Method for phase-based photonic computing

• US 10,656,336 B1
• Filed: 11/01/2019
• Issued: 05/19/2020
• Est. Priority Date: 11/08/2018
• Status: Active Grant

• Current Assignee: Luminous Computing, Inc.
• Original Assignee: Luminous Computing, Inc.
• Inventors: Nahmias, Mitchell A.
• Primary Examiner(s): Lavarias, Arnel C
• Application Number:
  US16/672,231
• Publication Number:
  US 20200150345A1
• Time in Patent Office: 200 Days
• Field of Search: 359107, 359108, 385 1, 385 2, 385 3, 385 4, 385 8, 385 9, 385 10, 385 14, 385129, 385130, 385131, 385132, 385147
• CPC Class Codes: G02B 6/29355 Cascade arrangement of interferometers
• CPC Class Codes: G02B 6/4215 the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers G02B6/4246 takes precedence
• CPC Class Codes: G06E 3/005 using electro-optical or opto-electronic means
• CPC Class Codes: G06E 3/008 Matrix or vector computation
• CPC Class Codes: H04B 10/70 Photonic quantum communication
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems

Abstract

A system for photonic computing, preferably including an input module, computation module, and/or control module, wherein the computation module preferably includes one or more filter banks and/or detectors. A photonic filter bank system, preferably including two waveguides and a plurality of optical filters optically coupled to one or more of the waveguides. A method for photonic computing, preferably including controlling a computation module, controlling an input module, and/or receiving outputs from the computation module.

Claims

1. A method for optical computation comprising:

throughout a time period, controlling a filter bank based on a plurality of weights, comprising;

based on a first weight of the plurality, determining a first control signal;

based on a second weight of the plurality, determining a second control signal, wherein the second weight is different from the first weight;

providing the first control signal to a first optical filter of the filter bank, wherein the first optical filter is associated with a first optical characteristic; and

providing the second control signal to a second optical filter of the filter bank, wherein the second optical filter is associated with a second optical characteristic different from the first optical characteristic;

during the time period, receiving a first optical input signal at a first waveguide of the filter bank, wherein the first optical input signal comprises;

a first portion having the first optical characteristic; and

a second portion having the second optical characteristic;

during the time period, substantially concurrent with receiving the first optical input signal, receiving a second optical input signal at a second waveguide of the filter bank, wherein the second optical input signal comprises;

a third portion having the first optical characteristic; and

a fourth portion having the second optical characteristic; and

during the time period, in response to receiving the first and second optical input signals;

at the first optical filter, based on the first control signal, phase shifting the first portion by a first phase shift amount;

at the second optical filter, based on the second control signal, phase shifting the second portion by a second phase shift amount, different from the first phase shift amount;

after phase shifting the first and second portions, generating an optical output signal, comprising coupling the first optical input signal and the second optical input signal; and

outputting the optical output signal.

2. The method of claim 1, further comprising, at an optical splitter, during the time period:

receiving a combined optical input signal;

splitting the combined optical input signal into the first and second optical input signals;

providing the first optical input signal to the first waveguide; and

providing the second optical input signal to the second waveguide.

3. The method of claim 2, wherein:

the optical splitter further splits the combined optical input signal into a third optical input signal and a fourth optical input signal;

the third optical input signal comprises a fifth portion having the first optical characteristic and a sixth portion having the second optical characteristic; and

the fourth optical input signal comprises a seventh portion having the first optical characteristic and an eighth portion having the second optical characteristic;

the method further comprising;

throughout the time period, controlling a second filter bank based on a second plurality of weights, comprising;

based on a third weight of the second plurality, determining a third control signal, wherein the third weight is different from the first and second weights;

based on a fourth weight of the second plurality, determining a fourth control signal, wherein the fourth weight is different from the first, second, and third weights;

providing the third control signal to a third optical filter of the second filter bank, wherein the third optical filter is associated with the first optical characteristic; and

providing the fourth control signal to a fourth optical filter of the second filter bank, wherein the fourth optical filter is associated with the second optical characteristic;

during the time period, substantially concurrent with receiving the first and second optical input signals;

at a third waveguide of the second filter bank, receiving the third optical input signal from the optical splitter; and

at a fourth waveguide of the second filter bank, receiving the fourth optical input signal from the optical splitter;

during the time period, in response to receiving the third and fourth optical input signals;

at the third optical filter, based on the third control signal, phase shifting the fifth portion by a third phase shift amount different from the first and second phase shift amounts;

at the fourth optical filter, based on the fourth control signal, phase shifting the sixth portion by a fourth phase shift amount different from the first, second, and third phase shift amounts;

after phase shifting the fifth and sixth portions, generating a second optical output signal, comprising coupling the third optical input signal and the fourth optical input signal; and

outputting the second optical output signal.

