Granted Patent B2

US 12,613,276 · App. 18/662,517 · Granted Apr 28, 2026

Inventors: Wim Bogaerts (Melle, BE); Liu Yichen (Ghent, BE); Yancan Wu (Ghent, BE)

Assignees: IMEC VZW; Universiteit Gent

G01R31/31728G01J9/02G01J2009/0288

Abstract

Claims (35)

1 . An optical monitoring device comprising:

a first input configured to receive, from a first optical signal propagating in a first waveguide, a portion of the first optical signal coupled from the first waveguide into the first input of the optical monitoring device;

a second input configured to receive at least a portion of a second optical signal coupled into the second input;

a mixing unit configured to control combining of the portion of the first optical signal with the at least a portion of the second optical signal into at least one combined signal at at least one output from the mixing unit; and

at least one photodetector configured to detect the at least one combined signal by generating an electric signal dependent on an amplitude of the at least one combined signal incident onto the at least one photodetector,

wherein the optical monitoring device is further configured to apply a modulation signal in the mixing unit so as to modulate, after the portion of the first optical signal having been coupled from the first waveguide into the first input, at least one of a phase of the portion of the first optical signal, or an amplitude of the portion of the first optical signal being transferred into one of the at least one combined signal, and/or to modulate, after the at least a portion of the second optical signal having been coupled into the second input, at least one of a phase of the at least a portion of the second optical signal, or an amplitude of the at least a portion of the second optical signal being transferred into one of the at least one combined signal.

2 . The optical monitoring device according to claim 1 , wherein an amplitude of the portion of the first optical signal coupled from the first waveguide, is 20% or less than an amplitude of the first optical signal, and preferably 10% or less than the amplitude of the first optical signal.

3 . The optical monitoring device according to claim 1 , wherein the optical monitoring device is in the form of a photonic integrated circuit, PIC.

4 . The optical monitoring device according to claim 1 , configured to apply a modulation signal so as to modulate the phase of the portion of the first optical signal, wherein the mixing unit further comprises:

a phase shifting element configured to receive the portion of the first optical signal, and to modulate the phase of the portion of the first optical signal in response to the modulation signal, prior to combining of the portion of the first optical signal with the at least a portion of the second optical signal into the at least one combined signal.

5 . The optical monitoring device according to claim 1 , configured to apply a modulation signal so as to modulate the amplitude of the portion of the first optical signal, wherein the mixing unit further comprises:

a Mach-Zehnder interferometer configured to receive the portion of the first optical signal and the at least a portion of the second optical signal, and to modulate, in response to the modulation signal, the amplitude of the portion of the first optical signal being transferred into one of the at least one combined signal.

6 . The optical monitoring device according to claim 1 , wherein the at least one combined signal comprises a first combined signal and a second combined signal,

wherein the at least one output from the mixing unit comprises a first output and a second output, and

wherein the mixing unit is further configured to control combining of the portion of the first optical signal with the at least a portion of the second optical signal into the first combined signal at the first output, and into the second combined signal at the second output.

7 . The optical monitoring device according to claim 6 , wherein the at least one photodetector comprises a first photodetector and a second photodetector, and

wherein the first photodetector is configured to detect the first combined signal and the second photodetector is configured to detect the second combined signal.

8 . The optical monitoring device according to claim 7 , wherein the first photodetector and the second photodetector are combined into a balanced photodetector.

9 . The optical monitoring device according to claim 1 , wherein the modulation signal is a periodic modulation signal.

10 . The optical monitoring device according to claim 9 , wherein the modulation signal is a sinusoidal modulation signal.

11 . The optical monitoring device according to claim 1 , further comprising a processing unit configured to receive the electric signal from the at least one photodetector and to determine, from the electric signal received and the modulation signal, an amplitude of the first optical signal, an amplitude of the second optical signal, and an optical phase difference between the first optical signal and the second optical signal.

12 . A method for optical monitoring, the method comprising:

receiving, from a first optical signal propagating in a first waveguide, a portion of the first optical signal coupled from the first waveguide into a first input of an optical monitoring device;

receiving, from a second optical signal, at least a portion of the second optical signal coupled into the second input of the optical monitoring device;

controlling, by a mixing unit, combining of the portion of the first optical signal with the at least a portion of the second optical signal into at least one combined signal at at least one output from the mixing unit;

applying a modulation signal in the mixing unit so as to modulate, after the portion of the first optical signal having been coupled from the first waveguide into the first input, at least one of a phase of the portion of the first optical signal, or an amplitude of the portion of the first optical signal being transferred into one of the at least one combined signal, and/or to modulate, after the at least a portion of the second optical signal having been coupled into the second input, at least one of a phase of the at least a portion of the second optical signal, or an amplitude of the at least a portion of the second optical signal being transferred into one of the at least one combined signal; and

detecting, by at least one photodetector, the at least one combined signal by generating an electric signal dependent on an amplitude of the at least one combined signal incident onto the at least one photodetector.

13 . An optical monitoring device comprising:

a first input configured to receive a portion of a first optical signal coupled from a first waveguide into the first input;

a second input configured to receive at least a portion of a second optical signal coupled into the second input;

a mixing unit configured to control combining of the portion of the first optical signal with the at least a portion of the second optical signal into at least one combined signal at at least one output from the mixing unit;

at least one photodetector configured to detect the at least one combined signal by generating an electric signal dependent on an amplitude of the at least one combined signal incident onto the at least one photodetector,

wherein the optical monitoring device is further configured to apply a modulation signal so as to modulate at least one of a phase of the portion of the first optical signal, a coupling of the portion of the first optical signal into the first input, or an amplitude of the portion of the first optical signal being transferred into one of the at least one combined signal, and/or to modulate at least one of a phase of the at least a portion of the second optical signal, a coupling of the at least a portion of the second optical signal into the second input, or an amplitude of the at least a portion of the second optical signal being transferred into one of the at least one combined signal; and

a dynamic coupling element configured to tunably couple the portion of the first optical signal from the first waveguide such that an amplitude of the portion of the first optical signal, coupled from the first waveguide, is controllable,

wherein the optical monitoring device is further configured to apply a modulation signal to the dynamic coupling element so as to modulate the coupling of the portion of the first optical signal in response to the modulation signal.

Assignments (2)

Priority Claims (1)

Continuity (1)

References Cited (11)