An all-optical and logic gate by four-wave mixing in a passive InP based microring resonator

An all-optical AND gate utilizing the four-wave mixing (FWM) effect in an InGaAsP/lnP microring resonator side-coupled to a bus waveguide is proposed and modelled. Semiconductor microring resonators have already been demonstrated as all-optical gates using two-photon absorption (TPA) as the switching mechanism. However free-carrier lifetime puts an upper limit in high-speed device applications. By using an ultra-fast non-linear process such as FWM, operation at bit rates up to 40 Gb/s is demonstrated for both non-return to zero (NRZ) and return to zero (RZ) modulation formats. The dependence of successful gate operation in terms of microring structural parameters and operating conditions is investigated.