Laser Bandwidth and Intensity Effects in Multiphoton Ionization of Sodium

Recently there has been interest in the development of theoretical methods for incorporating the effects of finite laser bandwidth in the treatment of the ac Stark effect in the two-level atom approximation, and in the extension of this model to approximate descriptions of weak probe double resonance experiments [1]. In this paper we briefly describe some experimental observations which have played a role in motivating recent developments in the mathematical framework for treating finite laser bandwidth effects in phase diffusion models [2] and, more recently, in chaotic field models which include the effects of amplitude fluctuations [3].