Spontaneous Symmetry Breaking and Nonlinear Population Inversion Grating in a Low-Q CW Laser

The recent experiments on a pulsed superfluorescence and prospects of a CW superradiant lasing in various active media, especially semiconductor heterostructures, [1] attract much attention to new coherent dynamical effects in such lasers. These effects take place in the case of very dense active medium and low-Q cavities when a photon (cavity) lifetime is much shorter than a polarization (optical dipole) lifetime of an active center. Here, on the basis of numerical modeling of the Maxwell-Bloch equations, we describe the steady and dynamic spontaneous symmetry breaking of the structure of the field, polarization and population inversion of an active medium with almost homogeneously broadened spectral line placed into a symmetric low-Q combined distributed feedback (DFB) Fabry-Perot cavity.