Class-C semiconductor lasers with time-delayed optical feedback

Abstract

<jats:p>We perform a linear stability analysis and numerical bifurcation diagrams of a class-C laser with time-delayed optical feedback. We employ a rate equation system based on the Maxwell–Bloch equations, and study the influence of the dephasing time on the laser dynamics. We find a stabilizing effect of an intermediate dephasing time, i.e. when moving from a class-B to a class-C laser. At long dephasing times, a destabilization of the laser solution occurs by a feedback-induced unlocking of Rabi oscillations at the second laser threshold. We predict an optimum resistance to time-delayed optical feedback for dephasing times close to the photon cavity lifetime.</jats:p> <jats:p>This article is part of the theme issue ‘Nonlinear dynamics of delay systems’.</jats:p>

Stabilizing Nanolasers via Polarization Lifetime Tuning

“…5, δ ω lock also strongly depends on the polarization lifetime T 2 . A monotonous correlation of the locking range to the polarization lifetime however can not be detected here, in contrast to a single class-C laser with feedback which is stabilized by higher polarization lifetimes 12 .…”

“…normalizes the system such that the first laser threshold does not depend on the polarization lifetime T 2 , which allows for a fair comparison 12 . The pump current is denoted by p. The parameter ∆ω is the difference between the transition frequency of the two energy levels and the cavity mode.…”

“…The class-C laser equations can be reduced to class-B equations by considering the limit T 2 → 0, which mimicks the transition from a nanoscale to a mesoscale laser. By carrying out an adiabatic elimination of the polarization P and setting the derivative of the polarization to zero, we obtain the class-B laser equations 12,38…”

“…Previous works have shown that this additional degrees of freedom can have a stabilizing effect onto the dynamics in injection and feedback setups. 12,21 We want to deepen this analysis and predict optimal configurations for delay coupled nanolasers with a focus on frequency tuning and locking ranges. The nanolasers investigated here are assumed to be single mode in order to emphasize the effect of the internal timescales.…”

“…Therefore comprehensive insights on several setups as lasers with optical injection or feedback [30][31][32] and coupled laser systems 7,[33][34][35][36][37] have been gathered. For class-C lasers it was theoretically predicted that injection and feedback setups show significant differences 12,21 . Here we investigate the dynamics of two identical coupled class-C lasers.…”