High Sensitivity Strain Sensor Based on Micro-Helix Micro Taper Long Period Fiber Grating

A high sensitivity strain sensor based on micro-helix micro taper long period fiber grating (MH-MTLPFG) is proposed and experimentally investigated. The MH-MTLPFG is fabricated by periodically tapering and micro helix structure on a standard single-mode fiber with arc discharge technology. The arrangement of micro helix taper makes the sensor have high strain sensing sensitivity. The experiment results show that the sensitivity of strain sensing is up to −3.478 pm/ \mu \varepsilon . Compared with the conventional MTLPFG sensor, the strain sensitivity is improved by about 10 times. The proposed high sensitivity strain sensor has a good potential for accurate strain measurement, due to its low cost, simple fabrication and good performance.