Coupling device and electronic device including the same

Abstract

The present invention provides a coupling device and an electronic device including the same. [Solution] The coupling device includes a substrate having a first surface and a second surface facing each other, and a third surface located between the first surface and the second surface and connected to the first surface and the second surface, and one or more coupling waveguides extending from the first surface to the second surface within the substrate, each of the one or more coupling waveguides being formed to be drawn inward from the third surface into the substrate, and including a first end and a second end, the first end being exposed to the first surface side and the second end being located inside the substrate and forming a transmission path in a first direction parallel to the third surface, and a second waveguide including a third end and a fourth end, the third end being located adjacent to the first waveguide inside the substrate and the fourth end being exposed to the second surface side, the third end and the fourth end being located at different distances from the third surface.

Description

Technical Field

[0001] The disclosed embodiments relate to a coupling device and an electronic device including the same.

Background Art

[0002] Optical interconnect is a technology that converts electrical data into optical signals for transmission. Starting from intercontinental (thousands of kilometers) optical communications in the 1980s, it has gradually expanded to shorter distances through connections between cities (tens to hundreds of kilometers), between data centers (several to tens of kilometers), and between racks within a data center (tens to several kilometers). The background is the exponentially increasing demand for data transfer.

[0003] Electrical interconnect conducts electricity through copper wires to transfer charges, but there is a problem that the power efficiency decreases due to the skin effect where the resistance of the wire increases as the transmission speed increases. On the other hand, optical interconnect has no such problem and has gradually replaced electrical interconnect in long-distance communications where its advantages are clear. In such optical communications, the light transmitted through an optical fiber must be switched back to an electrical signal again. Therefore, various techniques for connecting a PIC (photonic IC) equipped with an optical element for optical-electric conversion and an optical fiber have been explored.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Provide a coupling device that can be used for connecting an optical fiber and a PIC.

Means for Solving the Problems

[0005] According to the embodiment, a coupling device is provided, comprising: a substrate having a first surface and a second surface facing each other, and a third surface located between the first surface and the second surface and connected to the first surface and the second surface; and one or more coupling waveguides extending from the first surface to the second surface within the substrate, each of the one or more coupling waveguides being formed to be drawn inward from the third surface into the substrate, and including a first end and a second end, the first end being exposed to the first surface side, and the second end being located inside the substrate and forming a transmission path in a first direction parallel to the third surface; and a second waveguide including a third end and a fourth end, the third end being located adjacent to the first waveguide inside the substrate, the fourth end being exposed to the second surface side, and the third and fourth ends being located at different distances from the third surface.

[0006] The refractive index of the first waveguide and the refractive index of the second waveguide may be different from each other.

[0007] The difference between the refractive index of the first waveguide and the refractive index of the second waveguide may be 0.003 or less.

[0008] The adjacent arrangement of the first waveguide and the second waveguide can be set up so that light traveling through the second waveguide is transmitted to the first waveguide.

[0009] When viewed from a second direction parallel to the third surface and perpendicular to the first direction, the first waveguide and the second waveguide may be arranged within the substrate such that a portion of their regions overlap.

[0010] The distance in the second direction between a portion of the first waveguide and a portion of the second waveguide may be 3 μm or less.

[0011] The overlapping length between a portion of the first waveguide and a portion of the second waveguide may be 0.1 mm or more and 5 mm or less.

[0012] When viewed from a third direction perpendicular to the third surface, the substrate may be arranged such that a portion of the first waveguide and the second waveguide overlap.

[0013] The length of the first waveguide may be 50% or more of the length of the substrate in the first direction.

[0014] The coupling waveguide may further include a directional coupler positioned parallel to the first waveguide and made of the same material as the first waveguide, between the first waveguide and the second waveguide.

[0015] One end of the directional coupler may be in contact with the third end.

[0016] The second waveguide can form a transmission path in which the distance from the third surface gradually increases as it moves from the third end to the fourth end.

[0017] The first waveguide can be formed by implanting ions into the material constituting the substrate.

[0018] The second waveguide can be formed by modifying the material constituting the substrate with a laser.

[0019] The one or more coupling waveguides may include a plurality of coupling waveguides having different distances from the third surface to the fourth end.

[0020] The coupling device may further include a third waveguide extending from the first surface to the second surface, at a constant distance from the third surface, and made of the same material as the first waveguide.

[0021] The coupling device may further include alignment marks formed so as to be drawn inward from the third surface to the substrate.

[0022] The alignment marks may be made of the same material as the first waveguide.

