Nonlinear excitation of longitudinal photons and plasmons by high-power, short pulse lasers

Modulational excitation of longitudinal photons and electron Langmuir waves, as well as ion sound waves by an incoherent strong and superstrong radiation (high-power short pulse lasers, nonthermal equilibrium cosmic field radiation, etc.), in plasmas, is investigated. A simultaneous generation of longitudinal photons and plasmons is demonstrated. Furthermore, the kinetic instability is considered when low-frequency longitudinal photons are generated alone. The growth rates of these modes are obtained.