Analysis of the characteristics of TOADs subject to frequency-detuned control and signal picosecond pulses

A detailed numerical investigation has been undertaken of the dynamic responses of semiconductor optical amplifiers (SOAs) and hence the operating characteristics of terahertz optical asymmetric demultiplexers (TOADs) devices subject to frequency-detuned picosecond control and signal pulses, taking into account both gain saturation and nonlinear gain compression in the SOA. It is shown that the output behavior of TOADs exhibits significant differences depending on whether the signal and control pulses are at higher relative frequencies (positive detuning) or lower relative frequencies (negative detuning). The analysis indicates that negative frequency detuning can be used to achieve an enhanced output power in the switched region and a reduced width of switching window. Calculations are shown to be in good agreement with available experimental results.