A tilt sensor with a compact dimension based on a long-period fiber grating.

A tilt sensor with a compact dimension based on a long-period fiber grating (LPG) is proposed and experimentally demonstrated. The LPG is fixed in a rigid Plexi-glass tubular with a slant orientation and half of the LPG is immersed into the NaCl aqueous solutions, whereas the other half is exposed in air. The tilt angle is obtained by monitoring the dip wavelength shift of the LPG, which changes gradually when the immersed length of the LPG varies with the tilt angle. Experimental results show that the average sensitivity 0.077 nm/° is achieved within the measurement range from -30° to 30° at the static measurement.