[0023] The coupling device may further include a guide pin hole formed so that the second surface side in the substrate is open.

[0024] The substrate may be made of a glass material.

[0025] According to an embodiment, there are provided steps of preparing a substrate, forming a first waveguide having a transmission path with a constant distance from the surface of the substrate in the substrate, forming a second waveguide having a transmission path with a non-constant distance from the surface of the substrate in the substrate, and a method of manufacturing a coupling device including the steps.

[0026] The step of forming the first waveguide may use an ion implantation method, and the step of forming the second waveguide may use a laser beam irradiation method. According to an embodiment, there is provided an electronic device including a coupling device, an optical fiber array connected to one end of the coupling device, and an optical integrated circuit connected to the other end of the coupling device. The coupling device includes a substrate having a first surface and a second surface facing each other, and a third surface located between the first surface and the second surface and connected to the first surface and the second surface, and one or more coupling waveguides extending from the first surface to the second surface in the substrate. Each of the one or more coupling waveguides is formed to be drawn into the inside of the substrate from the third surface, includes a first end portion and a second end portion, the first end portion is exposed on the first surface side, the second end portion is located inside the substrate, a first waveguide forming a transmission path in a first direction parallel to the third surface, includes a third end portion and a fourth end portion, the third end portion is disposed adjacent to the first waveguide inside the substrate, the fourth end portion is exposed on the second surface side, and the third end portion and the fourth end portion include a second waveguide located at different distances from the third surface.

Effects of the Invention

[0027] The above coupling device can optically couple different types of waveguides to each other.

[0028] The coupling waveguide provided in the coupling device includes a first waveguide and a second waveguide manufactured by different methods, and while increasing the integration degree of the coupling waveguide, an increase in manufacturing time can be minimized.

Brief Description of the Drawings

[0029] [Figure 1] It is a perspective view showing a schematic structure of a coupling device according to an embodiment. [Figure 2A] It is a perspective view showing in detail the coupling waveguide provided in the coupling device of FIG. 1. [Figure 2B] It is a side view showing a first surface of the coupling device of FIG. 1. [Figure 2C] It is a side view showing a second surface of the coupling device of FIG. 1. [Figure 3] In the coupling device of FIG. 1, it is a diagram showing a numerically simulated electromagnetic field distribution at a position where the first waveguide and the second waveguide are adjacent. [Figure 4] It is a perspective view showing a schematic structure of a coupling device according to another embodiment. [Figure 5A] It is a side view showing a first surface of the coupling device of FIG. 4. [Figure 5B] It is a side view showing a second surface of the coupling device of FIG. 4. [Figure 6A] It is a diagram showing a first surface of a coupling device according to still another embodiment. [Figure 6B] It is a side view seen from a second surface of a coupling device according to still another embodiment. [Figure 7] It is a perspective view showing a schematic structure of a coupling device according to still another embodiment. [Figure 8] It is a perspective view showing in detail the coupling waveguide provided in the coupling device of FIG. 7. [Figure 9]This is a perspective view showing in detail a coupling waveguide provided in a coupling device according to another embodiment. [Figure 10] This is a flowchart illustrating the manufacturing method of the coupling device according to the embodiment. [Figure 11] This is a schematic diagram showing an electronic device according to an embodiment. [Figure 12] This figure schematically shows an electronic device according to another embodiment. [Modes for carrying out the invention]

[0030] The embodiments will be described in detail below with reference to the attached drawings. The embodiments described are merely illustrative, and various modifications are possible from these embodiments. The same reference numerals in the following figures refer to the same components, and the sizes of the components in the drawings are exaggerated for clarity and convenience of explanation.

[0031] In the following, "top" or "above" may include not only things that are directly above and in contact with the object, but also things that are above but not in contact with the object.

[0032] Terms such as "First," "Second," etc., may be used to describe various components, but are used solely for the purpose of distinguishing one component from another. These terms do not imply that the components differ in material or structure.

[0033] A singular expression includes multiple expressions unless the context clearly indicates otherwise. Furthermore, when we say that a part "contains" a component, this means that it may contain other components, rather than excluding them, unless otherwise stated.

[0034] Furthermore, terms such as "...part" and "module" as used herein mean a unit that performs at least one function or operation, which may be embodied in hardware or software, or in a combination of hardware and software.

[0035] The use of the term "the foregoing" and similar demonstrative terms may correspond to both singular and plural.

[0036] The steps constituting the method may be performed in any order unless explicitly stated otherwise. Furthermore, the use of all illustrative terms (e.g., etc.) is solely for the purpose of detailing the technical idea and does not limit the scope of rights unless limited by the claims.

