A semiclassical theory of the laser

The kinetic equation for the density matrix is used to study the response of a laser system to a monochromatic electromagnetic standing wave. Steady-state laser operation is studied through joint solution of Maxwell's equations and the equations for the density matrix. Allowances are made for nonuniformities in the radiating medium modulated by the field and for the motion of the radiating particles. Steady-state operating conditions and oscillation thresholds for gas and solid-state lasers are compared.