Two directly-modulated GalnAsP/InP micro-rings with different radii vertically-coupled on a common bus are assessed for both independent and simultaneous operation. A device area <0.12mm (exp 2) per microring allows the generation of 2 lambda- xlGb/s, WDM signals with 6nm wavelength separation. These show successful transmission over 25km of single-mode-fibre with < 0.2dB power penalty.
