We present experimental results of coupled optoelectronic oscillators (COEO
) constructed with a semiconductor optical amplifier-based ring laser and a
semiconductor colliding pulse mode-locked laser. Each COEO can simultaneou
sly generate short optical pulses and spectrally pure radio frequency (RF)
signals. With these devices, we obtained optical pulses as short as 6.2 ps
and RF signals as high, infrequency, as 18.2 GHz with a spectral purity com
parable with an HP83731B synthesizer. These experiments demonstrate that CO
EO's are promising compact sources for generating low jitter optical pulses
and low phase noise RF/millimeter wave signals.