[0037] Figure 1 is a perspective view showing the schematic structure of a coupling device according to an embodiment, and Figure 2A is a perspective view showing in detail the coupling waveguide provided in the coupling device of Figure 1. Figures 2B and 2C are side views showing the first and second surfaces of the coupling device of Figure 1.

[0038] The coupling device 100 is provided for connecting two different types of waveguides and includes a substrate 110 and a coupling waveguide 140 provided on the substrate 110. The coupling device 100 can optically connect, for example, a waveguide providing an optical transmission path in direction A2 and a waveguide providing an optical transmission path in direction A1. The coupling device 100 may include one or more coupling waveguides 140. The number of coupling waveguides 140 shown is illustrative and can be varied.

[0039] The substrate 110 comprises a first surface 110a and a second surface 110b facing each other, and a third surface 110c connected to the first surface 110a and the second surface 110b between them. The third surface 110c may also be referred to as the top surface of the substrate 110. The substrate 110 is shown as a rectangular parallelepiped, but is not limited to that. The substrate 110 may be made of glass. The substrate 110 may also be made of various other transparent plastic materials.

[0040] The coupling waveguide 140 includes a first waveguide 141 and a second waveguide 142.

[0041] The first waveguide 141 is positioned so as to be drawn inward from the third surface 110c of the substrate 110. That is, the upper surface of the first waveguide 141 is the same surface as the third surface 110c, which is the upper surface of the substrate 110. The first waveguide 141 includes a first end E1 and a second end E2, the first end E1 being exposed to the first surface 110a side and the second end E2 being located inside the substrate 110. The first waveguide 141 has a refractive index different from that of the substrate 110. The refractive index of the first waveguide 141 may be greater than that of the substrate 110. The first waveguide 141 can form a transmission path parallel to the third surface 110c, with a constant distance from it. The first waveguide 141 can form a transmission path in a first direction (X direction). The first waveguide 141 may include a material in which ions have been implanted into the material constituting the substrate 110. In other words, the first waveguide 141 can be manufactured by implanting ions into the substrate 110 at the location where the first waveguide 141 is to be formed. This manufacturing method is called lithography. Waveguides manufactured in this way form a transmission path parallel to the third surface 110c of the substrate 110, as shown in the figure, and do not form a transmission path to other depth locations inside the substrate 110.

[0042] The second waveguide 142 is positioned adjacent to the first waveguide 141. The second waveguide 142 includes a third end E3 and a fourth end E4. The third end E3 is located inside the substrate 110, adjacent to the first waveguide 141, while the fourth end E4 is exposed on the second surface 110b side. The third end E3 and the fourth end E4 are at different distances from the third surface 110c. The fourth end E4 is at a different height than the third end E3. In other words, the second waveguide 141 forms a transmission path where the distance from the third surface 110c is not constant. As shown in the figure, a portion of the second waveguide 142 forms a transmission path parallel to the third surface 110c, while the remaining portion forms a transmission path where the distance from the third surface 110c gradually increases.

[0043] As shown in the figure, the third end E3 may be located at the same height as the second end E2 and the first end E1. Such an arrangement is illustrative, but not limited to, the possibility of coupling between the first waveguide 141 and the second waveguide 142 along the Y direction parallel to the third surface 110c. In other embodiments, the second waveguide 142 may be located below the first waveguide 141, and the third end E3 may be located lower than the first end E1 and the second end E2, i.e., at a greater distance from the third surface 110c, within the substrate 110. In this case, coupling between the first waveguide 141 and the second waveguide 142 may be located along the Z direction perpendicular to the third surface 110c.

[0044] The refractive index of the second waveguide 142 may be greater than that of the substrate 110. The second waveguide 142 may also contain material that has been modified by a laser from the material constituting the substrate 110. In other words, the second waveguide 142 may be manufactured by forming a laser beam focal point at the location where the second waveguide 142 is to be formed inside the substrate 110, and melting the material of the substrate 110 with high energy to change its refractive index. Such a manufacturing method is called a writing method. In this method, it is possible to form a laser beam focal point at a desired location within the substrate 110, and therefore, a three-dimensional transmission path can be formed with a wide range of distances from the third surface 110c, which is the top surface of the substrate 110.

