Maxwell–Bloch equations

Summary

The Maxwell–Bloch equations couple the classical electromagnetic field, governed by Maxwell's equations, to a medium of two-level quantum systems, governed by the optical Bloch equations. The field drives the atoms, and the induced atomic polarization density is the source of the field. They are the basic semiclassical model of the laser and of coherent light–matter effects such as self-induced transparency. For a single-mode laser, Haken showed that they are equivalent to the Lorenz equations, so a laser can behave chaotically.