CO_2 Laser Writing of Long-Period Fiber Gratings in Polarization-Maintaining Fiber under Tension

摘要

We demonstrate CO_2 laser writing of long-period fiber gratings (LPFGs) in a panda polarization-maintaining (PM) fiber under external tension. The transmission spectrum of the LPFGs depends on the irradiation direction of the writing beam with respect to the principal axes of the fiber. When the irradiation direction is along the fast axis of the PM fiber, the transmission spectra of the LPFG has two more rejection bands, compared to the transmission spectra of the LPFG written in the PM fiber without tension. Our results provide a better understanding of the formation of LPFGs written by CO_2 laser.