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EP-4737964-A1 - OPTICAL MODULE AND COMPONENT THEREOF

EP4737964A1EP 4737964 A1EP4737964 A1EP 4737964A1EP-4737964-A1

Abstract

The present disclosure provides a component for an optical device for easily adhesively fixing a tube at an appropriate position, and an optical module having the component. A component used for a connection section between a silicon chip integrated on a device substrate and an optical fiber has a flat plate-like upper section, and a first lateral section and a second lateral section that are substantially perpendicular to the upper section. The component also has a concave section that is formed by the upper section, the first lateral section, and the second lateral section, and that houses a fiber block that holds the optical fiber. In the concave section, the second lateral section has an opening for drawing out the optical fiber in an longitudinal direction. In addition, the component has a pressing section formed on the upper section and substantially perpendicular to the upper section. The pressing section is configured so that an end of a tube having a hollow section through which the optical fiber passes abuts against the pressing section.

Inventors

  • NAKANISHI TOMOHIRO
  • TANAKA KATSUYA
  • OZAWA TOSHIYUKI
  • TOMITA HIROSHI
  • YAMADA TAKASHI

Assignees

  • NTT Innovative Devices Corporation
  • NTT, Inc.

Dates

Publication Date
20260506
Application Date
20240725

Claims (8)

  1. A component used for a connection section between a silicon chip integrated on a device substrate and an optical fiber, comprising: a flat plate-like upper section, and a first lateral section and a second lateral section that are substantially perpendicular to the upper section; a concave section that is formed by the upper section, the first lateral section, and the second lateral section, with the second lateral section having an opening; and a pressing section that is formed on the upper section inside the concave section and that is substantially perpendicular to the upper section, and that is formed at a position facing the opening.
  2. The component according to claim 1, further comprising: a tube having a hollow section which the optical fiber passes through that is placed in the opening, wherein: the pressing section is formed at a position at which the pressing section abuts against a part of the tube and does not come into contact with the optical fiber.
  3. The component according to claim 2, wherein: the pressing section is formed so as to abut against a part of the tube at a single point.
  4. The component according to claim 2, wherein: the pressing section is formed so as to abut against a part of the tube at at two points.
  5. The component according to claim 4, wherein: the pressing section that abuts against the part of the tube at the at two points is connected to the upper section side.
  6. The component according to claim 2, further comprising: an adhesive housing section formed between the pressing section and the opening.
  7. The component according to claim 6, wherein: the adhesive housing section is formed by cutting further than a face where the pressing section is formed.
  8. An optical module, comprising: the component according to any one of claims 1 to 7, the device substrate, and a waveguide formed on a surface of the silicon chip, wherein: the waveguide and the optical fiber are optically coupled at an end face of the silicon chip.

Description

Technical Field The present disclosure relates to an optical module, and more particularly relates to a component used for a connection section between an optical device and an optical fiber, and an optical module that includes the component. Background Art Conventionally, there has been a demand to reduce the size and power consumption and increase the transmission speeds of optical transceiver modules within networks. There are increasing expectations that a coherent optical subassembly (COSA) which integrates an optical transmission circuit or an optical reception circuit onto a small silicon chip and co-packages this with an electronic circuit such as an amplifier can be used as a device that achieves these goals. Figure 1 shows a conventional COSA 100. Figure 1(a) is a perspective view from the top surface direction, Figure 1(b) is a perspective view from the underside direction, Figure 1(c) is a perspective view from the underside direction of an input/output section of the COSA 100, and Figure 1(d) is a cross-sectional view of the input/output section of the COSA 100 taken along a section line Id-Id. Note that, a BGA (ball grid array) side of a device substrate 10 constituting the COSA 100 is referred to as the underside. As illustrated in Figure 1, the COSA 100 has a device substrate 10 on which a silicon chip 23 including a waveguide is integrated utilizing silicon photonics technology, and a lid 30 that protects these components. In Figure 1, an optical fiber 20 that is optically connected to the waveguide formed on the surface of the silicon chip 23 is illustrated. Note that, the silicon chip 23 is integrated so that the surface on which the waveguide is formed faces the underside of the device substrate 10. A fiber block 21 is directly fixed to the silicon chip 23 so that the optical fiber 20 connects to the waveguide of the silicon chip 23 via the fiber block 21. As illustrated in Figure 1(d), there is a slight gap between the fiber block 21 and the lid 30, and the fiber block 21 does not come into contact with the lid 30. In Figure 1, the optical fiber 20 is shown as a fiber ribbon in which a plurality of optical fibers are aligned. The tips of the respective core wires of the optical fiber 20 are aligned along a V-groove of the fiber block 21. In Figure 1, a fiber protection resin 24 that is arranged opposite the V-groove of the fiber block 21 is also shown. The optical fiber 20 is fixed between the V-groove and the fiber protection resin 24. The tip of each core wire extends through the V-groove to an end face of the fiber block 21. An end face of the silicon chip 23 and an end face of the fiber block 21 are connected and fixed opposing each other. Note that, in order to prevent reflection at the end face of the silicon chip 23, the orientation of the waveguide in the vicinity of the end face of the silicon chip 23 is such that the waveguide does not become perpendicular to the end face (is not oriented in the X direction). The longitudinal direction of the optical fiber 20 is also arranged so as not to be perpendicular to the end face of the silicon chip 23. The lid 30 illustrated in Figure 1 has an optical fiber coupling section protective section 31 for protecting the coupling section between the waveguide formed on the surface of the silicon chip 23 and the optical fiber 20. In Figure 2, a conventional optical fiber coupling section protective section 31 is illustrated. Figure 2(a) is a perspective view from the underside direction of the input/output section of the COSA 100 that is similar to Figure 1(c), Figure 2(b) is a cross-sectional view in the longitudinal direction of the optical fiber 20 taken along a section line IIb-IIb, Figure 2(c) is a plan view from the underside direction of one part of the optical fiber coupling section protective section 31, and Figure 2(d) is a cross-sectional view of one part of the optical fiber coupling section protective section 31 taken along a section line IId-IId. The optical fiber coupling section protective section 31 has a flat plate-like upper section 31a, and a lateral section 31b and a lateral section 31c that are substantially perpendicular to the upper section 31a in three directions surrounding the fiber block. As illustrated in Figure 2(a), the fiber block 21 is housed within a space formed by the upper section 31a, the lateral section 31b, and the lateral section 31c. The lateral section 31c has an opening for passing the optical fiber 20 through. The optical fiber 20 is weak against a force in a direction perpendicular to the longitudinal direction thereof. Therefore, as illustrated in Figure 2, a tube 22 is provided for protecting the optical fiber 20 so that the optical fiber 20 does not directly contact the opening. The optical fiber 20 passes through the tube 22 and is fixed to the fiber block 21. The inner diameter of the tube 22 is sufficiently larger than the sum of the diameters of the individual core wires of the optical fibe