Slope-Assisted Brillouin-Based Distributed Fiber-Optic Sensing Techniques

Abstract

Brillouin-based fiber-optic sensing has been regarded as a powerful distributed measurement tool for monitoring the conditions of modern large civil and geotechnical structures, since it provides continuous environmental information (e.g., temperature and strain) along the whole fiber used for sensing applications. In the past few decades, great research efforts were devoted to improve its performance in terms of measurement range, spatial resolution, measurement speed, sensitivity, and cost-effectiveness, of which the slope-assisted measurement scheme, achieved by exploiting the linear slope of the Brillouin gain spectrum (BGS), have paved the way for dynamic distributed fiber-optic sensing. In this article, slope-assisted Brillouin-based distributed fiber-optic sensing techniques demonstrated in the past few years will be reviewed, including the slope-assisted Brillouin optical time-domain analysis/reflectometry (SA-BOTDA/SA-BOTDR), the slope-assisted Brillouin dynamic grating (BDG) sensor, and the slope-assisted Brillouin optical correlation domain analysis/reflectometry (SA-BOCDA/SA-BOCDR). Avenues for future research and development of slope-assisted Brillouin-based fiber-optic sensors are also prospected.

Proposal of compressed sensing-assisted Brillouin optical correlation-domain reflectometry for effective repetition rate enhancement

“…rillouin scattering-based distributed optical fiber sensors measure the strain and temperature over an optical fiber by utilizing the dependence of Brillouin frequency shift (BFS) on the parameters under test. [1][2][3][4][5] To detect fast-varying events and achieve real-time signal processing, numerous state-of-the-art methods have been proposed to accelerate the measurement speed in different sensors. [6][7][8][9][10][11][12] Among the various configurations, [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Brillouin optical correlation-domain reflectometry (BOCDR), which operates by light injection into a single end of a fiber under test (FUT), is one of the ideal options for high-speed operation due to its property of random accessibility.…”