical circuit device 11 (waveguide layer) near the oblique incident end face 116, and receives the resin curing light 22. The resin curing light 22 is, for example, light emitted from an LD with a wavelength of 405 nm, and propagates through the input optical fiber 21.

[0046] 2A, resin curing light 22 is reflected by the back surface of incident oblique end face 116, its optical path is changed by 90°, it is coupled to second waveguide core 114, and after propagating through second waveguide core 114, it is emitted from output end face 117 filled with uncured photocurable resin. In response to this resin curing light 22, resin core 121 is formed as a self-forming waveguide.

[0047] Then, before filling the cladding resin that covers the resin core, the uncured portion of the photocurable resin is removed, and a different material is filled and fixed. Note that if the resin properties allow for a difference in refractive index of the waveguide, the photocurable resin may be used as the cladding material. For example, by using a resin with a different refractive index after curing, such as by changing the curing wavelength, curing mechanism, or adding a copolymer, the refractive index can be kept lower than that of the photocurable resin core 121, and the resin can be used as the cladding material as is.

[0048] Although an example has been shown in which the input optical fiber 21 and the overclad 115 of the optical circuit device 11 are in contact with each other, a lens or the like may be inserted between the input optical fiber 21 and the optical circuit device 11. Also, a lens may be provided on the top surface of the optical circuit or on the end surface of the input optical fiber 21.

[0049] 2B, in the vicinity of the resin curing light input portion, i.e., the optical path conversion structure, the width of the second waveguide core 114 is designed to be wider as necessary. For example, the width of the second waveguide core 114 is about 2 to 4 μm in the SSC portion, but is expanded to about 10 to 50 μm in the vicinity of the resin curing light input portion.

[0050] This structure allows the positioning precision of the resin curing light to be designed with less stringent precision than conventional methods. Also, since the light output required for resin curing is generally very small, the alignment precision of the resin curing light does not need to be active alignment; for example, it can be aligned based on the precision of image observation from above.

[0051] <Effects> The effects of the optical circuit device according to this embodiment will be described below.

[0052] In conventional optical circuit devices with a resin core, in order to input resin-curing light, it was necessary to input the resin-curing light at one end of the waveguide core using an optical fiber with a core coaxial with the optical circuit core. As a result, a large footprint was required, including the alignment space for the input fiber, and it was difficult to simultaneously form self-written waveguides on multiple silicon photonics chips, posing a challenge to the efficiency of the manufacturing process.

[0053] On the other hand, with the optical circuit device according to this embodiment, when inputting resin curing light, an input optical fiber can be arranged from the top surface of the optical circuit device, which has the effect of significantly reducing the footprint. Also, since the core position can be adjusted and positioned by observing an image from the top surface of the optical circuit device, the mounting workability (manufacturing process efficiency) can be significantly improved.

[0054] Furthermore, since the input optical fiber can be inserted from the top surface, it is possible to mount a plurality of chips side by side, and it is possible to form a resin core at the wafer level, which has the effect of greatly improving the mounting workability.

[0055] The present invention can be similarly applied to optical circuit devices other than silicon photonics, such as InP integrated circuits, quartz PLCs, and LN circuits.

[0056] 3, a silica-based PLC may be used as the optical circuit device 11. Si wires and InP waveguides have strong absorption of visible to ultraviolet light, which is resin curing light, but silica PLC, LN, polymers, etc. can propagate resin curing light, making a second waveguide unnecessary.

[0057] The optical circuit device 11 and the resin core 121 may be entirely covered with a clad (resin) 122 .

[0058] 3, the oblique end face 116 for receiving the resin curing light may be coated with a highly reflective film 118. The highly reflective film coating can be easily formed by vapor deposition of a dielectric multilayer film, metal, or the like. This allows the reflection efficiency to be sufficiently high.

