An analytical investigation of the optical mixing of two laser beams of identical frequencies in a spatially homogeneous collisionless plasma

Abstract

Two laser beams of the same frequency and intensity propagating in opposite directions are mixed in a uniform collisionless plasma.A standing longitudinal wave of wave number k0 = 2kL (kL being the wave number of one of the lasers) is excited and traps charged particles. Including trapped particle dynamics and making use of the properties of the Jacobi elliptic functions, an expression for the power P(t) and the energy. ΔU0 absorbed by the plasma electrons is derived. It is found that the power varies sinusoidally with time. Then the energy density ΔU0 is plotted as a function of the variable E10/kL, E10 being the electric field intensity of the lasers, and the validity of the results is discussed.