Femtosecond dynamics in semiconductor lasers: Dark pulse formation

Abstract

We report on an ultrafast upconversion experiment for semiconductor lasers to track their dynamic response after injection of a femtosecond optical pulse. Due to high sensitivity and improved signal-to-noise ratio, both continuous-wave emission and evolution of the recirculating femtosecond pulse can be tracked on timescales in excess of 1 ns. We show that for GaAs quantum-well semiconductor lasers the injected pulse evolves into an ultrafast 'dark pulse'.