A high sensitivity fiber-optic torsion sensor based on a novel ultra long-period fiber grating

作者：Zhu T; Rao YJ^*; Mo QJ

来源：Acta Physica Sinica, 2006, 55(1): 249-253.

• optical fiber sensors
• fiber gratings
• CO2 lasers
• torsion measurement
• birefringence

A high sensitivity fiber-optic torsion sensor is described, which measures twist rate and determines twist direction simultaneously by using a novel ultra long-period fiber grating (ULPFG) with periods of up to several millimeters fabricated by high frequency CO2 laser pulses. The torsion characteristics of a ULPFG are analyzed based on the coupling theory and birefringence phenomena. The experimental results show that a higher torsion sensitivity of 0.2244nm/(rad/m)for high order resonant modes was obtained, which is four times higher than that of the long-period fiber grating Written by high frequency CO2 laser pulses. Finally, an intensity-type demodulation approach for the realization of real-time torsion measurement is proposed and demonstrated based on the edge filtering effect of the ULPFG.

• 出版日期2006-1
• 单位电子科技大学; 重庆大学