A distributed temperature sensor based on spontaneous Brillouin scattering and employing optical pulse coding has been implemented and characterized using a direct-detection receiver. The signal-to-noise ratio (SNR) enhancement provided by coding is analyzed, along with the influence of coding in stimulated Brillouin threshold. Simplex-coding using 127 bit codeword provides up to 7 dB SNR improvement, allowing for temperature sensing over 21 km of dispersion shifted fiber with 3.1 K resolution and 40 m spatial resolution, permitting to avoid the use of optical pulse amplification.
Luc Thévenaz, Malak Mohamed Hossameldeen Omar Mohamed Galal, Suneetha Sebastian
Frédéric Courbin, Georges Meylan, Gianluca Castignani, Maurizio Martinelli, Slobodan Ilic, Yi Wang, Richard Massey, Marcello Farina