Experimental and theoretical investigation of the impact of ultra-fast carrier dynamics on high-speed SOA-based all-optical switches.

The impact of ultra-fast carrier dynamics in semiconductor optical amplifiers (SOAs) on switches based on cross-gain and cross-phase modulation is analyzed theoretically and experimentally. We find that ultra-fast effects lead to additional spectral broadening, which improves the optical signal-to-noise ratio for switches based on an SOA and an optical filter. For such switches, the influence of ultra-fast effects on the so-called nonlinear patterning effect is analyzed for three filter configurations: the asymmetric Mach-Zehnder interferometer (AMZI), a band-pass filter (BPF), and a cascade of an AMZI and a BPF. We conclude that fast carrier dynamics dramatically reduces nonlinear patterning and that the successful high-speed (>100 Gb/s) demonstrations in the literature rely on these effects.