Femtosecond laser energy deposition in strongly absorbing cluster gases diagnosed by blast wave trajectory analysis

An intense ultrafast laser pulse can be very strongly absorbed in a moderat e density gas composed of van der Waals bonded clusters. In this paper, the deposition of the energy of intense 30 fs light pulses in a gas of deuteri um clusters has been diagnosed using a technique based on analysis of the t rajectories of the resulting cylindrically symmetric blast waves. Using the well-known relation between blast wave velocity and energy deposition in g as, the laser energy deposited per unit length as a function of distance in gas jet plume was measured. These measurements were conducted in jets cont aining either deuterium clusters or simple deuterium molecules. (C) 2001 Am erican Institute of Physics.