4. The method of claim 3, further comprising:

at a first optical detector, sampling a first amplitude of the optical output signal; and

at a second optical detector, sampling a second amplitude of the second optical output signal.

5. The method of claim 1, wherein a first intensity ratio, defined by a first portion intensity divided by a third portion intensity, is substantially equal to a second intensity ratio, defined by a second portion intensity divided by a fourth portion intensity.

6. The method of claim 5, wherein the first optical input signal is substantially identical to the second optical input signal.

7. The method of claim 1, wherein:

the first optical input signal further comprises a fifth portion having a third optical characteristic different from the first and second optical characteristics;

the second optical input signal further comprises a sixth portion having the third optical characteristic;

the filter bank further comprises a third optical filter associated with the third optical characteristic;

controlling the filter bank based on the plurality of weight further comprises;

based on a third weight of the plurality, determining a third control signal; and

providing the third control signal to the third optical filter; and

the method further comprises, during the time period, in response to receiving the first and second optical input signals, before generating the optical output signal;

at the third optical filter, based on the third control signal, phase shifting the fifth portion by a third phase shift amount.

8. The method of claim 1, wherein:

the first optical input signal further comprises a fifth portion having a third optical characteristic different from the first and second optical characteristics;

the second optical input signal further comprises a sixth portion having the third optical characteristic;

the filter bank further comprises a third optical filter associated with the third optical characteristic;

controlling the filter bank based on the plurality of weight further comprises;

based on a third weight of the plurality, determining a third control signal; and

providing the third control signal to the third optical filter; and

the method further comprises, during the time period, in response to receiving the first and second optical input signals, before generating the optical output signal;

at the third optical filter, based on the third control signal, phase shifting the sixth portion by a third phase shift amount.

9. The method of claim 1, further comprising:

throughout a second time period after the time period, controlling the filter bank based on a second plurality of weights, comprising;

based on a third weight of the second plurality, determining a third control signal, wherein the third weight is different from the first and second weights;

based on a fourth weight of the second plurality, determining a fourth control signal, wherein the fourth weight is different from the first, second, and third weights;

providing the third control signal to the first optical filter; and

providing the fourth control signal to the second optical filter;

during the second time period, receiving a third optical input signal at the input waveguide, wherein the third optical input comprises;

a fifth portion having the first optical characteristic; and

a sixth portion having the second optical characteristic;

during the second time period, substantially concurrent with receiving the third optical input signal, receiving a fourth optical input signal at the second waveguide, wherein the fourth optical input signal comprises;

a seventh portion having the first optical characteristic; and

an eighth portion having the second optical characteristic; and

during the second time period, in response to receiving the third and fourth optical input signals;

at the first optical filter, based on the third control signal, phase shifting the fifth portion by a third phase shift amount different from the first and second phase shift amounts;

at the second optical filter, based on the fourth control signal, phase shifting the sixth portion by a fourth phase shift amount different from the first, second, and third phase shift amounts;

after phase shifting the fifth and sixth portions, generating a second optical output signal, comprising coupling the third optical input signal and the fourth optical input signal; and

outputting the second optical output signal.

10. The method of claim 1, wherein:

the first optical characteristic is a first optical wavelength;

the second optical characteristic is a second optical wavelength;

the first optical filter comprises a first wavelength-selective filter; and

the second optical filter comprises a second wavelength-selective filter.

11. The method of claim 10, wherein:

the first wavelength-selective filter comprises a first microresonator;

the second wavelength-selective filter comprises a second microresonator;

providing the first control signal to the first optical filter alters a first resonance wavelength of the first microresonator; and

providing the second control signal to second first optical filter alters a second resonance wavelength of the second microresonator.

12. The method of claim 1, wherein:

the first portion has a first input intensity x₁;

the second portion has a second input intensity x₂;

the optical output signal comprises;

a first output portion having the first optical characteristic, the first output portion having a first output intensity y₁; and

a second output portion having the second optical characteristic, the second output portion having a second output intensity y₂; and

x₁w₁/y₁ is substantially equal to x₂w₂/y₂, wherein w₁ represents the first weight and w₂ represents the second weight.