Response of TOADs to Frequency Detuned Control and Signal Picosecond Pulses

The optical switch known as the Terahertz Optical Asymmetric Demultiplexers (TOADs) is currently attracting a high degree of interest because of several key developments and new applications such as all-optical regenerative memory. However, rather little theoretical analysis of the operating characteristics of TOADs has been undertaken. Recently analysis which took into account the usual gain saturation and ultrafast intraband processes contributing to nonlinear gain compression, showed that threshold energy of TOADs can be decreased to less than 0.1pJ by matching the width of control pulse and switching window [1], and also that switching windows less than 1ps cannot be achieved in practice due to the effect of ultrafast intraband processes [2].