The primary principle behind all laser hair removal is selective photothermolysis, the matching of a specific wavelength of light and pulse duration to obtain optimal effect on a targeted tissue (hair) with minimal effect on surrounding tissue (skin). Several wavelengths of laser energy have been used for hair removal. These lasers are characterized by their wavelength, measured in nanometres (nm). Some lasers are more effective for treating hair, or for treating particular skin colours, and some lasers penetrate deeper than others.
Diode’s 810nm is widely accepted as the “Gold Standard” wavelength in laser hair removal, due to its optimal melanin absorption and its increased penetration deep into the dermis where the hair follicle is located. Compared to other lasers where the laser light may be concentrated at the surface of the skin (many charred hairs may be noted with these treatments), diode treats deeper and is more effective where we want the light/heat to create damage - the hair bulb.