Enhanced explosion of atomic clusters irradiated by a sequence of two high-intensity laser pulses - art. no. 044101

Experiment and numerical simulations have shown that the heating of atomic clusters can be enhanced by using a correctly timed sequence of two high-in tensity pulses of different frequencies. We have measured ion energies from Xe clusters irradiated with two high-intensity femtosecond laser pulses, o ne at the laser fundamental frequency (780 nm) and one at its second harmon ic (390 nm), focused to an intensity of similar to 10(15) W cm(-2). The ion energies are found to depend on the relative delay of the two pulses but n ot on their relative polarizations. For the optimum value of the delay betw een the two laser pulses, the maximum ion energy is doubled from 100 to 200 keV. The laser energy required to obtain a given ion energy is significant ly less when the cluster is irradiated with two pulses of different frequen cies than a single laser pulse.