YAG Laser

The Ytterbium Aluminum Garnet, or YAG laser is an eighty-thousand dollar tool responsible for turning the process of tattoo removal into a simple medical procedure costing a few hundred bucks.

Before the advent of laser tattoo removal in the early Nineties, the only options available to those wishing to get rid of their rather stubborn tattoos were skin grafts costing thousands of dollars or disfiguring home remedies such as battery acid or flame-heated spoons.

Where earlier laser treatments simply burned the tattoo away, the YAG laser is calibrated to break up or vaporize ink particles one color at a time into smaller units that the patient's own immune system can dispose of.

The yttrium aluminium garnet(YAG) laser is a solid state laser that use a YAG crystal as the lasing media. The YAG crystal is often treated with neodymium to get the desired output wavelength. The YAG crystal is placed in a standard laser resonator cavity( between two mirrors, one of which is semitransparent). When the crystal is exposed to a high energy light pulse(like from a xenon tube) or constant high power light source, the crystals atoms will emit photons. some of the photons will escape through the sides of the crystal rod, but some will bounce between the mirrors, and stimulate the atoms to send out more photons (

This laser type usually emits infra red light at a wavelength of 1064 nanometer. It is often used in industry as a cutting or drilling tool and in medicine in surgical applications. This laser type is typically more dangerous than for example the HeNe laser and the diode laser since it's light is invisible and output effects of near 1 kilo watts is not uncommon. This mean that direct contact with the beam will burn or cut and even a reflex of the beam can instantly damage the retina in an eye. Therefore 1064nm filter glasses must be used if there are any danger of exposure to reflections.