Stephen Hegarty
Tyndall National Institute, Cork,
Ireland
Quantum-dot lasers subject to external optical
perturbation
Semiconductor
quantum-dot lasers have long been proposed as sources
resistant to destabilisation under the influence of external optical
feedback,
and in the case of InAs quantum-dots grown on GaAs substrates, this has
indeed
been shown to be true, at least when operating at the 1.3 micron
telecommunications window. In this talk I will discuss two extensions
to this
experiment, where the perturbing external mirror is replaced firstly by
an
isolated master laser, and then by a non-isolated quantum-dot laser,
giving a
mutually coupled configuration. Both configurations give wide regions
of
stability in parameter space, as well as a variety of dynamical states
such as
excitable pulsing and multi-stability. I will present finally current
attempts
to understand these phenomena through rate-equation modelling.