[0045] The positional relationship between the first waveguide 141 and the second waveguide 142 can be set so that light traveling through the second waveguide 142 is transmitted to the first waveguide 141. For example, light incident on the second waveguide 142 via the fourth end E4 can be coupled to the first waveguide 141 at a position where the second waveguide 142 is adjacent to the first waveguide 141. As shown in detail in Figure 2A, the first waveguide 141 and the second waveguide 142 may be positioned such that a portion of their regions overlap when viewed from a second direction (Y direction). The second direction is parallel to the third surface 110c of the substrate 110 and perpendicular to the first direction (X direction), which is the direction of the transmission path of the first waveguide 141. The overlapping length d1 may be approximately 0.1 mm or more and 5 mm or less. At overlapping locations, the distance between the first waveguide 141 and the second waveguide 142 may be approximately 3 μm or less. These values ​​are illustrative and can be changed to appropriate values ​​that allow for coupling between the first waveguide 141 and the second waveguide 142.

[0046] The first waveguide 141 and the second waveguide 142 are manufactured from the same material, but their detailed manufacturing methods differ, and they may contain different materials and therefore have different refractive indices. The difference between the refractive indices of the first waveguide 141 and the second waveguide 142 may be about 0.003 or less. However, this is illustrative and can be changed to other values ​​within the coupling range of the first waveguide 141 and the second waveguide 142.

[0047] The coupling device 100 may further include alignment marks 180. The alignment marks 180 may be formed on the third surface 110c of the substrate 110 at a position where they are drawn into the interior of the substrate 110. The alignment marks 180 may be provided to provide a reference for alignment when forming the second waveguide 142 after forming the first waveguide 141, or when forming the first waveguide 141 after forming the second waveguide 142.

[0048] Alignment marks 180 may be manufactured together with the first waveguide 141. Alignment marks 180 may be made of the same material as the first waveguide 141. The location and number of alignment marks 180 are illustrative and not limited to those shown.

[0049] The alignment mark 180 may be formed from a different material than the first waveguide 141. For example, it may contain a photoresist material or a metallic material, and may be manufactured separately from the process of forming the first waveguide 141.

[0050] The coupling device 100 may further include guide pinholes 190. The guide pinholes 190 are holes formed inside the substrate 110 such that the second surface 110b side is open. Guide pins of an optical fiber array, for example, may be coupled to the guide pinholes 190. The location and number of the guide pinholes 190 are illustrative and not limited to those shown. The guide pinholes 190 may be provided separately from the substrate 110. For example, a socket with guide pinholes 190 formed therein may be coupled to the substrate 110.

[0051] The coupling device 100 provided by the embodiment may connect waveguides of different types, for example, a waveguide of a PIC (photonic integrated circuit) and an optical fiber. If the outer diameter of an optical fiber is about 125 μm, the distance between two adjacent optical fibers is at least 127 μm. On the other hand, the distance between adjacent waveguides of a PIC is about 2 to 3 μm. Furthermore, the mode size of light transmitted along an optical fiber, i.e., the area where light is distributed in the cross-section of the optical fiber, has a diameter of about 10 μm, while the mode size in a PIC is about 0.2 × 0.5 μm. Two waveguides with such different environmental conditions are difficult to couple with only a structure like the first waveguide 141, which can only form a two-dimensional transmission path. The coupling device 100 according to the embodiment can form transmission paths of different forms and includes a first waveguide 141 and a second waveguide 142 manufactured by other methods, and can provide an effective data transfer structure.

[0052] The coupling apparatus 100 according to this embodiment can also shorten the overall manufacturing time by appropriately utilizing the second waveguide 142, which has a relatively long manufacturing time. For example, in the coupling waveguide 140, the length of the first waveguide 141 can be made as long as possible, and the length of the second waveguide 142 can be made relatively short. The length of the first waveguide 141 in the first direction (X direction), which is the direction of the transmission path, may be 50% or more of the length of the substrate 110 in the X direction. Alternatively, the length of the first waveguide 141 in the first direction (X direction) can be 60% or more, or 70% or more of the length of the substrate 110 in the X direction. These values ​​are illustrative and not limited to them. The longer the length of the first waveguide 141 in the first direction (X direction), the shorter the length of the second waveguide 142 can be, and the total time required to manufacture the coupling waveguide 140 may be reduced.

[0053] Figure 3 shows the electromagnetic field distribution numerically simulated at the position where the first waveguide and the second waveguide are adjacent in the coupling device shown in Figure 1.

[0054] The difference between the refractive index of the first waveguide 141 and the refractive index of the second waveguide 142 is 0.0025, indicating that light transmitted through the first waveguide 141 and the second waveguide 142 is coupled to the first waveguide 142 at a position adjacent to the first waveguide 141. If the distance between the first waveguide 141 and the second waveguide 142 is 1 μm, it can be confirmed that 99.67% of the optical power is transferred to the other waveguide while traveling 1 mm.

