Real-time Strain Field Measurement Based on Dense Fiber Bragg Gratings Array

Real-time high spatial resolution fiber sensing is crucial for achieving high-precision strain measurement for various applications. Bulky optical frequency domain reflectometry is one of the mainstream devices capable of achieving spatial resolution at the micrometer level, but their relatively expensive tunable laser and poor real-time performance are becoming the bottlenecks to hinder the development of ultra-compact and fast response strain field measurement systems that are highly demanded in practice. Herein, we proposed a real-time and low-cost accurate strain field measurement methodology based on dense fiber Bragg gratings array with wavelength division multiplexing, in which the system showed a flexibly adjustable spatial resolution down to 10mm and ultra-high strain resolution of 0.83 με. Such strain field measurement methodology has been successfully applied to two-dimensional irregular shape sensing with a maximum relative reconstruction error of 0.16% and dynamic strain field monitoring with 50Hz sampling rate. The high-density fiber Bragg gratings array based on strain field measurement systems could have the capability of cost-effective and robust practicality.