Air-cladding-mode liquid-level sensor using a highly tilted fiber Bragg grating.
We report a liquid-level sensor based on the air-cladding-mode band of a 37.5° tilted fiber Bragg grating (TFBG). Partial immersion increases the radiative loss of this mode band, and the liquid level is retrieved from the integrated area between its fitted upper and lower spectral envelopes. The sensor exhibits a sens...