[0059] Furthermore, if cladding resin or other molding resin is present, it may not be possible to obtain the refractive index difference necessary for reflection with high reflection efficiency, but by coating with a highly reflective film, it is possible to achieve highly efficient reflection of resin curing light even when the entire surface is covered with resin. Naturally, these can be combined with the configuration of Figure 1 in any way.

[0060] Any known optical fiber may be used as the optical fiber. As an optical component other than an optical fiber, an optical waveguide device, for example, a polymer waveguide may be used.

[0061] Also, while an example of a 90° optical path change using a 45° mirror has been shown, the angle may be changed to a predetermined design value as long as the light can be input to the waveguide core and the resin curing light can be input from the top surface. Also, while an example has been shown in which the inclination angle of the oblique end face for input of resin curing light and the reflecting surface of the mirror component is 45° and the light path is changed by 90°, the inclination angle of the reflecting surface is not limited to this and may be any angle that allows the resin curing light incident from above to enter the waveguide core.

[0062] <Second embodiment> An optical circuit device according to a second embodiment of the present invention will be described with reference to FIG.

[0063] <Configuration of optical circuit device> In the optical circuit device according to this embodiment, the basic components are the same as those in the first embodiment, the optical circuit device is an InP circuit, and the second waveguide core 114 is a polymer.

[0064] The difference from the first embodiment is that, as shown in Fig. 4, an oblique end face 131 for receiving resin curing light is formed in the optical circuit device as an optical path conversion structure. Here, the surface of the oblique end face 131 for receiving resin curing light is inclined toward the overclad 115. Also, a certain gap is provided between the oblique end face 131 for receiving resin curing light and the second waveguide core 114 through which the resin curing light propagates.

[0065] The resin curing light is input from the upper surface of the optical circuit device 11 (waveguide), and its optical path is changed by being reflected by the high-reflection film 132 on the oblique end face 131 for receiving the resin curing light, and then input to the second waveguide core 114.

[0066] Any known method can be used to form the mirror structure in such an optical circuit device. For example, it can be formed by machining with a blade at a specified angle using a dicing tool or the like. Alternatively, it can be formed using etching techniques in wafer processing. Alternatively, a similar mirror shape can be formed by forming another rectangular groove and then applying resin and utilizing surface tension.

[0067] This embodiment can achieve the same effect as the first embodiment, that is, when inputting resin curing light, an input optical fiber can be arranged from the top surface of the optical circuit device, thereby achieving the effect of significantly reducing the footprint.

[0068] Furthermore, the core position can be adjusted and positioned by observing the image from above the optical circuit device, which greatly improves the ease of mounting.

[0069] Furthermore, since the input optical fiber can be inserted from the top surface, it is possible to mount a plurality of chips side by side, and it is possible to form a resin core at the wafer level, which has the effect of greatly improving the mounting workability.

[0070] In addition, the beveled end faces can be formed in one process, such as a wafer process, rather than on a chip-by-chip basis, which significantly improves manufacturing efficiency. Furthermore, by integrating the beveled end faces within the circuit, optical circuit devices can be made smaller.

[0071] <Third embodiment> An optical circuit device according to a third embodiment of the present invention will be described with reference to FIGS.

[0072] <Configuration of optical circuit device> In the optical circuit device according to this embodiment, the basic components are the same as those in the first embodiment.

[0073] The difference from the first embodiment is that, as shown in Fig. 5, the optical path changing structure does not include an oblique end face for the incidence of resin curing light on the optical circuit device, and instead an optical path changing component 31 is disposed and integrated with the end face 116 of the optical circuit device. Here, the inclined surface of the optical path changing component 31 slopes downward. The optical path changing component is, for example, a mirror component such as a prism mirror, and is made of glass, Si, polymer, or the like. The optical path changing component 31 is fixed to the optical circuit device 11 with an adhesive.

[0074] The resin curing light is input from an end face of the optical path changing component that is parallel to the top face of the optical circuit device, and its optical path is changed by being reflected by the back surface of the inclined surface of the optical path changing component, and then input to the second waveguide core 114.

