Waveguide architecture for photonic neural component with multiplexed optical signals on inter-node waveguides

Patent metadata

Field	Value
Publication number	US-10451798-B2
Application number	US-201916241522-A
Country	US
Kind code	B2
Filing date	Jan 7, 2019
Priority date	Feb 2, 2017
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

A photonic neural component including optical transmitters, optical receivers, inter-node waveguides formed on a board, multiplexers configured to multiplex input optical signals onto the inter-node waveguides, transmitting waveguides configured to receive optical signals emitted from the optical transmitters and transmit the received optical signals to the inter-node waveguides via the multiplexers, mirrors to partially reflect optical signals propagating on the inter-node waveguides, receiving waveguides configured to receive reflected optical signals produced by the mirrors and transmit the reflected optical signals to the optical receivers, and filters configured to apply weights to the reflected optical signals. The transmitting waveguides and receiving waveguides are formed on the board such that one of the transmitting waveguides and one of the receiving waveguides crosses one of the inter-node waveguides with a core of one of the crossing waveguides passing through a core or clad of the other.

First claim

What is claimed is:

1. A photonic neural component comprising:
a plurality of nodes including a corresponding plurality of optical transmitters and a corresponding plurality of optical receivers;
intra-node signal lines connecting an optical transmitter to an optical receiver at each of the plurality of nodes;
a plurality of inter-node waveguides formed on a board and connected to each of the plurality of nodes, such that each of the plurality optical transmitters and each of the plurality optical receivers are in optical communication with the plurality of inter-node waveguides with at least one transmitting waveguide corresponding to each of the plurality of optical transmitters; and
a plurality of filters corresponding to the plurality of optical receivers to apply a weight to a signal received by the plurality of optical receivers from the plurality of inter-node waveguides.

2. The photonic neural component of claim 1 , wherein:
the plurality of optical transmitters include a first optical transmitter to emit a first optical signal at a first wavelength and a second optical transmitter to emit a second optical signal at a second wavelength different from the first wavelength; and
the plurality of inter-node waveguides includes an inter-node waveguide to propagate the first optical signal at the first wavelength and the second optical signal at the second wavelength.

3. The photonic neural component of claim 1 , further including a plurality of multiplexers, each multiplexer in communication with a corresponding optical transmitter, wherein the plurality of multiplexers includes a multiplexer having an entrance mirror and a y-shaped waveguide structure connected by a first entrance arm and an exit arm to the inter-node waveguide onto which the multiplexer multiplexes the input optical signal, the entrance mirror configured to receive, as the input optical signal, an optical signal transmitted by a transmitting waveguide of the plurality of transmitting waveguides and reflect the input optical signal to produce a reflected optical signal that enters a second entrance arm of the y-shaped waveguide structure and joins an optical signal propagating on the inter-node waveguide where the second entrance arm meets the first entrance arm of the y-shaped waveguide structure.

4. The photonic neural component of claim 1 , wherein the plurality of filters includes an exchangeable filter that can be exchanged to change the weight.

5. The photonic neural component of claim 1 , wherein the plurality of filters includes a variable filter whose transparency can be varied to change the weight.

6. The photonic neural component of claim 1 , further comprising a plurality of semiconductor chips mounted on the board, each of the plurality of semiconductor chips including at least one optical transmitter or at least one optical receiver.

7. The photonic neural component of claim 1 , wherein the plurality of inter-node waveguides, the plurality of transmitting waveguides, and the plurality of receiving waveguides are made of polymer in a single layer of the board.

8. The photonic neural component of claim 1 , wherein the plurality of optical transmitters are divided into differential pairs in which a first optical transmitter of a differential pair emits a variable optical signal while a second optical transmitter of the differential pair emits a reference optical signal.

9. The photonic neural component of claim 1 , wherein:
the plurality of inter-node waveguides includes a first ring having two or more inter-node waveguides arranged as concentric loops;
the plurality of optical transmitters includes a first inner optical transmitter group having two or more optical transmitters disposed inside the first ring; and
the plurality of optical receivers includes a first inner optical receiver group having two or more optical receivers disposed inside the first ring.

10. The photonic neural component of claim 2 , further including plurality of mirrors, each mirror in optical communication between the plurality of inter-node waveguides and a corresponding optical receiver, wherein each mirror includes at least one mirror having a reflection coefficient dependent on wavelength.

11. The photonic neural component of claim 6 , wherein:
the plurality of semiconductor chips includes optical transmitter chips and optical receiver chips, each of the optical transmitter chips including one or more of the plurality of optical transmitters and each of the optical receiver chips including one or more of the plurality of optical receivers; and
the optical transmitter chips include a first optical transmitter chip whose one or more optical transmitters emit first optical signals at a first wavelength and a second optical transmitter chip whose one or more optical transmitters emit second optical signals at a second wavelength different from the first wavelength.

12. The photonic neural component of claim 6 , wherein:
each of the plurality of semiconductor chips is positioned such that the at least one optical transmitter included in a semiconductor chip or the at least one optical receiver included in the semiconductor chip faces the board;
a plurality of transmitting waveguides are connected to the plurality of optical transmitters via entry mirrors configured to redirect light from a direction perpendicular to the board to a direction parallel to the board; and
a plurality of receiving waveguides are connected to the plurality of optical receivers via exit mirrors configured to redirect the light from the direction parallel to the board to the direction perpendicular to the board.

13. The photonic neural component of claim 6 ,
wherein each of the intra-node signal lines connected to a respective optical receiver of the plurality of optical receivers and a respective optical transmitter of the plurality of optical transmitters and configured to receive an electrical signal representing a power of an optical signal received by the optical receiver and transmit the electrical signal to the optical transmitter, thereby connecting the optical receiver and the optical transmitter to form an input and an output of a neuron.

14. The photonic neural component of claim 8 , further comprising a plurality of semiconductor chips mounted on the board, each of the plurality of semiconductor chips including one or more of the differential pairs.

15. The photonic neural component of claim 9 , wherein:
a plurality of mirrors includes a first mirror group, each mirror of the first mirror group configured to partially reflect an optical signal propagating on an inter-node waveguide of the first ring to produce the reflected optical signal; and
the photonic neural component further comprises a plurality of first output waveguides formed on the board such that at least one first output waveguide crosses at least one inter-node waveguide of the first ring with a core of one of a crossing waveguide passing through a core or a clad of another crossing waveguide, each first output waveguide connected to outside the first ring and configured to receive the reflected optical signal produced by a first mirror of the first mirror group and transmit the reflected optical signal to outside the first ring.

16. The photonic neural component of claim 9 , further including:
a plurality of multiplexers including a first multiplexer group, each multiplexer of the first multiplexer group configured to multiplex the input optical signal onto an inter-node waveguide of the first ring; and
a plurality of first input waveguides formed on the board such that at le

Assignees

• IBM

Inventors

• Heroux Jean Benoit
• Takeda Seiji
• Yamane Toshiyuki

Classifications

• H04B10/801

  using optical interconnects, e.g. light coupled isolators, circuit board interconnections · CPC title

• G02B6/4215 Primary

  the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers (G02B6/4246 takes precedence) · CPC title

• G02B6/43

  Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections · CPC title

• G02B6/29364

  Cascading by a light guide path between filters or filtering operations, e.g. fibre interconnected single filter modules · CPC title

• G02B6/125

  Bends, branchings or intersections · CPC title