Experimental modelling of the physical process of laser tattoo removal

Two model objects are proposed to study the physical mechanism of tattoo removal using nano-, pico-, and femtosecond laser pulses. Experimental results on laser decolourisation of cotton fabric coloured with black tattoo ink and a pig skin sample with tattoo ink deposited on its rear side, in dependence of the duration, energy, and number of laser pulses and the laser spot size, are presented and discussed. It is established that decolourisation of cotton fabric and pig skin without their destruction occurs under irradiation with ultrashort laser pulses and is absent in the case of nanosecond pulses. An analysis of the results obtained has made it possible to draw a number of conclusions, useful for gaining a better insight into the physical mechanism of laser tattoo removal.