Influence of the anthocyanin concentration in ethanolic extracts of Hibiscus Sabdariffa on thermocavitation: An analysis of the pulse frequency and amplitude

•The transmitted light observed as a pulse, could relate with bubble evolution.•Frequency increase with the intensity of the beam or anthocyanins concentration.•Increasing anthocyanin concentration results in a less variation of amplitude.•Thermocavitation can controlled by exploiting the optical properties of materials. An analysis of thermocavitation in a nonlinear optical material (natural dye, ethanolic extract of Hibiscus Sabdariffa) is presented. Thermocavitation consists of generating bubbles using a highly focused CW laser beam in a highly absorbent liquid solution. The thermocavitation frequency can be modified by varying the incident beam power or the absorption of the solution. In this work, we report an analysis of the thermocavitation pulse frequency and amplitude in a Hibiscus Sabdariffa solution when the laser intensity and the concentration (absorption) of the material are varied. Our results show a direct dependence of the frequency rate on the concentration and an inverse relation with the pulse amplitude.