Time evolution of the caustics of a laser heated liquid film.
The free surface of a liquid film of black oil is deformed by heating with a Gaussian laser beam, thus changing the intensity distribution in the reflected and transmitted beams. The time evolution of the caustics of those beams is numerically studied. The topological structure of the caustics abruptly changes at three critical instants of time. Measurement of the divergence of the caustics of the reflected and transmitted beams allows one to deduce the liquid refractive index.
Da Costa
G
G
Escalona
R
R