Dynamical identification of open quantum systems

. I propose a quantum-trajectories approach to parametric identification of the effective Hamiltonian for a Markovian open quantum system, and discuss an application motivated by recent experiments in cavity quantum electrodynamics. This example illustrates a strategy for quantum parameter estimation that efficiently utilizes the information carried by correlations between measurements distributed in time. The rapidly developing theory of quantum parameter estimation (QPE) focuses on the design of optimal measurement strategies for extracting information about c-number parameters # # that characterize a given quantum system. While much progress has been made in applying QPE to the parametric identification of prepared quantum states, little or no attention has yet been paid to the problem of estimating parameters that characterize a dynamical quantum system. In this letter I consider the latter aspect of QPE within the context of quantum optics, and describe a quantum-trajectories me...