Tilted fiber Bragg grating for direct liquid level sensing

Liquid level sensors using optical fibers hold particular promise as replacements for many existing sensing technologies, especially in explosive environments. Optical fiber Bragg grating (FBG) techniques attract much attention because of their ease of use. Most proposed FBG sensors are based on the conversion of weight or pressure into strain which causes a wavelength change of the Bragg wavelength. Techniques using long period fiber gratings have also been proposed for direct level measurement [1, 2]. In this work, for the first time we propose a novel direct liquid level measurement technique utilizing a tilted fiber Bragg grating (TFBG).