A chirped long period fiber grating sensor based on micro-helix taper

A sensor based on micro-helix taper chirped long period fiber grating (MHT-CLPG) is proposed and experimentally demonstrated. The MHT-CLPG is fabricated by periodically tapering and twisting a standard single-mode fiber (SMF) using arc discharge technology. A chirped structure is prepared with gradual increasing the distance between two adjacent microtapers. The measured results show that the MHT-CLPG can realize highly sensitive torsion, axial strain and bending measurements (-0.1575 nm/(rad/m), −0.006846 nm/με and −10.62 nm/m−1). The proposed sensor has a good potential for torsion, axial strain and bending measurement due to low cost, simple fabrication, high extinction ratio and good performance.