Measurement Using A Multi-Core Optical Fiber

Patent metadata

Field	Value
Publication number	US-2016018245-A1
Application number	US-201514799586-A
Country	US
Kind code	A1
Filing date	Jul 15, 2015
Priority date	Jul 17, 2014
Publication date	Jan 21, 2016
Grant date	—

Abstract

A system receives data corresponding to light signals in the plurality of cores, the plurality of cores including a first pair of cores spaced apart laterally along a first direction in the optical fiber, and a second pair of cores spaced apart laterally along a second direction in the optical fiber. The system determines a directional measurement of a dynamic parameter based on the data corresponding to light signals in the plurality of cores, wherein directionality of the directional measurement is indicated by a difference between a response of the first pair of cores to a stimulus and a response of the second pair of cores to the stimulus.

First claim

What is claimed is:

1 . A method comprising:
receiving, by a system including a processor, data corresponding to light signals in a plurality of cores of a multi-core optical fiber, the plurality of cores including a first pair of cores spaced apart laterally along a first direction in the optical fiber, and a second pair of cores spaced apart laterally along a second direction in the optical fiber; and determining, by the system, a directional measurement of a dynamic parameter based on the data corresponding to light signals in the plurality of cores, wherein directionality of the directional measurement is indicated by a difference between a response of the first pair of cores to a stimulus and a response of the second pair of cores to the stimulus.

2 . The method of claim 1 , further comprising:
determining the response of the first pair of cores by computing a difference between a phase shift of a backscattered light signal in a first core of the first pair of cores, and a phase shift of a backscattered light signal in a second core of the first pair of cores; determining the response of the second pair of cores by computing a difference between a phase shift of a backscattered light signal in a first core of the second pair of cores, and a phase shift of a backscattered light signal in a second core of the second pair of cores.

3 . The method of claim 1 , wherein the stimulus is a directional stimulus along a given direction, the directional stimulus causing stretching deformation of a first core of the first pair of cores, and squeezing deformation of a second core of the first pair of cores.

4 . The method of claim 1 , wherein the dynamic parameter comprises one of vibration and acoustic energy.

5 . The method of claim 1 , wherein the determined directional measurement of the dynamic parameter is independent of an environment condition of an environment surrounding the multi-core optical fiber.

6 . The method of claim 1 , wherein determining the directional measurement of the dynamic parameter is based on measurements of mode coupling coefficients of the respective first and second pairs of cores, each mode coupling coefficient representing mode coupling between a respective pair of the first and second pairs of cores.

7 . The method of claim 1 , wherein determining the directional measurement of the dynamic parameter is based on measurements of propagation coefficients of a coupled mode of the respective first and second pairs of cores, the propagation coefficient representing a speed and attenuation of light propagating in a respective pair of cores in coupled mode.

8 . A system comprising:
a multi-core optical fiber including a plurality of cores; and a measurement subsystem comprising:
a first detector to utilize a first type of optical measurement technique to measure a parameter in a first of the plurality of cores, and
a second detector to utilize a second, different type of optical measurement technique to measure a parameter in a second of the plurality of cores.

9 . The system of claim 8 , wherein the first type of optical measurement technique is an optical measurement technique selected from the group consisting of a Raman backscattering technique, a Brillouin scattering technique, a coherent Rayleigh noise scattering technique, and a Fiber Bragg Grating reflection technique, and the second type of optical measurement technique is a different optical measurement technique selected from the group consisting of a Raman backscattering technique, a Brillouin scattering technique, a coherent Rayleigh noise scattering technique, and a Fiber Bragg Grating reflection technique.

10 . The system of claim 9 , wherein the measurement subsystem further comprises a third detector to utilize a third type of optical measurement technique to measure a parameter in a third of the plurality of cores, the third type of optical measurement technique different from the first and second types of optical measurement techniques.

11 . The system of claim 8 , wherein the first and second optical detectors are configured to concurrently measure multiple parameters.

12 . A system comprising:
a multi-core optical fiber including a plurality of cores; and a processing subsystem configured to:
receive data corresponding to light signals in the plurality of cores, the plurality of cores including a first pair of cores spaced apart laterally along a first direction in the optical fiber, and a second pair of cores spaced apart laterally along a second direction in the optical fiber; and
determine a directional measurement of a dynamic parameter based on the data corresponding to light signals in the plurality of cores, wherein directionality of the directional measurement is indicated by a difference between a response of the first pair of cores to a stimulus and a response of the second pair of cores to the stimulus.

13 . The system of claim 12 , wherein the multi-core optical fiber has a portion extending along a given direction, wherein the first direction is generally perpendicular to the given direction, and the second direction is generally perpendicular to the given direction, and he first direction is generally perpendicular to the second direction.

14 . The system of claim 12 , wherein the stimulus is a directional stimulus along a given direction, the directional stimulus causing stretching deformation of a first core of the first pair of cores, and squeezing deformation of a second core of the first pair of cores.

15 . The system of claim 12 , wherein the dynamic parameter comprises one of vibration and acoustic energy.

16 . The system of claim 12 , wherein the determined directional measurement of the dynamic parameter is independent of an environment condition of an environment surrounding the multi-core optical fiber.

17 . The system of claim 12 , wherein determining the directional measurement of the dynamic parameter is based on measurements of mode coupling coefficients of the respective first and second pairs of cores, each mode coupling coefficient representing mode coupling between a respective pair of the first and second pairs of cores.

18 . The system of claim 12 , wherein determining the directional measurement of the dynamic parameter is based on measurements of propagation coefficients of a coupled mode of the respective first and second pairs of cores, the propagation coefficient representing a speed and attenuation of light propagating in a respective pair of cores in coupled mode.

19 . The system of claim 12 , further comprising:
an optical connection component optically coupled to an end of the multi-core optical fiber to optically connect at least two of the plurality of cores.

20 . The system of claim 12 , further comprising a subsystem to one or both of: deliver optical power over at least one core of the plurality of cores, and perform data telemetry using optical signals communicated over at least one core of the plurality of cores.

Assignees

• Schlumberger Technology Corp

Inventors

• Yamate Tsutomu
• Kader Kamal
• Chee Soon Seong
• Ikegami Toru
• Fukuhara Masafumi
• Weerasinghe Nalin

Classifications

• G01V1/208

  having a continuous structure (detecting traffic G08G, transducers in general G10K) · CPC title

• G02B6/02042 Primary

  Multicore optical fibres · CPC title

• G01D5/35358

  using backscattering to detect the measured quantity · CPC title

• G01D5/3538

  using a particular type of fiber, e.g. fibre with several cores, PANDA fiber, fiber with an elliptic core or the like · CPC title

• G01D5/35354

  Sensor working in reflection · CPC title