PHY 2203: Quantum Optics I

PHY2203 explores atom-photon interactions on a semi-classical treatment. How does a quantum system respond to a classical drive field? We begin by discussing why an atom driven by an optical field reduces to a dipole interaction Hamiltonian. The atom-photon problem can then be mapped onto the problem of a spin one-half electron in a magnetic field, since both are driven two-level quantum systems. We develop the Bloch equations, Rabi oscillations, and magnetic resonance. Returning to the optical regime, damping is necessary, and thus a treatment using density matrices. Dynamics of the density operator are described by the Optical Bloch Equations, with which one can understand a wide range of current experiments in AMO (atomic, molecular, and optical) physics and solid-state physics. These quantum dynamics are contrasted to classical (Lorentz-model) dynamics, such as quantum saturation. In the context of a diagonalized atom-photon Hamiltonian, we discuss inversion, dressed states and light shifts. Applications of this foundational material include electromagnetically induced transparency, slow light, dark states, and laser cooling.