Lasing images from two merging ink-doped liquid droplets

Lasing images from two merging ink-doped ethanol droplets (size ~37 microm), which were generated by modulation techniques and pumped by nanosecond laser pulses, were photographed through a microscope. By measuring the size difference of two adjacent droplets from the spectral shifts of lasing peaks, we confirmed that mass transfer occurred in the breakup process of the liquid jet. We observed lasing images from merging droplets in a variety of patterns. Noteworthy among these is the lasing from snowman-shaped droplets that are conjectured to stem from coupled modes with orbits around both droplets.