Relative strength of second harmonic and 3/2 omega emissions from long-scale-length laser produced plasmas

Experiments were conducted on the planar slab targets of carbon, aluminum, and copper using a 1.0641- mu m laser at laser intensities varying from 2*10/sup 12/ to 1*10/sup 14/ W/cm/sup 2/. The laser had a fluorescent linewidth of 4.5 AA. Spectral profiles of parametrically modulated second-harmonic as well as 3/2 omega /sub 0/ emissions have been measured for the long-scale-length plasmas so generated. Relative strengths of these emissions with respect to peak signal intensity and spectral energy content as a function of laser intensity are graphically reported. Results are discussed on the basis of two plasmon and parametric decay instabilities.<
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