Fiber-optic intrinsic distributed acoustic emission sensor for large structure health monitoring

Abstract

A fiber-optic intrinsic distributed acoustic emission (AE) sensor is proposed. By measuring the time delay of two signals from two Mach-Zehnder interferometers, the location of AE can be deduced, and the corresponding sensor is experimentally verified to be feasible with a 206 m average location error in a 20 km sensing range, which shows that this proposed sensor is applicable for distributed AE sensing for large structure health monitoring, with the unique advantages of low cost, simple configuration, and long sensing range. The limitations of the proposed sensor are also discussed, and the future work is presented.

Real-time wavelength and bandwidth-independent optical integrator based on modal dispersion

“…To demonstrate the utility of the optical integrator for ultrafast optical data processing performed in real-time, we applied it to perform high-throughput optical phase reconstruction of phase-modulated signals at telecommunications bit rates. Optical phase reconstruction is critical to the performance of coherent optical communications systems and fiber-optic distributed sensing systems [13,14]. The temporal phase profile of an optical signal is typically monitored using a frequency-discriminator-based phase differentiator followed by an optical integrator.…”

An Improved Positioning Algorithm in a Long-Range Asymmetric Perimeter Security System

“…[1][2][3][4][5][6][7][8]. With the rapid development of optical fiber sensing technology, fiber security systems have been generated based on dual Mach-Zehnder interferometry (DMZI) vibration detection.…”

Fibre Bragg Grating-Based Acoustic Sensor Array for Improved Condition Monitoring of Marine Lifting Surfaces

“…[13]. Fibre optic acoustic emission sensors offer an alternative -the majority of such sensors (hydrophones) are based on fibre optic interferometry, such as using Mach-Zhender [14], Michelson [15] or FabryParot techniques [16,17]. Fibre Bragg Grating (FBG)-based methods are an excellent alternative for AE sensing applications [18] and recently, distributed feedback (DFB) fibre lasers have been used, as reported elsewhere [19].…”