Photon soliton due to induced Compton scattering

The induced (nonlinear) Compton interaction between a narrow incoherent photon spectrum--excited to high intensity in a population inversion medium (maser or laser)--and the surrounding plasma, gives rise to a strongly modulated kinetics: the narrow amplified line of width delta ν exhibits large amplitude relaxation oscillations, generating at each oscillation a photon soliton at the Compton-Doppler distance Δν/sub O/ >> delta ν on the red side of the line, which shifts rapidly towards lower frequencies at constant speed sigma and constant amplitude, its logarithmic spectral intensity log N(ν,t) keeping the form: log[N(ν,t)/N/sub O/] = [log(N/sub m//N/sub O/)]exp(-[(ν/sub s/-sigma t)-ν]2/2(anti Δν/sub O/)2) where N/sub O/ is the noise and N/sub m/ the maximum amplitude generated by the source at ν/sub s/ = ν/sub O/ - anti Δν/sub D/, ν/sub O/ being the pumping line frequency. Moreover this photon soliton is the basic element composing any high intensity electromagnetic spectrum in interaction with the plasma electrons via the nonlinear Compton scattering. A narrow spectrum (delta ν less than or equal to anti Δν/sub D/) transforms into one photon soliton and a broad spectrum (delta ν > anti Δν/sub D/) breaks into a set of such solitons