Selective photothermolysis

Sel­ec­ti­ve pho­to­ther­mo­ly­sis is the basic prin­ci­ple behind every laser tre­at­ment of the skin. It sta­tes that if a wave­length is cho­sen that is pre­do­mi­nant­ly absor­bed by a par­ti­cu­lar tar­get struc­tu­re, and the pul­se is short enough, only that struc­tu­re heats up.

Appli­ca­ti­on

The tar­get struc­tu­re is cal­led a chro­mo­pho­re. Mela­nin is the tar­get in hair rem­oval and pig­ment spots, red blood pig­ment in vas­cu­lar chan­ges, water in abla­ti­ve pro­ce­du­res and tat­too ink when remo­ving tattoos.

Good to know

This prin­ci­ple explains why no sin­gle laser can do ever­y­thing, and why tan­ned skin is a pro­blem: the addi­tio­nal mela­nin in the epi­der­mis absorbs ener­gy that is meant to reach the tar­get at depth.

Matching tre­at­ment at Swiss Der­ma Cli­nic: Laser tre­at­ment