Unlocking megawatt-peak-power laser emission with colloidal quantum dots

Output power of a laser device critically defines the application prospects. Colloidal quantum dots (QDs) have emerged as auspicious laser media; however, the exclusively low-power emission obscures the practical deployment. Here, we resolve this challenge by designing an architecture of QD laser with unprecedented peak powers in megawatt regime. The achievement is enabled by integrating the QDs with exceptional gain metrics with a seed-amplifier laser structure. Transient spectroscopy and theoretical simulation reveal that the narrow emission linewidth and large biexciton binding energy of the QDs act synergistically to enable an enhanced gain performance with submonoexcitonic threshold and record high-saturated gain cross section. A Littman-Metcalf cavity is designed to deliver the continuously tunable laser emission, and the synchronous amplification reaches the megawatt output. The high-power QD laser exhibits high spatial coherence, linear polarization, and operational endurance, which has proved effective as the pump source for spectroscopic research.