TOAD having enhanced extinction ratio of the switching window

A Terahertz Optical Asymmetric Demultiplexer (TOAD) having preferably two non-linear elements (NLES) in which the extinction ratio is enhanced by saturating both NLEs when closing a switching window. A data signal input on one port of the TOAD is split onto two optical paths, each including one NLE. The optical paths converge at an output port. To start a switching window, a first control signal is input on an optical path that includes only one of the two NLEs. To close a switching window, one or more control signals are input such that both NLEs receive a control signal at a predetermined time after the first control signal is received by one of the NLEs. Only data signals passing through the first NLE during the switching window are output on the output port. Since both NLEs receive a second control signal at the same time, they decay together and thus avoid creation of unintended switching windows. Additionally, in certain embodiments of the present invention, the second control signal can be input on the data port or the output port, eliminating the need for a separate port for the second control signal as required by certain known TOADs.