Long-period fiber grating sensors fabrication at high-frequency carbon dioxide laser pulses

In this work, long-period fiber grating sensors are written by using a point to point technique based on the thermal shock of focused high-frequency carbon dioxide laser pulses at several kilohertz. The thermal response of each long-period fiber grating was characterized by using a Peltier module based control system. The average sensitivity of the sensor was calculated to be ∼ 0.079 nm/°C. The used technique facilitates to obtain compact and sturdy long-period fiber gratings, with low insertion loss and low-level back reflection.