[0055] Figure 4 is a perspective view showing a schematic structure of a coupling device according to another embodiment. Figures 5A and 5B are side views showing the first and second surfaces of the coupling device of Figure 4.

[0056] The coupling device 101 differs from the coupling device 100 shown in Figure 1 in that it further includes a third waveguide 160.

[0057] The third waveguide 160 is a waveguide that extends from the first surface 110a to the second surface 110b and maintains a constant distance from the third surface 110c. The third waveguide 160 may be made of the same material as the first waveguide 141. The third waveguide 160 may be manufactured together with the first waveguide 141. In other words, the third waveguide 160 may be positioned so as to be drawn inward from the third surface 110c of the substrate 110, and may be manufactured by ion implantation at the position where the third waveguide 160 is to be formed in the substrate 110.

[0058] As shown in Figure 5A, on the first surface 110a of the coupling device 101, the ends of the third waveguide 160 and the first end E1 of the first waveguide 141 of the coupling waveguide 140 may all be arranged in the same row. On the second surface 110b of the coupling device 101, however, as shown in Figure 5B, the ends of the third waveguide 160 may be arranged in a row, and the fourth end E4 of the second waveguide 142 of the coupling waveguide 140 may be arranged in a row at a different position from the third waveguide 160, resulting in an overall arrangement in two rows.

[0059] Figures 6A and 6B are side views showing the first and second surfaces of a coupling device according to yet another embodiment.

[0060] The coupling device 102 of this embodiment differs from the coupling device 101 of Figure 4 in that, in addition to the coupling waveguide 140 and the third waveguide 160 provided in the coupling device 101 of Figure 4, it further includes a coupling waveguide 150.

[0061] The coupling waveguide 150 is similar to the coupling waveguide 140 in that it includes the first waveguide 141 and the second waveguide 142, as described in detail in Figure 2A, but the fourth end E4 of the second waveguide 152 is located in the substrate 110 at a different depth than the fourth end E4 of the second waveguide 142. In other words, the fourth end E4 of the second waveguide 152 and the fourth end E4 of the second waveguide 142 are at different distances from the third surface 110c.

[0062] As shown in Figure 6A, on the first surface 110a of the coupling device 102, the ends of the third waveguide 160, the first end E1 of the first waveguide 141 of the coupling waveguide 140, and the first end E1 of the first waveguide 151 of the coupling waveguide 150 can all be arranged in the same row. On the second surface 110b of the coupling device 102, however, as shown in Figure 6B, the ends of the third waveguide 160 are arranged in a row, the fourth end E4 of the second waveguide 142 of the coupling waveguide 140 is arranged in a row at a different position from the third waveguide 160, and the fourth end E4 of the second waveguide 152 of the coupling waveguide 150 is arranged in yet another row, resulting in a total of three rows.

[0063] In other embodiments, the coupling device may further include a coupling waveguide having a fourth end at yet another position, that is, the ends of the coupling waveguides may be arranged in three or more rows on the second surface 110b.

[0064] Figure 7 is a perspective view showing the schematic structure of a coupling device according to yet another embodiment, and Figure 8 is a perspective view showing in detail the coupling waveguide provided in the coupling device of Figure 7.

[0065] The coupling device 103 of this embodiment differs from the coupling waveguide 140 in Figure 1 in the detailed configuration of the coupling waveguide 170.

[0066] The coupling waveguide 170 provided in the coupling device 103 includes a first waveguide 171 and a second waveguide 172, and also includes a directional coupler 173 positioned between the first waveguide 171 and the second waveguide 172.

[0067] The first waveguide 171, like the first waveguide 141 described above, has a first end E1 and a second end E2, and forms a transmission path parallel to the third surface 110c of the substrate 110.

[0068] The directional coupler 173 is positioned adjacent to the first waveguide 171 and can be aligned with the first waveguide 171. The directional coupler 173 may be formed from the same material as the first waveguide 171. The directional coupler 173 may be formed together with the first waveguide 171 in the same process during the manufacturing of the first waveguide 171. When viewed from a second direction (Y direction), the directional coupler 173 may be positioned to overlap with the first waveguide 171. The second direction is parallel to the third surface 110c of the substrate 110 and perpendicular to the first direction (X direction), which is the direction of the transmission path of the first waveguide 171. The overlapping length may be d1. The distance between the directional coupler 173 and the first waveguide 171 may be d2. d1 and d2 can be set so that light transmitted along the first waveguide 171 is coupled by the directional coupler 173. For example, d1 may be approximately 0.1 mm or more and 5 mm or less, and d2 may be approximately 3 μm or less.

