Sweep free BOTDA based on DD-OOFDM channel estimation

A novel Brillouin optical time-domain analysis (BOTDA) system is demonstrated using intensity-modulated optical orthogonal frequency division multiplexing probe signal and direct detection (IM-DD-OOFDM) for stimulated Brillouin spectrum (SBS) measurement without frequency sweep operation. The SBS is reconstructed by channel estimation algorithm and Brillouin frequency shift (BFS) is located by curve fitting. The IM-DD-OOFDM BOTDA is demonstrated experimentally with 25m spatial resolution over 2 km standard single mode fiber.