Abstract
We demonstrate all-optical AND and NAND logic gate operations by nonlinear absorption in a single critically coupled semiconductor micro-racetrack resonator. The device is pumped with two counter-propagating data streams tuned to one of its resonance wavelengths and probed at the next higher resonance wavelength. We investigate and compare the performance of both InP and GaAs devices in terms of switching energy and speed. The GaAs gate demonstrates operation up to 30 Gb/s.