A novel fiber-optic torsion sensor based on a CO/sub 2/-laser-induced long-period fiber grating

Abstract

In this letter, we propose and demonstrate a fiber-optic torsion sensor based on a novel long period fiber grating (LPFG) written by high-frequency CO/sub 2/ laser pulses. Such a sensor can be easily embedded into a structure and can determine both the twist rate and the twist direction simultaneously.