Fabrication and sensing characteristics of chiral long-period fiber gratings written in the single-mode fiber by CO2 laser

摘要

We demonstrated the fabrication of the chiral long-period grating (CLPG) with the helical structures by twisting conventional single-mode fibre while the fibre was exposed unilaterally by CO2 laser. The bending and surrounding refractive index characteristics of the fabricated CLPG were investigated experimentally. Experimental results show that the CLPG has high bending sensitivity of 19.336 nm/m−1 and refractive index sensitivity of 932.86 nm/RIU.