Fully monolithic 18.7GHz 16Ps GaAs mode-locked oscillators

We report a mode-locked electrical oscillator fully integrated in GaAs. It self generates a periodic train of pulses with a 16-ps pulse width and a 18.7-GHz frequency. This is the fastest electrical mode-locked oscillator to date, and the first integration of reflective mode-locked electrical oscillator. It works by sending a pulse back and forth on a coplanar waveguide with reflections at both ends. The reflection occurs with level-dependent gain that enables pulse formation and stabilization.