[0069] The directional coupler 173 may be positioned adjacent to the second waveguide 172. The second waveguide 172, like the second waveguide 142 described above, includes a third end E3 and a fourth end E4 located at different depths within the substrate 110. One end of the directional coupler 173 may be in contact with the third end E3. The second waveguide 172 can form a transmission path whose distance from the third surface 110c gradually increases.

[0070] Other embodiments of the coupling device may include the coupling waveguide 170 illustrated in Figure 7 and the coupling waveguide 140 illustrated in Figure 1.

[0071] Furthermore, coupling devices of other embodiments may include a planar third waveguide 160 as illustrated in Figure 4, along with the coupling waveguide 170 illustrated in Figure 7.

[0072] Furthermore, while the coupling device of another embodiment includes a coupling waveguide 170 with the structure illustrated in Figure 7, the depth position of the fourth end E4 within the substrate 110 may be two or more types.

[0073] Figure 9 is a perspective view showing in detail a coupling waveguide provided in a coupling device according to yet another embodiment.

[0074] The coupling waveguide 240 provided in the coupling device of this embodiment differs from the coupling waveguide 140 shown in Figure 2A in terms of the relative positional relationship between the first waveguide 241 and the second waveguide 242.

[0075] The second waveguide 242 may be located below the first waveguide 241, i.e., deeper than the first waveguide 241, within the substrate (110 in Figure 1). The third end E3 has a different height position than the second end E2, meaning that the third end E3 and the second end E2 are at different distances from the third surface (110c in Figure 1).

[0076] The first waveguide 241 and the second waveguide 242 are arranged such that their regions partially overlap when viewed from the Z direction. In this arrangement, coupling between the first waveguide 241 and the second waveguide 242 can occur along the Z direction.

[0077] The materials, shapes, spacing, and overlapping lengths of the first waveguide 241 and the second waveguide 242 can be determined using the remaining descriptions of the first waveguide 141 and the second waveguide 142 described above.

[0078] The coupling waveguide 240 may be applied to the coupling devices 100, 101, 102, and 103 described above, and may be provided, for example, in place of or together with the coupling waveguides 140, 150, and 170.

[0079] Figure 10 is a flowchart illustrating the manufacturing method of the coupling device according to the embodiment.

[0080] A method for manufacturing a coupling device may include the steps of forming a first waveguide in a substrate having a transmission path at a constant distance from the surface of the substrate, and forming a second waveguide in a substrate having a transmission path at an irregular distance from the surface of the substrate.

[0081] The first waveguide may be manufactured using an ion implantation method, and the second waveguide may be manufactured using a laser beam irradiation method. The first and second waveguides manufactured in this manner may have the detailed shapes of the first and second waveguides described above.

[0082] An example of a manufacturing method for a coupling device is as follows:

[0083] First, prepare the substrate (S10). The substrate 110 may be made of glass material, or it may be made of various other transparent plastic materials.

[0084] The substrate may be prepared as a rectangular block, but is not limited to that. Guide pinholes, as described in Figure 1, may be pre-formed on the substrate.

[0085] Next, alignment marks may be formed on the substrate (S15), and multiple first waveguides may be formed on the substrate by lithography (S20). The step of forming alignment marks (S15) and the step of forming the first waveguides (S20) may be performed together in the same process. For example, a mask with a pattern suitable for the shape and number of alignment marks and first waveguides may be placed on the substrate, and ions may be implanted into the substrate. This changes the refractive index at the ion-implanted position on the substrate, and alignment marks and first waveguides may be formed.

[0086] Next, multiple second waveguides can be formed using a writing method (S25). For example, a method can be used in which the focus of a high-power pulsed laser is concentrated at a location in the substrate where the second waveguide is to be formed. The strong energy focused at a predetermined location in the substrate may melt the substrate material at that location, increasing its refractive index. By changing this focal position, a second waveguide having a three-dimensional transmission path can be formed.

[0087] The order of the steps for forming the first waveguide (S20) and forming the second waveguide (S25) may be reversed. In this case, the step for forming alignment marks (S10) may be performed beforehand, or it may be performed together with the step for forming the second waveguide (S25).

[0088] The lithography method for forming the first waveguide is limited to the formation of the transmission path in a planar manner on the surface, but the manufacturing speed is very fast. The writing method for forming the second waveguide allows the transmission path to be realized in various three-dimensional ways, but the process time is very long.

