# US 12,222,249 B2 · Optical fiber identification and distance measurement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,222,249 B2 - Document ID: US12222249B2 - Status: Granted - Kind: B2 - Application number: 18/326,840 - Filed: 2023-05-31 - Published: 2023-10-12 - Granted: 2025-02-11 - Earliest claimed: 2019-10-28 - Assignees: Viavi Solutions Inc. - Applicants: Viavi Solutions France SAS - Inventors: Andre Champavere - Web page: https://patentgrep.com/patent/US12222249B2 ## CPC - G01K 11/32: using changes in transmittance, scattering or luminescence in optical fibres - G01D 5/35361: {using elastic backscattering to detect the measured quantity, e.g. using Rayleigh backscattering} - G01D 5/35364: {using inelastic backscattering to detect the measured quantity, e.g. using Brillouin or Raman backscattering} - G01M 11/3136: {for testing of multiple fibers} - G01M 11/3154: {Details of the opto-mechanical connection, e.g. connector or repeater} - H04B 10/071: using a reflected signal, e.g. using optical time domain reflectometers [OTDR] - G01K 11/324: using Raman scattering - G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00) - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - H04B: TRANSMISSION ## Abstract In some examples, optical fiber identification and distance measurement may include utilizing a reflectometer and optical fiber connection device that includes a Rayleigh wavelength pass filter to pass, in one direction, an optical reflectometer signal to an optical fiber. The reflectometer and optical fiber connection device may include a Raman wavelength pass filter to filter out, in another direction, Rayleigh backscattering from the optical reflectometer signal. Further, the Raman wavelength pass filter may pass, in the another direction, a Raman Anti-Stokes signal from the optical fiber. ## Claims ### Claim 1 A system comprising: a connection device comprising: a Rayleigh wavelength pass filter to pass, in one direction, an optical reflectometer signal to an optical fiber among a plurality of optical fibers; and a Raman wavelength pass filter to: pass, in another direction, a Raman Anti-Stokes signal from the optical fiber; and a fiber optic optical reflectometer connected to the connection device to: generate the optical reflectometer signal to the optical fiber via the connection device to obtain a reference measurement of the Raman Anti-Stokes signal; subsequent to obtaining the reference measurement, cause a temperature application source to apply a temperature stimulus at a specified location of the optical fiber, wherein the temperature application source is to be spatially selective in applying the temperature stimulus to the optical fiber to minimize temperature side effects on neighboring optical fibers; subsequent to the temperature stimulus being applied at the specified location of the optical fiber, generate another optical reflectometer signal to the optical fiber via the connection device to obtain a new measurement of the Raman Anti-Stokes signal; compare the reference measurement with the new measurement to detect and locate a variation in the optical fiber due to presence of the temperature stimulus at the specified location of the optical fiber; and identify, based on the located variation in the optical fiber, the optical fiber from the plurality of optical fibers. ### Claim 2 (depends on 1) The system according to claim 1, wherein the fiber optic optical reflectometer includes an optical time domain reflectometer (OTDR). ### Claim 3 (depends on 1) The system according to claim 1, wherein the fiber optic optical reflectometer includes an optical frequency domain reflectometer. ### Claim 4 (depends on 1) The system according to claim 1, wherein the Raman wavelength pass filter is to filter out, in the another direction, Rayleigh backscattering from the optical reflectometer signal. ### Claim 5 (depends on 1) The system according to claim 1, wherein the temperature application source is a remote controlled temperature application source to generate the temperature stimulus upon actuation of the remote controlled temperature application source. ### Claim 6 (depends on 1) The system according to claim 1, a wherein the temperature application source is caused to apply the temperature stimulus by heating up the specified location of the optical fiber. ### Claim 7 (depends on 1) The system according to claim 1, a wherein the temperature application source is caused to apply the temperature stimulus by cooling down the specified location of the optical fiber. ### Claim 8 (depends on 1) The system according to claim 1, wherein the fiber optic optical reflectometer is connected to a connection of the connection device to transmit the optical reflectometer signal towards the optical fiber, and wherein the optical fiber is connected to another connection of the connection device to transmit signals back to the fiber optic optical reflectometer. ### Claim 9 A system comprising: a first filter to pass, in one direction, an optical reflectometer signal to an optical fiber among a plurality of optical fibers; a second filter to pass, in another direction, a Raman signal from the optical fiber; and a fiber optic optical reflectometer connected to the first and second filters to: generate the optical reflectometer signal to the optical fiber via the first and second filters to obtain a reference measurement of the Raman signal; subsequent to obtaining the reference measurement, cause a temperature