What happens to the ink during the laser tattoo removal process?

In order to have a good understanding of how laser tattoo removal works it's important to understand how the tattoo is made to make it permanent.

Tattoos are made using a motorized needle, this needle pricks holes in the upper epidermal layers, and at the same time this needle injects the ink into those holes, that ink then connects together with the skin molecules which make the tattoo permanent.

The ink in your tattoo gets broken down by the laser delivering a high-energy beam of light at a specific frequency. The energy and frequency of the laser can be changed so that the right amount of energy is delivered depending on the tattoo and what stage of treatment you are at.

The high energy light breaks up the ink particles into tiny fragments which are taken up by the macrophages scavenger cells in the skin and carried away by the body's waste removal system. As the pigment is carried away the tattoo gradually disappears. Simple tattoos may dissolve after three or four treatments, but usually, six to eight treatments are required. This can be more for very large and complex tattoos.

Source: Laser Tattoo Removal