Speaker
Description
The quantum cascade laser has evolved to be a compact, powerful source of coherent mid-infrared light. However, its fast gain dynamics strongly restricts the formation of ultrashort pulses. As such, the shortest pulses reported so far were limited to a few picoseconds with some hundreds of milliwatts of peak power, strongly narrowing their applicability for time-resolved and nonlinear experiments. Here, we demonstrate an approach capable of producing near-transform-limited sub-picosecond pulses with several watts of peak power. Starting from a frequency modulated phase-locked state, ultrashort pulses are generated via external pulse compression. We assess their temporal nature by means of a novel optical sampling method, coherent beatnote interferometry and interferometric autocorrelation.
