Influence of reference path length on self‐heterodyne‐based Brillouin observation

Abstract

Fibre-optic distributed Brillouin sensing that utilises correlationdomain techniques often requires an optical delay fibre in the reference path to control the correlation peak order in the sensing fibre. Nonetheless, a suboptimal delay fibre length can result in decreased performance. In this work, as a first step towards clarifying the optimal delay fibre length for Brillouin correlation-domain sensing, the authors evaluate the effect of changing the delay fibre length on the Brillouin gain spectra in a full-length measurement scenario.

Fiber-tip temperature sensing probe based on standard Brillouin optical correlation-domain reflectometry with sinusoidal modulation

“…To date, no technique (except for the one we have developed) has been reported that enables low-cost temperature measurement near the tip of a commercially available optical fiber without necessitating any specialized processing. Alternatively, distributed sensing techniques capable of providing longitudinal temperature variations along the fiber have been explored, [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] but these too come with a high cost.…”

“…Brillouin-based single-end-access distributed sensors can be categorized into three types: Brillouin optical time-domain reflectometry (BOTDR), [12][13][14] Brillouin optical frequency-domain reflectometry (BOFDR), 15) and BOCDR. [16][17][18][19][20][21][22][23][24][25][26] Each technique has its own merits and demerits, and here we focus on BOCDR.…”