Nonlinear generation of the third harmonics of longitudinal refractive index for lower hybrid waves

Peripheral excitation of the third harmonics of the longitudinal refractive index for the almost travelling low-hybride wave (the wave field intensity near the plasma boundary has the main peak near the certain value of the longitudinal refractive index) is considered. The presence of a weak wave in the opposite direction causes plasma density modulation, that leads to harmonics generation. The possibility of opacity nonlinear barrier occurrence is shown