Femtosecond-pulse-driven extreme-ultraviolet lasers.

摘要

This dissertation describes a novel method of producing extreme ultraviolet laser radiation in a highly ionized gaseous plasma and the design and construction of the multi-terawatt laser system required to produce the necessary plasma. By focusing a circularly polarized femtosecond laser pulse to a sufficient intensity in a gas, field-induced-tunneling ionization creates a uniform plasma of cold, highly ionized ions and energetic electrons. Subsequent collisions between electrons and ions induce excitations that result in lasing. Calculations for lasing at 48 nm in Ar IX (neon-like), 32 nm in Kr IX (nickel-like), and 42 nm in Xe IX (palladium-like) are presented. Experimentally, lasing is observed in Xe IX at 41.8 nm. At a xenon pressure of 12 torr, an estimated gain coefficient of 13.3 cm