All Optical Switching With a Single Quantum Dot Strongly Coupled to a Photonic Crystal Cavity

We theoretically analyze the optical nonlinearity present at very low optical power in a system consisting of a quantum dot strongly coupled to a cavity, and show that this system can be used for ultralow power and high-speed all-optical switching. We also present numerical simulation results showing both the detailed temporal behavior of such switch and the time-integrated energy transmission through the cavity. We use two different approaches-a quantum optical one and a semiclassical one-to describe the system's behavior, and observe reasonable agreement between the outcomes of numerical simulations based on these two approaches.