Three-frequency Chaos in an External Cavity Injection Laser

Abstract
We report fixed-frequency interactions in a modulated delay system. In particular, we have observed frequency locking, quasiperiodicity and the progression to a chaotic state by the collapse of a three-frequency quasiperiodic attractor, characteristic of the Ruelle-Takens-Newhouse scenario, in a modulated two-sided external cavity injection laser. While the temporal and spectral characteristics of the laser emission suggest that the laser has progressed to a chaotic state, dimensionality testing of the laser output is inconclusive.