레이저와 프라즈마와의 비선형상오작용에 관한 연구 -분광법에 의한 제 2고주파와 Brillouin 산람광의 검출-

Study on the Nonlinear Interaction of Laser with Plasma -Detection of Second Harmonic Light and Brillouin Scattering Light by Means of Spectroscopic Technique-

The spectra of scattering light fromlaser-produced plasma near its fundamental and second harmonic wavelength were observed respectively by means of spectroscopic technique. The experimental results and the generation mechanism of nonlinear effects such as the second garmonics and the brillouin scattering were analysed theoretically. The spectra of reflected laser light became wider than that of incident laser light. And the peak of spectrum of reflected light shifted to red-side from that of incident light. The second harmonic light is generated from the nonlinear interaction of the incident laser light and the electron plasma wave excited in resonance region by the oblique incidence of laser light to the plasma. The Brillouin backscattering from laser-produced plasmas of hydrogen and deuterium has shown an isotope effect in the red-side region of the generated second harmonic light. This isotope shift is explained by the parametric instability at the cutoff (resonance) region using frequency-and phase-matching conditions of the waves.