Diode laser hair removal

Treatment principle and Advantage

Laser hair removal focuses on the endogenous chromophore melanin, which is mainly found in the hair shaft, with a small amount present in the upper third of the follicular epithelium (Figure

When an appropriate energy source (such as a laser) is directed at the skin, light is primarily absorbed in the hair shaft melanin. Heat is generated and diffuses to the surrounding follicular epithelium. A similar principle applies to laser treatment of vascular lesions, where the heat generated after absorption by hemoglobin is transferred from the blood to the vascular endothelial cells.

Wavelengths between approximately 700 and 1000 nanometers (nm) are selectively absorbed by melanin; the competing chromophores (oxyhemoglobin and water) absorb less energy at these wavelengths. Figure 2 shows the absorption of different chromophores in the skin. Therefore, any light source that operates between 700 and 1000 nm is appropriate for targeting melanin in the hair shaft.