Patent ID: 11920974
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A vibration distribution measurement system for measuring a distribution of a vibration applied to a sensing fiber, the system comprising:
a frequency sweep light source configured to output frequency sweep light;
an optical splitter configured to split the frequency sweep light into probe light and local light;
an optical mixer configured to mix backscattered light from the sensing fiber as signal light with the local light, the backscattered light being obtained by causing the probe light to be incident on the sensing fiber; and
an analysis unit comprising a processor, the analysis unit configured to analyze a beat signal obtained from output light of the optical mixer,
wherein the analysis unit estimates a distance offset from a measurement result obtained from a distribution waveform of the beat signal by measuring the beat signal at a measurement time sufficiently shorter than a cycle of the vibration at the sensing fiber, and measures a distribution of a vibration at any position by using the distance offset
wherein the distribution waveform is an electric field waveform at each distortion measurement interval defined from a light incident end and obtained by Fourier transforming the beat signal from the sensing fiber.