Mengqiu Fan

TL;DR: A novel distributed acoustic sensing (DAS) system based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) based on I/Q demodulation and homodyne detection using a 90° optical hybrid is demonstrated.

TL;DR: This work demonstrates the first time that distributed vibration sensing is realized over such a long distance without inserting repeaters, and the novel hybrid amplification scheme in this work can also be incorporated in other fiber-optic sensing systems for extension of sensing distance.

TL;DR: In this paper, the authors make a comprehensive study on a highly efficient half-open cavity design for high power random fiber laser (RFL) and optimize the fiber length for getting higher output power within the scheme, i.e., shorter fiber length is preferred for efficiently harvesting the first order random lasing at the open end of the cavity.

TL;DR: The FBA Φ-OTDR scheme demonstrated in this work can also be incorporated into other distributed fiber-optic sensing systems for extension of sensing distance or enhancement of sensing signal level.

TL;DR: The spectral reshaping effect introduced by Rayleigh scattering in a 50 km single mode fiber unifies the generated Brillouin comb in terms of both power level and linewidth and is able to obtain a 40 nm flat-amplitude MBRFL with wide bandwidth from 1557 nm to 1597 nm covering >500 Stokes lines.