optical-bloch

Numerically integrates the optical-Bloch equations using fourth-order Runge-Kutta (RK4). The optical bloch equations are the equations of motion for the density matrix of a quantum two-level system interacting with an oscillating electric field. They are useful as a first-order approximation for many nonlinear-optical systems, but ignore the many-body physics present in semiconductors (which is fortunate, or I would be out of a job ;) ).