VUV Fluorescence And Harmonic Generation With Intense Picosecond 248 Nm Krf* Radiation

Abstract

A picosecond 248 nm KrF* laser system producing a focal intensity of greater than 1015 W /cm2 has been used to study VUV fluorescence and harmonic generation in H2, He, Ne, Ar, Kr, and Xe.The nonlinear media were found to fall into two distinct classes: the lighter materials, H2, He, and Ne, which readily support the generation of harmonic radiation, but do not fluoresce, and the heavier materials, Ar, Kr, and Xe, which produce significant amounts of fluorescence, but in which the generation of harmonic radiation decreases rapidly with the scattering order.

Limiting cross sections for multiphoton coupling

“…Secondly, it is believed possible than an understanding of these physical interactions will provide a basis for an efficient means for the generation of stimulated emission in the X-ray range [4] by direct, highly nonlinear coupling of ultraviolet radiation to atoms and molecules. This view follows since (a) the fundamental task in the production of coherent short wavelength radiation is the controlled deposition of energy at high specific power and since (b) there is accumulating physical evidence [4,5,[9][10][11][12][13][14][15][16][17] [4,[18][19][20]. This situation stems directly from basic physical reasoning [4, 21, [4, 9, 10], a model which bears an analogy to certain atom-atom and ion-atom collisional processes [9].…”