Abstract

The highly excited 4d′[5/2],3 state of Ar is populated via a three photon excitation by 248.44 nm light, a wavelength that is near the center of the KrF excimer range. We have measured a) its radiative lifetime, b) its collisional rate constant to a specific lower state, and c) the dependence of the ac Stark broadening of the excitation line shape upon laser intensity. Multiphoton resonances in rare gases have often been used to create coherent light in the UV or VUV. We describe the effort to create such light within a pulsed Ar molecular beam by using ≈400 mJ pulses of ≈ 10 ns width from a narrow-band (≈½ cm⁻¹) KrF laser and to detect fifth harmonic (49.69 nm, 24.95 eV) light via photoionization of He (IP = 24.58 eV).

© 1992 Optical Society of America