Recent Advances in Brillouin Optical Correlation-Domain Reflectometry

Abstract

Distributed fiber-optic sensing based on Brillouin scattering has been extensively studied and many configurations have been developed so far. In this paper, we review the recent advances in Brillouin optical correlation-domain reflectometry (BOCDR), which is known as a unique technique with intrinsic single-end accessibility, high spatial resolution, and cost efficiency. We briefly discuss the advantages and disadvantages of BOCDR over other Brillouin-based distributed sensing techniques, and present the fundamental principle and properties of BOCDR with some special schemes for enhancing the performance. We also describe the recent development of a high-speed configuration of BOCDR (slope-assisted BOCDR), which offers a beyond-nominal-resolution detectability. The paper is summarized with some future prospects.

Recent progress in slope-assisted Brillouin optical correlation-domain reflectometry

“…In this Section, we describe some features unique to SA-BOCDR. A beyond-nominal-resolution effect [68,69], which is the ability to detect hotspots shorter than nominal spatial resolution, is one of the most interesting features, but we have already reviewed this effect in [42]. In this paper, we focus attention on other unique features, such as the measurement sensitivity dependencies on experimental conditions [70] and the trade-off relationship between strain dynamic range and spatial resolution [71].…”

“…A conventional BOCDR configuration required a longer measurement time because frequency-sweeping-based BGS observation was needed at every sensing point along the FUT, which made it difficult to perform real-time distributed measurement. To overcome this drawback, we have recently developed two frequency-sweeping-free configurations of BOCDR, called phase-detected (PD-) BOCDR [61,62] and slope-assisted (SA-) BOCDR [67]. Note that PD-BOCDR has been well reviewed in our recent paper [62].…”

“…To overcome this drawback, we have recently developed two frequency-sweeping-free configurations of BOCDR, called phase-detected (PD-) BOCDR [61,62] and slope-assisted (SA-) BOCDR [67]. Note that PD-BOCDR has been well reviewed in our recent paper [62].…”

Simultaneous Strain and Temperature Measurement Based on Chaotic Brillouin Optical Correlation-Domain Analysis in Large-Effective-Area Fibers

“…Brillouin optical correlation domain technology has been practically applied in strain monitoring of railways and bridges due to many advantages such as high spatial resolution and high sampling rate [1]. It can be mainly classified into two types: Brillouin optical correlation domain reflectometry (BOCDR) [2,3] and Brillouin optical correlation domain analysis (BOCDA) [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Compared with the BOCDR technology, the BOCDA technology is based on stimulated Brillouin scattering (SBS), making it advantageous over BOCDR for long-range monitoring applications.…”

Fiber-optic distributed measurement of polarization beat length using slope-assisted Brillouin optical correlation-domain reflectometry

“…Besides, the system completely stops operating if the FUT is broken during measurement. To overcome these drawbacks, one-end-access distributed beat length measurement was demonstrated on the basis of Brillouin optical correlation-domain reflectometry (BOCDR), [16][17][18][19][20][21][22] and a spatial resolution of 25 cm and a sampling rate of 20 Hz were obtained. 10) However, it was time-consuming to switch the system from beat length sensing mode to strain/temperature sensing mode, and vice versa.…”