Expansion and Fragmentation of a Liquid-Metal Droplet by a Short Laser Pulse

Fragmentation of liquid-metal droplets by short laser pulses is a key phenomenon in producing a bright extreme-ultraviolet (EUV) light source for next-generation nanolithography. The complex multiphysics processes leading to the fragmentation are still not well understood, though. This study surprisingly reveals the emergence of either symmetric or asymmetric scenarios for droplet expansion, depending on laser intensity. This insight can be used to optimized laser-pulse characteristics to guide droplet break-up.