Compact carrier-injection photonic crystal switch for on-chip communications

Performances and metrics of an electro-optical wavelength switch in silicon-on- insulator technology using a 20 mum long photonic crystal directional coupler structure are theoretically studied using both electrical and finite difference time domain simulations. The possibility of photonic switching through carrier injection using a forward-biased PIN diode configuration is evaluated. It is shown that wavelength routing near lambda = 1550 nm with optical insertion loss of 1 dB and an electrical cut-off frequency of 60 MHz can be achieved with a bias voltage of 1 V and a dissipated electrical power of 700 muW. Integration of the device could be applied to active routing of light in silicon chips for the realisation of on-chip switching networks.