The word laser is an acronym in English for light amplification by stimulated emission of radiation.
A laser is a device consisting of a solid, liquid or gas medium inside a cavity limited by two parallel mirrors, one of which is semitransparent. If the atoms of that medium are stimulated, they reach an unstable level of energy and in order for them to return to their initial state they release that energy in the form of photons. Part of that light bounces to the outside through a semitransparent mirror in the form of pulses or a continuous beam.
Thus, a laser produces a beam of bright, monochromatic, collimated controllable light that enables the delivery of a large quantity of energy into one of the pigments in the skin.
Laser technology began back in 1900 when Einstein formulated the concept of stimulated light emission. Mairman, who developed the first 694nm, monochromatic light laser, first applied this theory to the skin in 1959.
In 1963, a dermatologist named Leon Goldman began to treat different skin conditions using the ruby laser.
In the 1980s, Anderson and Parrish developed the principle of selective photothermolysis, which greatly improved and boosted the use of laser technology.
In 1988, Dierickx published the effects of ruby laser in permanent hair removal for the first time. In 1995, Goldberg used the Nd:YAG laser for hair removal. From this moment on comparative studies were carried out to demonstrate the efficacy of laser hair removal, being Nestor’s work in 1998 one of the most significant, with more than 2000 treated cases. Other authors who have proven its efficacy are: Goldberg et al. in 1997, Bjerring et al. in 1998, Grossman in 1999, Campos et al. in 1999, etc.
Laser hair removal is elimination of unwanted hair using light energy.