Polychromatic Cherenkov radiation and supercontinuum in tapered optical fibers

摘要

We numerically demonstrate that bright solitons in tapered optical fibers can emit polychromatic Cherenkov radiation providing they remain spectrally close to the zero dispersion wavelength during propagation along the fiber. The prime role in this phenomenon is played by the soliton self-frequency shift driving efficiency of the radiation and tuning of its frequency. Depending on tapering and input pulse power, the radiation is emitted either as a train of pulses at different frequencies or as a single temporally broad and strongly chirped pulse.