All-optical switching in a vertical coupler space switch employing photocarrier-induced nonlinearity

Summary form only given. Nonlinear optical switches will be key devices in order to realize all-optical signal processing in order to meet increasing data speed requirements in future optical communications systems. Of various nonlinear optical effects, the photocarrier-induced band edge nonlinearity in semiconductor quantum wells has relatively large amplitude with a time constant in the 10-ps range depending on the carrier sweep-out time. It has been shown theoretically that a device based on such an effect and a vertical coupler structure can make an effective nonlinear optical switch. In the paper a new form of all-optical switch employing photocarrier-induced nonlinearity based on a vertical coupler structure, which allows high switch contrast, is reported.