Fiber loop ring down for static ice pressure detection

We studied static ice pressure detection of hydraulic structures based on fiber loop ring down technology. Our detection system consists of a mode-locked laser, two 2 × 1 optical fiber couplers, a piece of single-mode fiber, the on-line micro-bend fiber sensor and a photo-detector. The static ice pressure was monitored based on measuring the change of the ring down time induced by external ice pressure on on-line micro-bend fiber sensor. We monitored the static ice pressure during ice growth and melting from −10 °C to 6 °C. The detection sensitivity is 0.00998/(μs·kPa). The proposed pressure sensing method has many advantages such as free from the fluctuation of the light power, simple structure, fast response and high sensitivity.