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JP-7855464-B2 - Optical transceiver

JP7855464B2JP 7855464 B2JP7855464 B2JP 7855464B2JP-7855464-B2

Inventors

  • 加賀谷 修
  • 石井 宏佳

Assignees

  • ＣＩＧ Ｐｈｏｔｏｎｉｃｓ Ｊａｐａｎ株式会社

Dates

Publication Date
20260508
Application Date
20220912

Claims (12)

  1. Optical connector and Photoelectric element, The optical fiber connecting the optical connector and the photoelectric element, A metal housing having an internal space in which the optical connector, the photoelectric element, and the optical fiber are housed, and in which electromagnetic waves propagate. An attenuation structure is provided in the intermediate space through which the optical fiber passes within the aforementioned internal space to attenuate the electromagnetic wave, It has, The internal space is continuous in a first direction between the photoelectric element and the optical connector, and is surrounded by conductive surfaces in any direction perpendicular to the first direction. The damping structure is either a column structure consisting of a plurality of conductive pillars that are conductive to the conductive surface, or a plate structure consisting of a plurality of conductive plates that are conductive to the conductive surface. In the aforementioned column structure, The plurality of conductive columns extend in a second direction perpendicular to the first direction, The plurality of conductive columns are arranged at multiple points in a plan view along the second direction, The aforementioned points are located at the vertices of multiple quadrilaterals that share one side with adjacent quadrilaterals. The plurality of quadrilaterals are arranged in at least the first direction, The optical fiber passes through at least one pair of the plurality of quadrilaterals that are adjacent in the first direction. In the aforementioned plate structure, The plurality of conductive plates are arranged with their front and back surfaces facing in a third direction perpendicular to the first and second directions. The plurality of conductive plates are separated from each other in the third direction and face each other, dividing the intermediate space into a plurality of spaces arranged in the third direction. At least one of the aforementioned plurality of spaces is small in width in the third direction to the extent that it hinders the propagation of the electromagnetic wave. An optical transceiver through which the optical fiber passes over at least one of the aforementioned plurality of spaces.
  2. An optical transceiver according to claim 1, The aforementioned photoelectric element is part of a transmitting and receiving circuit that generates electromagnetic waves, An optical transceiver in which the frequency of the electromagnetic wave corresponds to the modulation rate of the digital modulation signal transmitted by the transmitting and receiving circuit.
  3. An optical transceiver according to claim 1, The internal space includes a first space in which the optical connector is housed and a second space in which the photoelectric element is housed. The aforementioned intermediate space is located between the first space and the second space and is smaller in height in the second direction than the first space and the second space, and is an optical transceiver.
  4. An optical transceiver according to claim 3, The first space and the second space are optical transceivers in which the height in the second direction is greater than half the wavelength of the electromagnetic wave.
  5. An optical transceiver according to claim 1, The aforementioned intermediate space is an optical transceiver in which the height in the second direction is less than half the wavelength of the electromagnetic wave.
  6. An optical transceiver according to claim 1, The damping structure is the column structure, The aforementioned plurality of rectangles are optical transceivers arranged in the first and third directions.
  7. An optical transceiver according to claim 6, The aforementioned multiple points are arranged in a square grid, Each of the aforementioned quadrilaterals is a rectangular optical transceiver.
  8. An optical transceiver according to claim 6, The aforementioned multiple points are arranged in a regular triangular grid, Each of the aforementioned quadrilaterals is a parallelogram excluding rectangles, An optical transceiver in which a pair of opposing sides of the parallelogram are parallel to the first direction.
  9. An optical transceiver according to any one of claims 1 to 8, An optical transceiver in which the gap between the attenuation structure and the conductive surface in the third direction is smaller than the length of one side of each of the plurality of rectangles and smaller than the spacing between the plurality of conductive plates.
  10. An optical transceiver according to any one of claims 1 to 8, The conductive surface includes a convex portion that protrudes into the intermediate space in the second direction, making it an optical transceiver.
  11. An optical transceiver according to claim 10, The aforementioned protrusion is an optical transceiver composed of a conductor attached to the conductive surface.
  12. An optical transceiver according to claim 3 or 4 , The second space further comprises a printed circuit board whose end is exposed from the metal housing, The printed circuit board is an optical transceiver equipped with an electrical connector at its end.