[0089] The coupling device according to this embodiment has a structure that can effectively distribute manufacturing processes with long process times and manufacturing processes with short process times, and can be manufactured economically in terms of time and cost.

[0090] For example, if a coupling device is configured using a lithography method to include only 50 planar first waveguides, the manufacturing time may be as short as approximately 2 minutes. However, the number of optical fibers that can be coupled to it is limited to 50.

[0091] On the other hand, when manufacturing a coupling device equipped with 100 second waveguides to be connected to 100 optical fibers using a writing method, the required time may be approximately 2.6 to 26 hours.

[0092] The coupling device according to this embodiment can manufacture 100 coupling waveguides that can be connected to 100 optical fibers in about 0.3 to 2.6 hours by combining a lithography method and a writing method.

[0093] The specific time figures mentioned above are illustrative and not limited to those exemplified.

[0094] The coupling device manufactured in this manner may be the aforementioned coupling devices 100, 101, 102, 103, or a coupling device modified therefrom.

[0095] Figure 11 schematically shows an electronic device according to an embodiment.

[0096] The electronic device 1000 may include a coupling device 1200 and optical fiber arrays 1500 and photonic integrated circuits 1600 connected to both sides of the coupling device 1200, respectively.

[0097] The coupling device 1200 may include any of the aforementioned coupling devices 100, 101, 102, and 103, or a combination thereof, or a coupling device with a modified structure. In other words, at one end of the coupling device 1200, the ends of a first waveguide manufactured by a lithography method may be arranged in a single row, and at the other end of the coupling device 1200, the ends of a second waveguide manufactured by a writing method may be arranged in multiple rows.

[0098] The optical fiber array 1500 includes multiple optical fibers, the output ends of which can be coupled to the ends arranged in multiple rows at one end of the coupling device 1200.

[0099] The photonic integrated circuit 1600 includes a plurality of photoelectric conversion elements that convert light into electrical signals, and may include planar waveguides that transmit light transmitted via the coupling device 1200 to each of the plurality of photoelectric conversion elements. These planar waveguides may be coupled to a first planar waveguide arranged in a row in the coupling device 1200.

[0100] Such electronic devices 1000 can be used for memory-to-memory communication, XPU (e.g., CPU (central processing unit), GPU (graphic processing unit), etc.)-memory communication, or XPU-to-XPU data transfer.

[0101] Figure 12 schematically shows an electronic device according to yet another embodiment.

[0102] The electronic device 1001 may be a processor unit package. The electronic device 1001 may include a circuit board 110, a photonic integrated circuit 1600 formed on the circuit board 110, a coupling device 1200, a drive circuit (EIC) 1700 for driving the photonic integrated circuit 1600, a processor 1800, and a memory 1900. The memory 1900 may be a high-bandwidth memory (HBM). The electronic device 1001 may further include an input interface, an output interface, and so on.

[0103] The coupling device 1200 includes a plurality of coupling waveguides 1210, one end 1200a of the coupling device 1200 may be connected to a photonic integrated circuit 1700, and the other end 1200b may be connected to an optical fiber array 1500. The optical fiber array 1500 includes a plurality of optical fibers 1510, the output ends of the plurality of optical fibers 150 may be arranged in two dimensions, i.e., in a plane parallel to the YZ plane, in a plurality of rows with different positions in the Z direction. The output ends thus arranged in two dimensions may be coupled to the ends of the two-dimensionally arranged coupling waveguides 1210, each corresponding to the other. The optical fiber array 1500 may also include guide pins 1530 that are coupled to guide pin holes 190 of the coupling device 1200.

[0104] The light from the optical fiber array 1500, thus input to the coupling device 1200, passes through the coupling waveguide 1210 and is transmitted to a plurality of planar waveguides provided in the photonic integrated circuit 1600, thereby becoming incident on the photoelectric conversion element. The light can be converted into an electrical signal by the photoelectric conversion element. The coupling device, the method for manufacturing the coupling device, and the electronic device including the coupling device described above have been explained with reference to embodiments shown in the drawings, but these are merely illustrative, and it will be understood by those with ordinary skill in the art that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the disclosed embodiments should be considered in a descriptive rather than restrictive manner. The scope of this specification is defined in the claims rather than the foregoing description and should be construed to include all differences within an equivalent scope. [Explanation of symbols]

[0105] 100, 101, 102, 103, 1200 Coupling device 110 circuit boards 140, 150, 170, 240, 1210 coupling waveguides 141, 171, 241 Waveguide 1 Waveguides 142, 172, 242 (Second Waveguide) 160 Third Waveguide 173 Directional coupler 180 Alignment Marks 190 Guide pinholes