[0075] This embodiment can achieve the same effect as the first embodiment, that is, when inputting resin curing light, an input optical fiber can be arranged from the top surface of the optical circuit device, thereby achieving the effect of significantly reducing the footprint.

[0076] Furthermore, the core position can be adjusted and positioned by observing the image from above the optical circuit device, which greatly improves the ease of mounting.

[0077] Furthermore, since the input optical fiber can be inserted from the top surface, it is possible to mount a plurality of chips side by side, and it is possible to form a resin core at the wafer level, which has the effect of greatly improving the mounting workability.

[0078] Furthermore, by performing the optical path conversion using a separate component rather than an oblique end face, there is no need to process the optical circuit device itself, improving the mass productivity of optical circuit devices. Although the optical path conversion component must be prepared separately, it is easy to mass-produce the desired mirror component and to integrate it with the optical circuit device. As a result, the yield of the entire optical circuit device can be improved.

[0079] Furthermore, as shown in FIG. 6, a beam diameter adjusting component 33 may be provided connected to the end face of the optical path changing component 31 on the resin curing light incident side.

[0080] Conventionally, when light propagates through an optical path changing component, the beam diameter of the light expands, which tends to cause mismatching of the beam diameter with the second waveguide core.

[0081] On the other hand, as shown in FIG. 6, by using a beam diameter adjusting component 33, such as a lens, a GRIN lens, or a GI fiber, to adjust the beam diameter to a desired value at the coupling portion of the second waveguide core 114, beam diameter mismatch does not occur, and resin curing light can be easily input to the second waveguide core 114.

[0082] <Fourth embodiment> An optical circuit device according to a fourth embodiment of the present invention will be described with reference to FIGS. 7A and 7B.

[0083] <Configuration of optical circuit device> In the optical circuit device according to this embodiment, the basic components are the same as those in the first embodiment.

[0084] 7A and 7B, the difference from the first embodiment is that, as an optical path changing structure, the optical circuit device does not have an oblique end face for the incidence of resin curing light, and an optical path changing component 41 is disposed close to the end face of the optical circuit device. Here, the surface of the oblique end face of the optical path changing component 41 is inclined toward the overclad 115. The optical path changing component 41 is a mirror component such as a triangular prism mirror (FIG. 7A) or a cube-shaped prism mirror (FIG. 7B), and is made of glass, Si, polymer, or the like. The optical path changing component 41 and the optical circuit device 11 are mounted on a mounting substrate 42 and fixed in place by any method.

[0085] The resin curing light is input from the upper surface of the optical path changing component 41 (upper side in FIGS. 7A and 7B), and is reflected by the optical path changing component 41 to change the optical path, and then input to the second waveguide core 114.

[0086] 7B, in consideration of the spread of the beam diameter, for example, a lens, a GRIN lens, or a GI fiber may be used as the beam diameter adjusting component 43. This allows the resin curing light to be easily input into the second waveguide core 114 by adjusting the beam diameter to a desired diameter at the coupling portion of the second waveguide core 114.

[0087] This embodiment can achieve the same effect as the first embodiment, that is, when inputting resin curing light, an input optical fiber can be arranged from the top surface of the optical circuit device, thereby achieving the effect of significantly reducing the footprint.

[0088] Furthermore, the core position can be adjusted and positioned by observing the image from above the optical circuit device, which greatly improves the ease of mounting.

[0089] Furthermore, since the input optical fiber can be inserted from the top surface, it is possible to mount a plurality of chips side by side, and it is possible to form a resin core at the wafer level, which has the effect of greatly improving the mounting workability.

[0090] Furthermore, by performing the optical path conversion using a separate component rather than an oblique end face, there is no need to process the optical circuit device itself, improving the mass productivity of optical circuit devices. Although the optical path conversion component must be prepared separately, it is easy to mass-produce the desired mirror component and to integrate it with the optical circuit device. As a result, the yield of the entire optical circuit device can be improved.

