Nonlinear Phenomena in Microphysics of Collisionless Plasmas. Application to Space and Laboratory Plasmas
J. Phys. IV France 05 (1995) C6-13-C6-18
Frequency Up-Conversion of an Intense Laser Beam Producing Gas Ionization in a CavityK. Hizanidis1, J.L. Vomvoridis1, J.T. Mendonca2 and D.J. Frantzeskakis3
1 Department of Electrical and Computer Engineering, National Technical University of Athens, 157 73 Athens, Greece
2 Department of Physics, Instituto Superior Tecnico, 1096 Lisboa Codex, Portugal
3 Department of Physics, University of Athens, 157 84 Athens, Greece
Frequency up-conversion of a laser beam causing gas ionization in a cavity is considered. A simple ionization model, based on one-photon and multi-photon processes is used. The WKB method is utilized to provide the slow evolution of the field amplitude. The analytical results thus obtained are presented and contrasted with the exact numerical results where all the time scales are present. The evolution of the wave frequency and its upshift predicted by the WKB method are in very good agreement with the numerical results. The same applies, though to a lesser degree, for the field energy loss as well.
© EDP Sciences 1995