Intensity-Dependent Propagation Characteristics of Circularly Polarized High-Power Laser Radiation in a Dense Electron Plasma

Circularly polarized laser radiation propagating in an electron plasma drives the electrons into circular orbits. This orbital motion induces a magnetic field which is either parallel or antiparallel to the laser beam. The generation of this magnetic field is known as the inverse Faraday effect. Because of this magnetic field and the relativistic change of the electron mass, the wave propagation is enhanced for high intensities in the sense that the critical plasma density increases with the laser-beam intensity. For the wavelength $\lambda =1.06\mathrm{}$ μ, corresponding to a neodymium-glass laser, the dependence of the various propagation characteristics on the brightness of the beam is examined in detail. Electron densities varying between ${10}^{20}$ and 6.6 × ${10}^{21}$ particles per ${\mathrm{cm}}^3$ and radiation intensities in the range ${10}^{17}$-${10}^{20}$ W/${\mathrm{cm}}^2$ are considered. Energy losses caused by synchrotron radiation and by electron-ion bremsstrahlung are calculated.