The laser’s beam is fundamentally a super-energized beam of light energy. The light waves, called photons, are made to all travel parallel to one another (coherent) thus focusing and augmenting the power of the combined lightwave.

These are at different wavelengths based on the material used in producing the laser. Sometimes that light is visible and other times it is in the invisible spectrum. The different types or wavelengths have different properties and are absorbed differently by different tissues.

For example, some wavelengths are better absorbed by the red color of blood than by the dark pigment (melanin) of hair. We take advantage of these differences in selecting lasers for various purposes. These intense, highly focused beams carry a lot of energy with them. When a particular tissue absorbs the laser energy, it produces a burst of heat energy. At the surface of the skin, for example, when the energy is absorbed it causes the water in skin cells to vaporize and the skin cells with it. This, in principle, is the way the resurfacing laser works. In the case of a hair removal laser, the energy is absorbed in the most vulnerable part of the hair follicle.