Twist characteristics of the ultraviolet-written long period fiber gratings (UV-LPFGs) are investigated in this paper. It was found experimentally that the resonance wavelength of the UV-LPFG shifts to short side proportional to square of the torsion rate, when it is twisted in both directions of clockwise and counter-clockwise, which is different from that of LPFGs written by CO2 lasers, but similar with that of the corrugated LPFGs. The phenomena can be explained by mechanisms of static compression in twisting and index change caused by photo-elastic effect.
© 2005 Chinese Optics Letters
(060.2310) Fiber optics and optical communications : Fiber optics
(060.2340) Fiber optics and optical communications : Fiber optics components
(060.2370) Fiber optics and optical communications : Fiber optics sensors
Zijia Zhang, Wenkang Shi, Kan Gao, and Zujie Fang, "Twist characteristics of the ultraviolet-written long-period fiber gratings," Chin. Opt. Lett. 2, 565-567 (2004)