[0091] Furthermore, the optical path changing components can be mounted on the substrate using an electronic component mounting machine such as a chip mounter, which allows for mass production and further improves the ease of mounting.

[0092] The mounting substrate may be an electrical wiring board such as a PCB or build-up, a thin-film electrical rewiring layer made of resin, a ceramic substrate, or an interposer made of Si, glass, glass epoxy, resin, etc. Also, the figure shows an example of face-up mounting where the waveguide layer is on top as the mounting of the chip on the substrate, but face-down mounting can also be applied.

[0093] <Fifth embodiment> An optical circuit device according to a fifth embodiment of the present invention will be described with reference to FIG.

[0094] <Configuration of optical circuit device> In the optical circuit device according to this embodiment, the basic components are the same as those in the fourth embodiment.

[0095] The difference from the fourth embodiment is that, as shown in Fig. 8, an optical path changing component 51 is integrated into the optical circuit device 11 as an optical path changing structure. Here, the surface of the oblique end face of the optical path changing component 51 is inclined toward the overclad 115. The optical path changing component 51 is, for example, a microprism mirror.

[0096] The optical circuit device 11 has a groove (terrace, cavity) 52 in which a mirror can be mounted within the optical circuit device 11, and an optical path changing component 51 is mounted and fixed in this groove 52 by any method. The groove 52 in the optical circuit device 11 can be formed by any method such as known etching.

[0097] The resin curing light is input from the top surface of the optical path changing component 51 (above in Figure 8), and its optical path is changed by being reflected by the optical path changing component 51.The light then propagates through the gap between the optical path changing component 51 and the second waveguide core 114, and is then input to the second waveguide core 114.

[0098] As in the fifth embodiment, in consideration of the expansion of the beam diameter, adjustment may be made to obtain a desired beam diameter at the coupling portion of the second waveguide core 114 using, for example, a lens, a GRIN lens, or a GI fiber.

[0099] This embodiment can achieve the same effect as the first embodiment, that is, when inputting resin curing light, an input optical fiber can be arranged from the top surface of the optical circuit device, thereby achieving the effect of significantly reducing the footprint.

[0100] Furthermore, the core position can be adjusted and positioned by observing the image from above the optical circuit device, which greatly improves the ease of mounting.

[0101] Furthermore, since the input optical fiber can be inserted from the top surface, it is possible to mount a plurality of chips side by side, and it is possible to form a resin core at the wafer level, which has the effect of greatly improving the mounting workability.

[0102] Furthermore, there is no need to process the optical circuit device itself into beveled end faces, improving the mass productivity of optical circuit devices. Although optical path conversion components must be prepared separately, it is easy to mass-produce the desired mirror components and to integrate them with the optical circuit device. As a result, the yield of the entire optical circuit device can be improved.

[0103] Furthermore, the optical path changing components can be mounted on the optical circuit device using an electronic component mounting machine such as a chip mounter, which allows for mass production and further improves the ease of mounting. Furthermore, by integrating the optical path changing parts within the circuit, the optical circuit device can be made smaller.

[0104] Sixth Embodiment An optical circuit device according to a sixth embodiment of the present invention will be described with reference to FIGS.

[0105] <Configuration of optical circuit device> The optical circuit device according to this embodiment has the same basic components as those of the first embodiment.

[0106] The difference from the first embodiment is that the optical circuit device 11 is mounted face down on the mounting substrate 63, as shown in Fig. 9. Here, the face down mounting method uses a known flip chip connection, and the connection is made via electrical contacts such as metal contacts.

[0107] Electrical wiring (not shown) and electrical contact pads (not shown) are provided on the mounting substrate 63 and are electrically connected to the electrical wiring (not shown) and electrical contact pads of the optical circuit device.

