Figure 2

Schematic of the experimental setup for TOF-based strain sensing. (a) Local strain sensing experimental setup. (b) Remote strain sensing experimental setup. FLOM-PD, fibre-loop optical-microwave phase detector; MLL, mode-locked laser; SMF, single-mode fibre; DCF, dispersion-compensation fibre; WDM, wavelength division multiplexer; OC, optical circulator; EDFA, Erbium-doped fibre amplifier; VCO, voltage-controlled oscillator.