Nanobubbles in Nanodroplets (IMAGE) University of Freiburg Caption Excitation of helium nanodroplets by ultra-short laser pulses. Credit Photo: AG Stienkemeier Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.