Polarization Dynamics of Vertical-Cavity Surface-Emitting Lasers (VCSELs) subject to parallel optical injection

Abstract

ABSTRACT: In this work, we investigate the polarization dynamics of vertical-cavity surface-emitting lasers (VCSELs) subject to parallel optical injection. We investigate theoretically and experimentally the polarization switching found in a transverse mode VCSEL subject to parallel optical injection. More specifically we focus on a recently found state of simultaneous injection locking of the parallel polarization and excitation of the orthogonal polarization of the solitary device, termed IL+PS. Simple mathematical expressions resulting from the spin-flip model and describing this state are found. Numerical simulations of the spin-flip model and stability analysis of the steady state describing the IL+PS state are performed to identify the region of the injected power-frequency detuning plane where this solution is stable. Experimental mapping of this region is presented. Bistability induced by power variation of the master laser is also studied, numerically, theoretically and experimentally. Very good agreement is found, both qualitatively and quantitatively. We present an experimental mapping of the non-linear dynamics of the VCSEL subject to parallel optical injection. States that have been widely explored and studied are found, along with new states of simultaneous non-linear excitation of both polarizations. Fixed points in both polarizations (IL+PS), limit cycle in both polarizations, period doubling in both polarizations, chaotic behaviour in both polarizations are observed and mapped for several bias currents. We also find behaviours resulting from an aperiodic switching between two stable non-linear states. Finally, we explore the hopping dynamics found in the VCSEL when subject to parallel optical injection. These hopping dynamics present heavy tails residence time distributions, and a spectral analysis shows a 1/f noise hopping mechanism. Work on this subject is still in progress.