Experimental evidence of the inverse Faraday effect in laser-plasma interaction and a miniature magnetic bottle

Measurements of the inverse Faraday effect and of the absorption of circularly polarized laser light in plasmas are reported. The experiments were performed with a Nd:YAG with irradiances in the range ∼1014 W/cm2. The absorption of circularly polarized light was higher by 14% relative to the absorption of linear polarized light. This increase in the laser absorption may be related to the axial magnetic field created by the circularly polarized laser light. Axial magnetic fields of the order of 10 kGauss were measured at irradiances ∼1013 W/cm2 using the Faraday rotation diagnostic. At low intensities of ∼109 W/cm2, the magnetic field was obtained from the voltage signal induced through a ferrite ring in an output coil. The axial magnetic field induced by the circular polarized laser light increases linearly with the laser irradiance. A concept of hot plasma confinement in a mini magnetic bottle relying on the magnetic field generation induced by the circularly polarized laser field is described.