title: Distributed liquid level sensors using self-heated optical fibers for cryogenic liquid management.
abstract: We present a continuous liquid level sensing system for both room temperature and cryogenic fluids with millimeter spatial resolution. Change of in-fiber Rayleigh backscattering signal from the distinct thermal response of the heated sensing fiber in liquid and in air were interrogated and spatially resolved using the optical frequency domain reflectometry. Both electrical and optical heating techniques were investigated for cryogenic liquid applications at 4 K, 77 K, and the room temperature. The successful combination of self-heated fiber and wavelength-swept Rayleigh scattering interferometry provides, for the first time to our best knowledge, a truly distributed fuel gauge with high spatial resolution for cryogenic fuel storage, transportation, and management on ground and in space.
authors.affiliation: Department of Electrical and Computer Engineering, University of Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Wang
authors.forename: Rongzhang
authors.initials: R
authors.lastname: Chen
authors.forename: Botao
authors.initials: B
authors.lastname: Zhang
authors.forename: Yuankun
authors.initials: Y
authors.lastname: Lin
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Chen