Stable pulsations of semiconductor lasers by optoelectronic feedback with avalanche photodiodes

Experimentally, stable pulsations of semiconductor lasers are achieved by using optoelectronic feedback via an avalanche photodiode and a coaxial delay line. The observed micro-wave spectrum yields a linewidth (–3 dB) down to 90 kHz at 1.7 GHz. The pulse width is determined to be 130 ps.