[0108] In the optical circuit device, a reflective structure 61 is provided between the overclad 115 of the waveguide layer and the electrical contact 62. The reflective structure 61 is, for example, a gold or aluminum pad for flip-chip connection.

[0109] In this embodiment, the optical path conversion structure is such that the oblique end face 116 for resin curing light incidence is inclined toward the waveguide substrate 111 (upward in FIG. 9). In other words, the end face is formed so that the overclad 115 of the optical circuit device protrudes in the X-direction compared to the waveguide substrate 111.

[0110] 10, resin curing light 22 is input from the waveguide substrate 111 side, then refracted, and transmitted (propagates) through the waveguide layer. After transmitting through the waveguide layer, resin curing light 22 is reflected by the reflecting structure 61 and then transmitted through the waveguide layer again. Thereafter, the resin curing light 22 is reflected by the back surface of the oblique end face 116, and is input into the second waveguide core 114.

[0111] This embodiment can achieve the same effect as the first embodiment, that is, when inputting resin curing light, an input optical fiber can be arranged from the top surface of the optical circuit device, thereby achieving the effect of significantly reducing the footprint.

[0112] Furthermore, the core position can be adjusted and positioned by observing the image from above the optical circuit device, which greatly improves the ease of mounting.

[0113] Furthermore, since the input optical fiber can be inserted from the top surface, it is possible to mount a plurality of chips side by side, and it is possible to form a resin core at the wafer level, which has the effect of greatly improving the mounting workability.

[0114] Furthermore, in face-down mounting such as flip-chip connection, resin curing light can be input from the thickness direction (from above in Figure 10) without using additional mirror components, thereby expanding the flexibility of mounting methods for optical circuit devices.

[0115] In this embodiment, an example has been shown in which a metal pad for flip-chip connection is used as the reflective structure, but the same effect can be achieved by forming a highly reflective film made of a metal film or a dielectric on the top surface of the overclad instead of a metal pad.

[0116] Also, as shown in FIG. 11, a through via may be formed in the mounting substrate, and the resin curing light may be input from the through via side.

[0117] Seventh Embodiment An optical circuit device according to a seventh embodiment of the present invention will be described with reference to FIGS. 12 to 13D.

[0118] <Configuration of optical circuit device> In the optical circuit device according to this embodiment, the basic components are the same as those in the first embodiment.

[0119] The difference from the first embodiment is that an optical path conversion structure 71 is also provided on the side of the output end surface 117 where the resin core is formed. As with the first to sixth embodiments, the optical path conversion structure 71 can be applied by any method such as total reflection, a mirror, or an oblique end surface.

[0120] In this embodiment, the resin curing light propagated through second waveguide core 114 and emitted has its optical path converted by optical path converting structure 71 in the vicinity of output end face 117, including output end face 117. As a result, photocurable resin core 121 extends perpendicular to the longitudinal direction of the optical circuit core (in the thickness direction) and is formed in contact with the upper surface of overclad 115.

[0121] This embodiment can achieve the same effect as the first embodiment, that is, when inputting resin curing light, an input optical fiber can be arranged from the top surface of the optical circuit device, thereby achieving the effect of significantly reducing the footprint.

[0122] Furthermore, the core position can be adjusted and positioned by observing the image from above the optical circuit device, which greatly improves the ease of mounting.

[0123] Furthermore, since the input optical fiber can be inserted from the top surface, it is possible to mount a plurality of chips side by side, and it is possible to form a resin core at the wafer level, which has the effect of greatly improving the mounting workability.

[0124] Furthermore, by connecting the resin core to the top surface of the optical circuit device, the connection target can be placed on the top surface, further improving the ease of mounting and increasing the degree of freedom in mounting layout. For example, it is possible to realize new structures such as integrating an optical circuit device with an optical fiber at the wafer level, integrating optical circuit devices with each other, and exposing the resin core from the top surface of a resin mold package.

