Temperature measurement system and method using optical signal transmission through an optical interferometer

Patent metadata

Field	Value
Publication number	US-2021381908-A1
Application number	US-202117338454-A
Country	US
Kind code	A1
Filing date	Jun 3, 2021
Priority date	Jun 3, 2020
Publication date	Dec 9, 2021
Grant date	—

Abstract

A temperature measurement technology includes generating an input optical signal at a wavelength using an optical signal generator, splitting the input optical signal into a first beam and a second beam, optically transmitting the first beam through the first arm of an interferometer, transmitting the second beam through a second arm of the interferometer that introduces a phase shift in the second beam relative to the first beam, combining at least a portion of the transmitted first beam and the transmitted phase-shifted second beam to produce an output optical signal, measuring an optical signal intensity of the output optical signal, and correlating the measured optical signal intensity with a temperature to produce a measured temperature. Alternatively, the input optical signal may be transmitted through two or more interferometers.

First claim

1 . A temperature measurement system on a chip, comprising:
an optical signal generator configured to generate an input optical signal at a predetermined wavelength; an interferometer that includes:
a beam splitter coupled to the optical signal generator, wherein the beam splitter is configured to receive the input optical signal from the optical signal generator and split the input optical signal into a first beam and a second beam;
a first arm coupled to the beam splitter to receive and optically transmit the first beam;
a second arm coupled to the beam splitter to receive and optically transmit the second beam, wherein the second arm introduces a phase shift in the second beam relative to the first beam to produce a phase-shifted second beam; and
a beam combiner coupled to the first arm and the second arm, wherein the beam combiner is configured to receive the first beam and the phase-shifted second beam and combine at least a portion of the first beam and the phase-shifted second beam to produce an output optical signal;
an optical signal detector coupled to the beam combiner, wherein the optical signal detector is configured to measure an optical signal intensity of the output optical signal and produce a measured optical signal intensity of the interferometer; and a processor coupled to the optical signal detector, wherein the processor is configured to correlate the measured optical signal intensity of the interferometer with a temperature.

2 . The temperature measurement system according to claim 1 , wherein the interferometer includes a first waveguide that forms the first arm and a second waveguide that forms the second arm, and wherein the second waveguide provides an optical transmission path for the second beam that is longer than an optical transmission path provided by the first waveguide for the first beam.

3 . The temperature measurement system according to claim 1 , wherein the processor is configured to correlate the measured optical signal intensity of the interferometer with the temperature according to a characteristic curve that relates the measured optical signal intensity of the interferometer to the temperature.

4 . The temperature measurement system according to claim 3 , wherein the characteristic curve is represented by a look-up table, and the processor is configured to correlate the measured optical signal intensity of the interferometer with the temperature by using the measured optical signal intensity as an index to the look-up table to determine the temperature.

5 . The temperature measurement system according to claim 3 , wherein the characteristic curve is represented by a mathematical function, and the processor is configured to correlate the measured optical signal intensity of the interferometer with the temperature by calculating the temperature according to the mathematical function using the measured optical signal intensity.

6 . The temperature measurement system according to claim 1 , wherein the interferometer is a first interferometer that produces an output optical signal at a measured first optical signal intensity of the first interferometer,
the temperature measurement system further comprising a second interferometer that includes a first arm configured to receive and optically transmit a portion of the input optical signal as a first beam, and a second arm configured to receive and optically transmit a portion of the input optical signal as a second beam, wherein the second arm introduces a phase shift in the second beam relative to the first beam to produce a phase-shifted second beam of the second interferometer, and wherein the first beam and phase-shifted second beam of the second interferometer combine to produce an output optical signal; wherein an optical signal detector is configured to measure an optical signal intensity of the output optical signal of the second interferometer and produce a measured second optical signal intensity of the second interferometer; and wherein the processor is configured to receive the measured first optical signal intensity of the first interferometer and the measured second optical signal intensity of the second interferometer and correlate both the measured first and second optical signal intensities of the respective first and second interferometers with the temperature.

7 . The temperature measurement system according to claim 6 , wherein the first and second interferometers have respective characteristic curves that relate the measured first and second optical signal intensities to the temperature, and wherein the processor is configured to correlate both the measured first and second optical signal intensities of the respective first and second interferometers with the temperature according to the respective characteristic curves.

8 . The temperature measurement system according to claim 7 , wherein the characteristic curve of the second interferometer is phase-shifted relative to the characteristic curve of the first interferometer, such that for any given temperature the input optical signal transmitted through the first and second interferometers produces respective output optical signals having different measured optical signal intensities.

9 . The temperature measurement system according to claim 3 , wherein the beam combiner produces at least two output optical signals having respective characteristic curves, the temperature measurement system further comprising a phase-shifting element that introduces a phase difference between the at least two output optical signals such that, at a given temperature, the respective characteristic curves of the at least two output optical signals provide different temperature measurement sensitivity.

10 . The temperature measurement system according to claim 1 , further comprising:
a reference arm through which at least a portion of the input optical signal is transmitted to produce an output optical signal; and an optical signal detector coupled to the reference arm to receive the output optical signal and measure an optical signal intensity of the output optical signal to produce a measured optical signal intensity of the reference arm, wherein the measured optical signal intensity of the interferometer is normalized by the measured optical signal intensity of the reference arm.

11 . The temperature measurement system according to claim 10 , wherein the reference arm is coupled to receive the portion of the input optical signal separate from a coupling of the input optical signal to the interferometer.

12 . A method for measuring temperature, comprising:
providing an input optical signal at a single wavelength to an interferometer; measuring an optical signal intensity of an output optical signal of the interferometer; and determining a temperature based on a characteristic curve that relates a range of output optical signal intensities to a range of temperatures.

13 . The method for measuring temperature according to claim 12 , further comprising:
splitting the input optical signal into a first beam and a second beam; causing a temperature-dependent phase shift in the second beam relative to the first beam to produce a phase-shifted second beam; and combining at least a portion of the first beam and the phase-shifted second beam to produce the output optical signal.

14 . The method for measuring temperature according to claim 12 , wherein the interferometer is a first interferometer, the optical signal intensity is a first optical signal intensity, the characteristic curve is a first characteristic curve, and the temperature is a first temperature range, the method furth

Assignees

• Fluke Corp

Inventors

• Tadayon Mohammad Amin
• Williamson Kevin R

Classifications

• G01B9/02015

  characterised by the beam path configuration · CPC title

• G01K11/32 Primary

  using changes in transmittance, scattering or luminescence in optical fibres · CPC title

• G01K15/005

  Calibration · CPC title

• G01K11/3206 Primary

  at discrete locations in the fibre, e.g. using Bragg scattering · CPC title