Description

This invention relates to an optical transceiver. Optical transceivers (optical transceiver modules) are widely used in optical fiber transmission (Patent Documents 1-4). Optical transceivers input and output optical signals via optical connectors, input and output electrical signals via electrical connectors, and convert optical and electrical signals using photoelectric elements. Japanese Patent Publication No. 2020-3797Japanese Patent Publication No. 2019-125662Japanese Patent Publication No. 2019-66675U.S. Patent Application Publication No. 2009/0015456 This is an exploded perspective view of an optical transceiver according to the first embodiment.This is a partial cross-sectional view of an optical transceiver according to the first embodiment.This is a perspective view of the conductive surface of a waveguide that simulates a metal casing.This is a perspective view of the attenuation structure and optical fiber.This is a side view of the damping structure.This is a plan view of the damping structure.This figure shows the frequency dependence of a waveguide simulating a metal enclosure.This is a perspective view of the protrusion and damping structure of a modified example of the first embodiment.This is a perspective view of a plurality of conductive columns and optical fibers of an optical transceiver according to the second embodiment.This is a plan view of multiple conductive columns and optical fibers.This figure shows the frequency dependence of a waveguide simulating a metal enclosure.This is a perspective view of the attenuation structure of an optical transceiver according to the third embodiment.This is a side view of the damping structure.This is a plan view of the damping structure.This figure shows the frequency dependence of a waveguide simulating a metal enclosure.This is an exploded perspective view of the protrusion and damping structure of a modified example of the third embodiment. The embodiments of the present invention will be described specifically and in detail below with reference to the drawings. Components denoted by the same reference numerals in all figures have the same or equivalent function, and repeated descriptions will be omitted. Note that the size of the figures does not necessarily correspond to the magnification. [First Embodiment] Figure 1 is an exploded perspective view of an optical transceiver according to the first embodiment. Optical transceivers (optical transceiver modules) for optical fiber transmission have become faster, smaller, and less expensive in recent years with the spread of broadband networks. Bit rates have increased from 100 Gbit/s to 400 Gbit/s, and 400 Gbit/s optical transceivers, such as the MSA (Multi Source Agreement) standards QSFP-DD or OSFP, are seeing reductions in case volume and the number of components. Network equipment equipped with optical transceivers is required to keep the intensity of unwanted electromagnetic radiation generated by the equipment below legally defined limits. In the United States, this limit must be 53.9 dB (μV/m) or less, as defined in the FCC Part 15 Subpart B standard (Class B standard, distance 3m, frequency range 1GHz to 40GHz). [Optical connector] Figure 2 is a partial cross-sectional view of an optical transceiver according to the first embodiment. The optical transceiver has an optical connector 10. The optical connector 10 is an MPO (Multi-Fiber Push On) connector. The main material of the optical connector 10 and the MT (Mechanically Transferable) ferrule 12 inside it is resin, so electromagnetic radiation to the outside is likely to occur. The optical connector 10 has guide pins 14. [Photoelectric element] The optical transceiver has one or more photoelectric elements 16. The photoelectric elements 16 are an optical transmitting subassembly (TOSA) 16A and an optical receiving subassembly (ROSA) 16B. The photoelectric elements 16 are part of the transmitting and receiving circuit that generates electromagnetic waves. The frequency of the electromagnetic waves corresponds to the modulation rate of the digital modulated signal transmitted by the transmitting and receiving circuit. In a 400 Gbit/s optical transceiver, an electrical serial data signal with a modulation rate of 26.56 Gbaud (more precisely 26.5625 Gbaud) is used, so unwanted electromagnetic waves with a frequency of 26.56 GHz (more precisely 26.5625 GHz) corresponding to that modulation rate are generated. The position of the photoelectric elements 16 varies depending on the circuit design. The photoelectric elements 16 are fixed by mounting brackets 18. [Optical fiber] The optical transceiver has one or more optical fibers 20. The optical fibers 20 connect the optical connector 10 and the photoelectric element 16. Preferably, the arrangement of the optical fibers 20 can be freely changed according to the position of the photoelectric element 16. [Printed circuit board] The optical transceiver has a printed circuit board 22. The printed