Abstract

Understanding the nonlinear interactions of multiple frequencies in optical fiber is of interest because of its relevance to wavelength division multiplexing. We consider the copropagation of two pump pulses at frequencies ω₁ and ω₂ down a single-mode polarization maintaining a fiber. At sufficiently high intensities the two lasers will interact by four-wave mixing (FWM) to produce symmetric pairs of sidebands at ω₁ - ω₂ and 2ω₂ - ω₁. This process can continue to produce cascading pairs of sidebands. We develop a theoretical framework describing the interaction of six frequencies (the two pump lasers and two pairs of FWM sidebands) by seven different FWM processes. Numerical studies demonstrate the possibility for periodic and chaotic energy exchange between the six waves as they propagate in the fiber. This chaotic energy exchange is probed both numerically and experimentally by studying the statistical properties of the first pair of sidebands in conditions where the model predicts periodic behavior and where the model predicts chaos.

© 1991 Optical Society of America