application source to apply a temperature stimulus at a specified location of the optical fiber, wherein the temperature application source is to be spatially selective in applying the temperature stimulus to the optical fiber to minimize temperature side effects on neighboring optical fibers; subsequent to the temperature stimulus being applied at the specified location of the optical fiber, generate another optical reflectometer signal to the optical fiber via the first and second filters to obtain a new measurement of the Raman signal; compare the reference measurement with the new measurement to detect and locate a variation in the optical fiber due to presence of the temperature stimulus at the specified location of the optical fiber; and identify, based on the located variation in the optical fiber, the optical fiber from the plurality of optical fibers. ### Claim 10 (depends on 9) The system according to claim 9, wherein the Raman signal includes a Raman Stokes signal. ### Claim 11 (depends on 9) The system according to claim 9, wherein the Raman signal includes a Raman Anti-Stokes signal. ### Claim 12 A method comprising: establishing a connection from an optical reflectometer to an optical fiber among a plurality of optical fibers via a connection device, wherein the connection device comprises filtering devices for controlling, in one direction, passage of an optical reflectometer signal from the optical reflectometer to the optical fiber and for controlling, in another direction, passage of a Raman signal from the optical fiber to the optical reflectometer; generating, by a processor of the optical reflectometer, the optical reflectometer signal to the optical fiber via the connection device to obtain a reference measurement of the Raman signal; subsequent to obtaining the reference measurement, causing, by the processor, a temperature application source to apply a temperature stimulus at a specified location of the optical fiber, wherein the temperature application source is to be spatially selective in applying the temperature stimulus to the optical fiber to minimize temperature side effects on neighboring optical fibers; subsequent to the temperature stimulus being applied at the specified location of the optical fiber, generating, by the processor, another optical reflectometer signal to the optical fiber via the connection device to obtain a new measurement of the Raman signal; comparing, by the processor, the reference measurement with the new measurement to detect and locate a variation in the optical fiber due to a presence of the temperature stimulus at the specified location of the optical fiber; and identifying, based on the located variation in the optical fiber, the optical fiber from the plurality of optical fibers. ### Claim 13 (depends on 12) The method according to claim 12, further comprising: identifying, based on the located variation in the optical fiber, a location of the temperature stimulus applied to the optical fiber. ### Claim 14 (depends on 12) The method according to claim 12, further comprising: determining, based on the located variation the optical fiber, a distance from one end of the optical fiber to a location of application of the temperature stimulus. ### Claim 15 (depends on 12) The method according to claim 12, wherein the filtering devices include a Rayleigh wavelength pass filter and a Raman wavelength pass filter, and the method further comprises: controlling in the one direction, by the Rayleigh wavelength pass filter, the passage of the optical reflectometer signal to the optical fiber; controlling in the another direction, by the Raman wavelength pass filter, passage of Rayleigh backscattering from the optical reflectometer signal; and controlling in the another direction, by the Raman wavelength pass filter, the passage of the Raman signal from the optical fiber. ### Claim 16 (depends on 12) The method according to claim 12, wherein the filtering devices include an optical circulator and a wavelength division multiplexing (WDM) coupling device, and the method further comprises: controlling in the one direction, by the optical circulator, the passage of the optical reflectometer signal to the optical fiber; controlling in the another direction, by the optical circulator, passage of Rayleigh backscattering from the optical reflectometer signal; and controlling in the another direction, by the wavelength division multiplexing (WDM) coupling device, the passage of the Raman signal from the optical fiber. ### Claim 17 (depends on 12) The method according to claim 12, wherein the filtering devices include a first optical circulator, a second optical circulator, and an optical filter, and the method further comprises: controlling in the one direction, by the first optical circulator, the passage of the optical reflectometer signal to the optical fiber; controlling in the another direction, by the second optical circulator, passage of Rayleigh backscattering from the optical reflectometer signal; and controlling in the another direction, by the optical filter, the passage of the Raman signal from the optical fiber. ### Claim 18 (depends on 12) The method according to claim 12, further comprising: applying the temperature stimulus to different optical fibers of the plurality of optical fibers; and identifying, based on the application of the temperature stimulus to the different optical fibers of the plurality of optical fibers, the optical fiber from the plurality of optical fibers.