Sounds cool, right? But the process can often take several treatments, as recovery is determined on more than just time as a factor, but diet and your immune system too. Darker pigments are usually eliminated much easier than those which are light of colour and shade.
It can also be slightly painful, so much more than getting the tattoo in the first place, although more than likely done much quicker. The laser heats the ink particles to thousands of degrees, but the flash happens so quick that the laser does not burn the tissue. The energy vibrates through the skin, causing the upper layer of the skin to lift up and 'frost'. This only lasts a few seconds, the frosting can last up to half an hour in some cases.