DIRECT OBSERVATION OF SOLITON AND NORMAL PULSE-PROPAGATION BY SPECTRAL-DOMAIN REFLECTOMETRY

We report what are to our knowledge the first continuous observations of optical fiber solitons and nonsoliton pulses in the spectral domain . Using a novel optical time-resolved spectral reflectometer that meas ures the backscattered Light spectrum, we directly observed (with 200- m spatial resolution) the propagation of similar to 8.5-ps solitons an d nonsolitons traveling down 5-km fibers. Spectral breathing and the r ecovery of the original spectral widths are clearly seen for higher-or der solitons. Possible applications include in situ measurements of so liton parameters, fiber dispersions, and nonlinearities, experimental verifications of pulse propagation theories, and optical sensing. (C) 1996 Optical Society of America