The same interferometric effect could be achieved using alternative configuration of TOAD based on symmetric Mach-Zehnder (SMZ) interferometer with SOA in each arm of SMZ. In this configuration the data and control signals co-propagate. Time delay between two control pulses is equal to the switching window duration, i.e. width of TDM channel in DEMUX applications. A polarization or wavelength filter is used at the output to reject the control signal and pass the switched data signals.