High-Spatial-Resolution Fast BOTDA for Dynamic Strain Measurement Based on Differential Double-Pulse and Second-Order Sideband of Modulation

Author

Yongkang Dong ; Dexin Ba ; Taofei Jiang ; Dengwang Zhou ; Hongying Zhang ; Chengyu Zhu ; Zhiwei Lu ; Hui Li ; Liang Chen ; Xiaoyi Bao

Author_Institution

Inst. of Opto-Electron., Harbin Inst. of Technol., Harbin, China

Volume

5

Issue

3

fYear

2013

fDate

Jun-13

Firstpage

2600407

Lastpage

2600407

Abstract

We demonstrate a high-spatial-resolution fast Brillouin optical time-domain analysis (BOTDA) for distributed dynamic strain measurement based on differential double-pulse and second-order sideband of modulation. The frequency-agility probe wave is obtained from the second-order sideband of the modulated light by using the microwave signal from a wideband arbitrary waveform generator (AWG), which reduces the bandwidth requirement of the AWG by half to ~ 5.5 GHz. The differential double-pulse scheme is proposed to improve the spatial resolution while keeping the capability of dynamic measurement. In experiment, a spatial resolution of 20 cm is achieved by using a 52/50 ns differential double-pulse, and the distributed vibration measurement is demonstrated over a 50-m Panda polarization-maintaining fiber observing the vibration frequency of up to 50 Hz. With only five averages, the standard deviation of the strain accuracy is measured to be 14 με.

Keywords

Brillouin spectra; distributed sensors; fibre optic sensors; microwave photonics; optical fibre polarisation; optical modulation; strain measurement; strain sensors; time-domain analysis; vibration measurement; waveform generators; AWG; Panda polarization-maintaining fiber; differential double-pulse sideband modulation; distributed dynamic strain measurement; distributed vibration measurement; dynamic measurement; frequency 5.5 GHz; frequency 50 Hz; frequency-agility probe wave; high-spatial-resolution fast BOTDA; high-spatial-resolution fast Brillouin optical time-domain analysis; light modulation; microwave signal; second-order sideband modulation; size -5 m; standard deviation; strain accuracy; vibration frequency; wideband arbitrary waveform generator; Amplitude modulation; Frequency modulation; Optical fiber sensors; Optical fibers; Probes; Brillouin optical time-domain analysis (BOTDA); dynamic measurement; high spatial resolution; strain measurement;

fLanguage

English

Journal_Title

Photonics Journal, IEEE

Publisher

ieee

ISSN

1943-0655

Type

jour

DOI

10.1109/JPHOT.2013.2267532

Filename

6541954