Free-carrier-induced high-order instability in an optical microcavity

Abstract

We investigate high-order instability caused by free-carrier dispersion in an optical microcavity by modeling the resonator as a system of coupled nonlinear delay-and-differential equations. We show that on higher-order branches of the stability curve, self-pulsation can occur over a much larger range of free-carrier lifetimes than on the first branch. We also show that free-carrier absorption has a deleterious effect on the onset of instability, making it generally more difficult to observe self-pulsation in the resonator, although its impact is less pronounced on higher-order instability compared to instability on the lowest branch. As a possible practical route to reach self-pulsation on the upper branch, we also propose a method based on linear phase tuning that does not require prohibitively large input powers.