Fixed-point attractor for chirp in nonlinear waveguide arrays

The propagation of ultrashort optical pulses in an AlGaAs waveguide array is studied using frequency-resolved optical gating measurements. In the nonlinear regime, the measurements show that the pulses at the output of the array evolve toward a set chirp value that is independent of the input chirp. Simulations reproduce the experimental results. The observations can be described as a fixed-point attractor on a chirp-intensity map.