Selective Photothermolysis for Laser
Selective photothermolysis is the science that makes modern laser hair removal both effective and skin-conscious. If you’ve searched “laser hair removal near me” and want to understand why treatment is done as a series, this page explains how light energy targets pigment in the hair follicle while cooling helps protect the surrounding skin to achieve selective laser hair removal.
Photothermolysis Settings: Wavelength, Pulse & Cooling
“Selective photothermolysis” sounds technical, but the idea is simple: choose light that the target absorbs, deliver it fast enough to confine heat, then protect the skin surface while the follicle heats. This principle was formally described in classic dermatology laser literature; if you’d like to read the original concept, see the selective photothermolysis paper on PubMed.
Wavelength determines what absorbs the energy (the “chromophore”). For hair removal, the key chromophore is melanin in the hair shaft and follicle. Different wavelengths penetrate to different depths, which is one reason settings are not one-size-fits-all.
Pulse duration is how long each pulse lasts. Matching pulse duration to the follicle’s ability to cool (its “thermal relaxation time”) helps keep heat in the follicle long enough to disrupt regrowth, without unnecessarily heating surrounding skin.
Cooling (and the overall treatment technique) is the safety partner to energy delivery. By cooling the epidermis and using appropriate parameters, the treatment aims to heat the follicle more than the skin surface, which improves comfort and reduces the risk of adverse skin reactions.
