Regular and chaotic behavior of multimode lasers

Results of recent numerical studies of the output characteristics of standing-wave lasers in cases of (1) large inhomogeneous line broadening dominating homogeneous line broadening and (2) purely homogeneous line broadening are presented. In dependence on such relevant parameters as homogeneous linewidth in relation to the mode spacing, inhomogeneous linewidth, and the lifetimes of the atomic levels, both regular and chaotic output characteristics were found in case (1), whereas in case (2) the behavior generally proved to be regular. This means that the laser system approaches a steady state characterized by constant amplitudes in the oscillating modes and phase locking. Besides the familiar types of amplitude-modulation and frequency-modulation phase locking, more-complex locking phenomena were also found to occur.