Numerical study of Risken–Nummedal–Graham–Haken instability in mid-infrared Fabry–Pérot quantum cascade lasers

Autor: N. Vukovic, Jelena Radovanović, Dmitri L. Boiko, V. Milanović
Rok vydání: 2020
Předmět:
Zdroj: Optical and Quantum Electronics. 52
ISSN: 1572-817X
0306-8919
DOI: 10.1007/s11082-020-2210-4
Popis: We review our recent theoretical studies on multimode instabilities in Fabry–Perot cavity mid-infrared quantum cascade lasers (QCLs) caused by parametric excitation of Rabi flopping oscillations. Numerical simulations are based on the semiclassical traveling wave Maxwell–Bloch equations. QCLs with a few mm cavity without an absorber exhibit intermittent RNGH self-pulsations, while regular self-pulsations are possible in short-cavity QCLs, with the cavity length of 100 μm or smaller. However, the second threshold in short-cavity QCLs is significantly increased compared to the values for a few mm long devices. We provide here a new insight on RNGH instability via bifurcation analysis of the output waveform and studies of the recurrence period density entropy. We propose an interpretation of the broadening/narrowing of the optical spectrum of a QCL i.e. switching the RNGH instability on and off observed in experiment.
Databáze: OpenAIRE