Four-wave mixing in 1.3 µm quantum-dot semiconductor optical amplifiers

The static and dynamic characteristics of four-wave mixing in quantum dot semiconductor optical amplifiers are investigated. A high chip conversion efficiency of -2 dB at 0.6 nm detuning, a low (<; 5 dB) asymmetry of up-and down-conversion and a spectral range of 15 nm in which an optical signal-to-noise ratio above 20 dB is achieved. Relaxation times different for electrons and holes, 210 fs and 70 fs, respectively are identified. Small-signal bandwidths well beyond 40 GHz, wavelength conversion up to 42.7 Gb/s at a bit-error rate (BER) of 10^-12 and open eye diagrams of a converted 50 Gb/s NRZ PRBS 2³¹-1 data signal are presented.