Pulse activation of superheated liquid boiling-up by laser radiation

The possibility of local activation of liquid boiling-up by a laser pulse at the end of a single-mode light guide is shown on the example of $n$-pentane superheated at 81$^\circ$C relative to the liquid–vapor equilibrium temperature. An activation threshold is detected for the radiation intensity at the end of the light guide. Its value depends on the state of the light guide end, and the boiling processes are likely to develop at the interface. As with the random boiling-up process, upon activation, a stepwise propagating change in the refractive index of the liquid is observed. A conclusion is drawn on the uniformity of the recorded processes during random and activated boiling-up of $n$-pentane.