[0125] In this embodiment, as shown in FIG. 13A, by forming end face 116 for receiving resin curing light and end face 117 for emitting light as oblique end faces, resin core 121 can be formed on the upper surface of overclad 115.

[0126] Furthermore, as shown in FIG. 13B, another optical path changing component 72 may be integrated with the output end face 117.

[0127] 13C, an optical path changing component 73 may be mounted on the mounting substrate 42, and resin curing light may be input and output in a state where photocurable resin is filled between the second waveguide core 114 and the optical path changing component 73, thereby forming an optical path changing structure using the photocurable core 121. In this case, it is desirable to form a highly reflective film 74 made of metal or dielectric on the optical path changing component in order to ensure a sufficient difference in refractive index with the photocurable resin.

[0128] 13D, the second waveguide core 114 may be laid out so as to have a loop circuit, and the end face for inputting and outputting the resin curing light may be disposed on the same end face. In this case, the resin curing light input core (optical fiber) and the output core (optical fiber) are disposed in parallel in the width direction (Y direction).

[0129] Although not shown in the drawings, in this embodiment, as in the first to sixth embodiments, for example, an oblique emission end face may be formed in the optical circuit device, or an optical path changing component may be disposed.

[0130] In the embodiments of the present invention, when the resin curing light is reflected and made incident on the waveguide core by the configuration of the oblique end facet of the optical circuit device, the optical path conversion component, etc., it is desirable that the reflection be total reflection or reflection with a high reflectance. It is sufficient that the incident resin curing light is reflected so as to be emitted with an intensity sufficient to cure the photocurable resin.

[0131] In the embodiments of the present invention, examples of the structure, dimensions, materials, etc. of each component in the configuration of the optical circuit device are shown, but the present invention is not limited to these examples. Anything that can demonstrate the functions and effects of the optical circuit device can be used. [Industrial Applicability]

[0132] The present invention relates to an optical circuit device, and can be applied to equipment and systems such as optical communications. [Explanation of symbols]

[0133] 11 Optical circuit devices 111 a waveguide substrate; 112 Underclad 113 First waveguide core 114 Second waveguide core 115 Overclad 121 Resin Core 122 Resin clad

Claims

1. In order, a waveguide substrate, Underclad and a first waveguide core; a second waveguide core; A spot size conversion unit; Overclad and An optical circuit device comprising: The optical circuit device further comprises: a resin core connected to one end of the second waveguide core; a resin clad disposed around the resin core and having a refractive index smaller than that of the resin core; Equipped with the second waveguide core is configured to cover the first waveguide core, and the second waveguide core is optically coupled to the first waveguide core at the spot size conversion portion; the oblique end face at the other end of the second waveguide core is inclined toward the waveguide substrate, resin curing light for curing the resin core is incident on an upper surface of the other end, is reflected by an oblique end surface of the other end toward the second waveguide core, is incident on the second waveguide core, and is emitted from the second waveguide core at one end of the second waveguide core, A mounting board; an electrical contact disposed on an upper surface of the mounting substrate; a reflecting structure disposed between the overclad of the optical circuit device and the electrical contact; an upper surface of the mounting substrate and a surface of the overclad are disposed opposite each other; The resin curing light incident on the oblique end face of the other end from a direction perpendicular to the upper surface of the mounting substrate is reflected by the reflecting structure and is reflected by the oblique end face of the other end toward the second waveguide core. An optical circuit device characterized by:

2. The width of the second waveguide core in the region near the input portion of the resin curing light is wider than the width of the second waveguide core in the region other than the region near the input portion.

2. The optical circuit device according to claim 1.

3. The resin core extends parallel to the longitudinal direction of the second waveguide core.

3. The optical circuit device according to claim 1 or 2.

4. The resin core extends perpendicular to the second waveguide core.

3. The optical circuit device according to claim 1 or 2.

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