جستجوی مقالات مرتبط با کلیدواژه "laser short pulse" در نشریات گروه "مکانیک"

In this paper, the method of second harmonic generation of longitudinal and transverse waves in cold, low-density and uniform non-magnetic plasma is invistigated, when a short pulse laser or lidar is propagated in the plasma medium and collision effects are considered. Also, the effect of external uniform magnetic field on the plasma is studied. The propagation of electromagnetic waves in isotropic plasma can produce odd harmonics, but magnetic field varies isotropic state and produce even harmonics. Using perturbation theory companents of electric field of first and second harmonic are calculated and the effects of successive reflections on the electric field amplitude of first and second harmonics and efficiency of reflection power of second harmonic are investigated. Also, with analysis of government equations the resulas are obtained. Finally, field amplitude of harmonics for zero and first perturbatins for different states are studied and variations of them in term o different parameters are plotted. Also, results and optimom conditions are discussed and some suggestions are offered.