The word “laser” is in fact an acronym, standing for Light Amplification by the Stimulated Emission of Radiation…and thus a new word is born! LASER. The amazing thing about lasers is that they harness the power of light, and then control it.
What makes laser light different from normal light is that it has a single wavelength (as opposed to the whole spectrum of wavelengths of visible light). Lasers work by producing an intense beam of bright light of a single frequency, which travels in one direction. Ordinary light, as we know it, is composed of many different colors, and appears white. A laser on the other hand has the unique ability to produce one specific color or wavelength.
The laser light targets the chromophores in the skin. Chromophores are naturally occurring pigment that selectively absorbs light at certain wavelengths. As each wavelength is absorbed differently by the skin, lasers are successfully used to target specific structures within the skin, such as hair, without causing damage to surrounding tissue. This process is known as "selective photothermolysis".
The laser emits a gentle beam of light that passes through the skin where it is absorbed by the melanin (color) in your hair. As it is absorbed, the laser energy is transformed into heat which then disables the hair follicle and prevents further growth.
But enough of the techno-speak! Although the lasers used today do emit radiation, the levels are low, and the frequency well inside the non-ionizing range (as opposed to the ionizing range where X-rays, etc are categorized). Laser used for medical and aesthetic procedures, such as laser hair removal, are typically classified as Class IV lasers and require approval by the FDA.