ADIABATIC STABILIZATION AGAINST PHOTOIONIZATION - AN EXPERIMENTAL-STUDY

We describe a detailed account of an experiment demonstrating light-in duced stabilization against photoionization. The choice of initial sta te and atom is discussed in relation to the laser wavelength and laser pulse duration. In combination with a 100-fs, 620-nm probe pulse, the optimum choice is the circular 5g state in neon. A picosecond pump la ser was used to prepare this Rydberg state. Initially, the population in this state was probed with a nanosecond laser pulse. Subsequently, the nanosecond probe pulse was replaced by an intense, (sub)picosecond pulse and the photoionization signal was studied. When the probe inte nsity is several times 10(13) W/cm(2) a decrease in yield with respect to a less intense pulse with the same fluence is observed, which indi cates stabilization. The results are in accordance with recent theoret ical predictions.