Influence of fast gain depletion on the dynamic response of TOAD's

The operating characteristics of the terahertz optical asymmetric demultiplexer (TOAD) devices subject to picosecond control pulses have been investigated taking into account gain saturation and nonlinear gain compression, due to carrier heating and spectral holeburning. It is shown that when the control pulse width is less than /spl sim/2 ps, fast gain depletion process appears in the time resolved gain dynamics of the SOA. The fast depletion process leads to an oscillating output power structure in the switched region. The oscillatory structure is found to persist for over 1 ps and sets a limit on the practical utilization of these devices.