Simultaneous measurement of directional torsion and temperature by using a DC-sampled helical long-period fiber grating

A new approach based on the utilization of a DC-sampled helical long-period fiber grating (DCSHLPG), enabling the simultaneous measurement of the directional torsion and ambient temperature is proposed and demonstrated. The DCSHLPG is fabricated by specially designed CO2-Laser processing platform which supports both sapphire-tube based fiber twisting and point-by-point grating writing technique. By adopting the proposed method, the crosstalk effects between the temperature and the torsion can be well discriminated, and both the torsion amounts and the torsion direction can be measured simultaneously. Moreover, the proposed sensor has competitive sensing sensitivity and low-cost. Resolutions of the torsion and temperature obtained in this study are estimated to be 0.49 degrees at a torsion angle ranging from -360 degrees to + 360 degrees and 0.08 degrees C in a temperature ranging from 24 degrees C to 100 degrees C, respectively.

Automated summary

A new method based on DCSHLPG for simultaneous measurement of directional torsion and ambient temperature is proposed, with competitive sensing sensitivity and low-cost, achieving resolutions of 0.49 degrees for torsion and 0.08 degrees C for temperature.