Simulation of an optically induced asymmetric deformation of a liquid-liquid interface

Abstract

Deformations of liquid interfaces by the optical radiation pressure of a focused laser wave were generally expected to display similar behavior, whatever the direction of propagation of the incident beam. Recent experiments showed that the invariance of interface deformations with respect to the direction of propagation of the incident wave is broken at high laser intensities. In the case of a beam propagating from the liquid of smaller refractive index to that of larger one, the interface remains stable, forming a nipple-like shape, while for the opposite direction of propagation, an instability occurs, leading to a long needle-like deformation emitting micro-droplets. While an analytical model successfully predicts the equilibrium shape of weakly deformed interface, very few work has been accomplished in the regime of large interface deformations. In this work, we use the Boundary Integral Element Method (BIEM) to compute the evolution of the shape of a fluid-fluid interface under the effect of a continuous laser wave, and we compare our numerical simulations to experimental data in the regime of large deformations for both upward and downward beam propagation. We confirm the invariance breakdown observed experimentally and find good agreement between predicted and experimental interface hump heights below the instability threshold.

References in corpus (4)

• Laser-induced hydrodynamic instability of fluid interfaces
• Liquid Transport Due to Light Scattering
• Asymmetric Optical Radiation Pressure Effects on Liquid Interfaces Under Intense Illumination
• Non-Linear Deformations of Liquid-Liquid Interfaces Induced by Electromagnetic Radiation Pressure

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• Optohydrodynamics of soft fluid interfaces : Optical and viscous nonlinear effects
• Excitation of fountain and entrainment instabilities at the interface between two viscous fluids using a beam of laser light
• Numerical simulation of universal morphogenesis of fluid interface deformations driven by radiation pressure