Claims

1. A substrate comprising a first surface and a second surface facing each other, and a third surface located between the first surface and the second surface and connected to the first surface and the second surface, One or more coupling waveguides extending from the first surface to the second surface within the substrate, Includes, Each of the one or more coupling waveguides is A first waveguide is formed to be drawn inward from the third surface of the substrate, and includes a first end and a second end, the first end being exposed to the first surface side, and the second end being located inside the substrate, forming a transmission path in a first direction parallel to the third surface. Including a third end and a fourth end, the third end is located adjacent to the first waveguide inside the substrate, and the fourth end is exposed on the second surface side, and the third end and the fourth end are located at different distances from the third surface to the second waveguide, A coupling device, including a coupling device.

2. The coupling device according to claim 1, wherein the refractive index of the first waveguide and the refractive index of the second waveguide are different from each other.

3. The coupling device according to claim 1, wherein the difference between the refractive index of the first waveguide and the refractive index of the second waveguide is 0.003 or less.

4. So that the light traveling through the second waveguide is transmitted to the first waveguide, The coupling device according to claim 1, wherein the adjacent arrangement relationship between the first waveguide and the second waveguide is set.

5. When viewed from a second direction that is parallel to the third surface and perpendicular to the first direction, The coupling device according to claim 1, wherein the substrate is arranged such that a portion of the first waveguide and the second waveguide overlap.

6. The coupling device according to claim 5, wherein the distance in the second direction between a portion of the first waveguide and a portion of the second waveguide is 3 μm or less.

7. The coupling device according to claim 5, wherein the length over which a portion of the first waveguide and a portion of the second waveguide overlap is 0.1 mm or more and 5 mm or less.

8. When viewed from a third direction perpendicular to the aforementioned third surface, The coupling device according to claim 1, wherein the substrate is arranged such that a portion of the first waveguide and the second waveguide overlap.

9. The coupling device according to claim 1, wherein the length of the first waveguide is 50% or more of the length of the substrate in the first direction.

10. The coupling waveguide is, The coupling device according to claim 1, further comprising a directional coupler positioned parallel to the first waveguide and made of the same material as the first waveguide, between the first waveguide and the second waveguide.

11. The coupling device according to claim 10, wherein one end of the directional coupler is in contact with the third end.

12. The coupling apparatus according to claim 1, wherein the first waveguide is formed by implanting ions into the material constituting the substrate.

13. The coupling apparatus according to claim 12, wherein the second waveguide is formed by the modification of the material constituting the substrate by a laser.

14. The one or more coupling waveguides are The coupling apparatus according to claim 1, comprising a plurality of coupling waveguides having different distances from the third surface to the fourth end.

15. The coupling device according to claim 1, further comprising a third waveguide extending from the first surface to the second surface, having a constant distance from the third surface, and made of the same material as the first waveguide.

16. The coupling device according to claim 1, further comprising alignment marks formed so as to be drawn inward from the third surface to the substrate.

17. The coupling device according to claim 1, further comprising a guide pinhole formed such that the second surface side of the substrate is open.

18. The stage of preparing the circuit board, The steps include forming a first waveguide within the substrate, having a transmission path that is at a constant distance from the surface of the substrate, The steps include forming a second waveguide within the substrate, having a transmission path whose distance from the surface of the substrate is not constant, A method for manufacturing a coupling device, including the method described above.

19. The step of forming the first waveguide is performed using an ion implantation method. The method for manufacturing a coupling device according to claim 18, wherein the step of forming the second waveguide is performed using a laser beam irradiation method.

20. Coupling device and An optical fiber array connected to one end of the coupling device, An optical integrated circuit connected to the other end of the coupling device, Includes, The coupling device is A substrate comprising a first surface and a second surface facing each other, and a third surface located between the first surface and the second surface and connected to the first surface and the second surface, One or more coupling waveguides extending from the first surface to the second surface within the substrate, Includes, Each of the one or more coupling waveguides is A first waveguide is formed to be drawn inward from the third surface of the substrate, and includes a first end and a second end, the first end being exposed to the first surface side, and the second end being located inside the substrate, forming a transmission path in a first direction parallel to the third surface. Including a third end and a fourth end, the third end is located adjacent to the first waveguide inside the substrate, and the fourth end is exposed on the second surface side, and the third end and the fourth end are located at different distances from the third surface to the second waveguide, Electronic devices, including those mentioned above.

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