An experiment is described in which an apparatus is used to demonstrate the feasibility of measuring multiphoton photoionization rates in the interaction of short pulsed lasers with atoms or molecules. With this methodology, the ionization rate is measured as a function of the spatial position in the beam-waist region of the laser through the direct three-dimensional spatial imaging of the ionization events. Thus, if the spatial dependence of the laser beam intensity were known, a series of experiments could yield the intensity dependence of multiphoton ionization without the assumptions or errors that are generally inherent in the integration over one or more dimensions in the laser focal volume.
© 2004 Optical Society of America
Richard Bredy, Howard A. Camp, Hai Nguyen, Takaaki Awata, Bing Shan, Zhenghu Chang, and B. D. DePaola, "Three-dimensional spatial imaging in multiphoton ionization rate measurements," J. Opt. Soc. Am. B 21, 2221-2226 (2004)