Mode-locked ultrashort pulses from an 8 $\mu$m wavelength semiconductor laser
Abstract
Quantum cascade lasers (QCL) have revolutionized the generation of mid-infrared light. Yet, the ultrafast carrier transport in mid-infrared QCLs has so far constituted a seemingly insurmountable obstacle for the formation of ultrashort light pulses. Here, we demonstrate that careful quantum design of the gain medium and control over the intermode beat synchronization enable transform-limited picosecond pulses from QCL frequency combs. Both an interferometric radio-frequency technique and second-order autocorrelation shed light on the pulse dynamics and confirm that mode-locked operation is achieved from threshold to rollover current. Being electrically pumped and compact, mode-locked QCLs pave the way towards monolithically integrated non-linear photonics in the molecular fingerprint region beyond 6 m wavelength.
Keywords
Cite
@article{arxiv.2003.04127,
title = {Mode-locked ultrashort pulses from an 8 $\mu$m wavelength semiconductor laser},
author = {Johannes Hillbrand and Nikola Opacak and Marco Piccardo and Harald Schneider and Gottfried Strasser and Federico Capasso and Benedikt Schwarz},
journal= {arXiv preprint arXiv:2003.04127},
year = {2021}
}