SP is a method for localizing tissue damage to specific chromophore targets at the cellular level therefore, it can be used to minimize undesired thermal damage to the surrounding tissue caused by thermal diffusion.
The principle on which all cosmetological lasers work and gives expected results. The word photothermolysis comes from three Greek root words -- "photo" meaning light, "thermo" meaning heat, and "lysis" meaning destruction. Selective photothermolysis therefore refers to the precise targeting of a structure or tissue using a specific wavelength of light with the intention of absorbing light into that target area alone. The energy directed into the target area produces sufficient heat to damage the target while allowing the surrounding area to remain relatively untouched.