Mode-locked pulses from mid-infrared Quantum Cascade Lasers
Mode-locked pulses from mid-infrared Quantum Cascade Lasers
Wang, C. Y.; Kuznetsova, L.; Gkortsas, V. M.; Diehl, L.; Kärtner, F. X.; Belkin, M. A.; Belyanin, A.; Li, X.; Ham, D.; Schneider, H.; Grant, P.; Song, C. Y.; Haffouz, S.; Wasilewski, Z. R.; Liu, H. C.; Capasso, F.
In this study, we report the unequivocal demonstration of midinfrared mode-locked pulses from quantum cascade lasers. The train of short pulses was generated by actively modulating the current and hence the gain of an edge-emitting quantum cascade laser (QCL). Pulses with duration of about 3 ps at full-width-at-half-maxima and energy of 0.5 pJ were characterized using a second-order interferometric autocorrelation technique based on a nonlinear quantum well infrared photodetector. The modelocking dynamics in the QCLs was modeled based on the Maxwell-Bloch equations in an open two-level system. Our model reproduces the overall shape of the measured autocorrelation traces and predicts that the short pulses are accompanied by substantial wings as a result of strong spatial hole burning. The range of parameters where short mode-locked pulses can be formed is found.
Keywords: Infrared and far-infrared lasers; Mode-locked lasers; Quantum cascade lasers
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Optics Express 17(2009)15, 12929-12943
DOI: 10.1364/OE.17.012929
Cited 168 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-12912