Wavelength Dependence of Water Microdroplet Shattering with Dual IR Lasers and Dye Sensitization

Abstract

Abstract We have used time-resolved imaging to examine the effect of incident radiation wavelength in the range 2.75–3.75 μm on the shattering of water microdroplets by single and dual lasers. Dye sensitization of microdroplets was induced by using the water-soluble dye sulforhodamine G; this enabled us to observe both the forward and backward components of fragmented droplets and splashes. Compared with employing a single IR laser, simultaneous illumination by two IR lasers can effectively compress the spatial distribution of small fragments around the absorption maximum for the OH-stretching vibration of liquid water (λ = 2.75–3.25 μm). Scattering and compression of the fragmented microdroplets after single and dual IR laser irradiation can be explained by conservation of momentum.