Highly sensitive long-period fiber-grating strain sensor with low temperature sensitivity

A long-period fiber-grating sensor with a high strain sensitivity of -7.6 pm/mu epsilon and a low temperature sensitivity of 3.91 pm/degrees C is fabricated by use of focused CO2 laser beam to carve periodic grooves on a large-mode-area photonic crystal fiber. Such a strain sensor can effectively reduce the cross-sensitivity between strain and temperature, and the temperature-induced strain error obtained is only 0.5 mu E/degrees C without using temperature compensation. (c) 2006 Optical Society of America.