The curvature- or bend-sensing response of long-period gratings (LPGs) UV inscribed in D-shaped fiber has been investigated experimentally. Strong fiber-orientation dependence of the spectral response when such LPGs are subjected to bending at different directions has been observed and is shown to form the basis for a new class of single-device sensor with vector-sensing capability. Potential applications utilizing the linear response and unique bend-orientation characteristics of the devices are discussed.
© 2004 Optical Society of America
Donghui Zhao, Xianfeng Chen, Kaiming Zhou, Lin Zhang, Ian Bennion, William N. MacPherson, James S. Barton, and Julian D. C. Jones, "Bend Sensors with Direction Recognition Based on Long-Period Gratings Written in D-Shaped Fiber," Appl. Opt. 43, 5425-5428 (2004)