Nonlinear Dynamics in Semiconductor Lasers - Abstract
Sciamanna, Marc
Characteristics of optical chaos from a laser diode with phase-conjugate feedback M. Sciamanna (1), E. Mercier (1), D. Wolfersberger (1) (1) OPTEL Research Group, CentraleSupélec, Université Paris-Saclay, and LMOPS Laboratory (CentraleSupélec and Université de Lorraine), 2 Rue Edouard Belin, F-57070 Metz, France Email: marc.sciamanna@centralesupelec.fr In contrast to conventional optical feedback (COF), there have been only few experiments analyzing the impact of phase-conjugate optical feedback (PCF) on a laser diode dynamics (see e.g. Refs. [1-4] and references therein). In contrast to COF, a laser diode with PCF admits only one steady-state solution which destabilizes to limit-cycle solutions of increasing frequency when increasing the feedback strength. These self-pulsating solutions have been called 'External Cavity Modes' (ECMs) because their frequency is a multiple of the external-cavity frequency. ECMs then exhibit secondary bifurcations to quasiperiodic dynamics and chaos. ECMs in the PCF laser system have only recently been evidenced experimentally [2]. We shall review here the sequence of bifurcations following which ECMs lead to optical chaos and, consequently, the properties of that chaotic dynamics. Although the chaotic dynamics at first sight resembles the low-frequency fluctuations (LFF) known in COF - i.e. successive power dropouts at randomly distributed time-intervals, a close inspection of the frequency content of that dynamics just before and after a power dropout reveals the onset of self-pulsating dynamics with increasing and multiple frequencies, which correspond in fact to destabilized ECMs from the PCF laser system. The LFF chaotic dynamics then corresponds to a chaotic itinerancy among these destabilized self-pulsating ECMs, thus confirming earlier theoretical predictions [5]. This specific feature of chaos generated from PCF explains the observed improvement of the chaos bandwidth when comparing chaos generated from PCF to chaos generated from COF for a similar feedback rate and external cavity length. Up to about 30?haos bandwidth enhancement is observed within the range of phase-conjugate mirror reflectivities that can be achieved experimentally [4]. Besides the chaos bandwidth we shall present preliminar results on other properties of the PCF-induced chaos, including chaos complexity, within the context of chaos-based applications [6] [1] J.S. Lawrence and D.M.Kane, "Contrasting conventional optical and phase-conjugate optical feedback in laser diodes. Phys. Rev. A 63, 033805 (2001). [2] A. Karsaklian dal Bosco, D. Wolfersberger, M. Sciamanna, "Super-harmonic self-pulsations from a time-delayed phase-conjugate optical system", Appl. Phys. Lett. 105, 081101 (2014) [3] A. Karsaklian dal Bosco, D. Wolfersberger, and M. Sciamanna, "Extreme events in time-delayed nonlinear optics", Opt. Lett. 38, 703 (2013). [4] E. Mercier, D. Wolfersberger, and M. Sciamanna, "High-frequency chaotic dynamics enabled by optical phase-conjugation", Sci. Rep. 6, 18988 (2016). [5] E. Mercier, D. Wolfersberger, and M. Sciamanna, "Bifurcation to chaotic low-frequency fluctuations in a laser diode with phase-conjugate feedback", Opt. Lett. 39, 4021-4024 (2015) [6] M. Sciamanna and K.A. Shore, Nat. Photonics 9, 151-162 (2015).