Distributed dynamic strain fiber optics measurement by brillouin optical time-domain reflectometry
AssigneeThe Regents of the University of California
InventorsKenichi Soga, Bo Li, Jize Yan, Linqing Luo, Yifei Yu
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Abstract
A system and method for distributed dynamic strain measurement using optical fiber that is based on Brillouin optical time-domain reflectometry (BOTDR) with stimulated Brillouin scattering (SBS). A short-time Fourier transform (STFT) is used to rebuild the Brillouin frequency shift (BFS) of the SBS scattered signal to perform the dynamic strain measurement.
Claims26
A method for performing Brillouin optical time-domain reflectometry for distributed dynamic strain measurements of a structure, the method comprising:
- applying a stimulated Brillouin scattered (SBS) signal to the structure;
- simultaneously detecting the SBS signal from the structure and a continuous-wave reference signal to produce an output signal;
- processing the output signal;
- and
- measuring a distribution of the Brillouin frequency shifts (BFS) along the structure to calculate one or more of an applied strain or temperature change on the structure.
A Brillouin optical time-domain reflectometry (BOTDR) based distributed dynamic strain sensor, comprising:
- (a) a light source and signal generator configured for applying a stimulated Brillouin scattered (SBS) signal to a structure;
- (b) a detector configured for simultaneously detecting the SBS signal from the structure and a continuous-wave reference signal to produce an output signal;
- (c) a processor for processing the output signal;
- and
- (d) a non-transitory memory storing instructions executable by the processor;
- (e) wherein said instructions, when executed by the processor, perform steps comprising:
- measuring a distribution of the Brillouin frequency shifts (BFS) along the structure;
- (ii) calculating one or more of an applied strain or temperature change on the structure from the measured BFS distribution.
An apparatus for performing Brillouin optical time-domain reflectometry for distributed dynamic strain measurements of a structure, the apparatus comprising:
- (a) a light source;
- (b) a signal generator and modulator configured for manipulating light from the light source to apply a stimulated small-gain Brillouin scattered (SBS) signal to the structure;
- (c) a detector configured for simultaneously detecting the SBS signal from the structure and a continuous-wave reference signal to produce an output signal;
- (d) a processor for processing the output signal;
- and
- (e) a non-transitory memory storing instructions executable by the processor;
- (f) wherein said instructions, when executed by the processor, perform steps comprising:
- measuring a distribution of the Brillouin frequency shifts (BFS) along the structure;
- (ii) calculating one or more of an applied strain or temperature change on the structure from the measured BFS distribution.
Dependencies are inferred from the claim text.