Distributed multi-parameter sensing based on the Brillouin scattering effect in orbital angular momentum guiding fiber

Abstract

The orbital angular momentum (OAM) guiding fiber is used as a sensing element to measure strain and ambient temperature, sensing information simultaneously in a classical BOTDR configuration, due to its higher-order acoustic modes and high stimulated Brillouin threshold. The Brillouin threshold, the Brillouin gain coefficient and the Brillouin gain spectrum (BGS) of OAM fiber at 1.5 µm are characterized and demonstrated theoretically and experimentally. Taking advantage of the special acoustic properties of the peaks caused by the hard cladding-core interface in the Brillouin scattering process, the distributed multi-parameter sensing (e.g., strain and/or ambient temperature) is verified over a 1-km OAM guiding fiber, with the respective errors of strain and temperature of 18.2 µɛ and 0.93 °C, respectively.