Abstract
The switching scheme using four-wave mixing with two independent pumps has three inputs and four outputs. One of the inputs is chosen as the control beam. The intensity relationships among these inputs and outputs are studied by using the coupled-mode theory and boundary conditions. It is found that the output signal level is zero when the switch is off and is equal to the exact input signal level when the switch is on. The result indicates that these switching devices are ideal for cascaded use, which requires equal input and output level of the switch because the outputs of one stage will be the inputs of next stage. This property is different from those schemes using four-wave mixing with one independent pump,1 which has the output signal level different from the input signal level when the switch is on. The performance of the switching device is strongly dependent on the nonlinear factor of the interactions. The required control signal level for switching operation is lower when the nonlinear factor is large.