Lasers in medicine are very specific in what they accomplish and selecting the right laser for tattoo removal is important.
Nd: YAG Lasers
The best lasers for the past 30 years or more for laser tattoo removal have been Q-switched Nd:YAG lasers. Nd:YAG (neodymium ytrium aluminum garnet) stands for the crystal in the laser which produces the wavelength of light which is 1064 nanometers. This wavelength is absorbed well by most black inks and is effective at penetrating relatively deep in the skin compared to lasers with shorter wavelengths. These lasers generally also have a frequency doubling crystal that cuts the wavelength in half (532 nm) making it also very effective at removing more red and some orange inks.
Hoya ConBio (Now Cynosure)
The Medlite II, made by Hoya ConBio, was the most popular Nd:YAG laser for many years but was gradually replaced by newer generation Medlite C6 and Revlite lasers. These lasers also have polymer hand pieces, which convert the 532 nm wavelength into 585 nm and 650 nm to help with blue and green inks respectively. Unfortunately, these can only fire once or twice per second (compared to ten pulses per second) and cannot be adjusted with respect to spot size or energy, which significantly limits their effectiveness.
2013 has seen a revolution in laser tattoo removal with the introduction of the PicoSure laser by Cynosure, which also now makes the Medlite C6 and Revlite lasers. It is a Q-switched alexandrite laser giving it a wavelength of 755 nm which is much more effective on green and blue inks. The innovation, however, is the speed of the pulse of light delivered by the laser. Rather than firing in nanoseconds (Billionths of a second), it fires in picoseconds (Trillionths of the second). This faster delivery of light breaks up the ink particles into finer particles than the Nd:YAG lasers which makes it easier for your immune system to get rid of the treated tattoo ink particles.
There is a vast array of lasers available for treating a variety of medical conditions. Most of them are specific in their indications and almost all of them are very expensive. Unfortunately, when a practice spends a substantial amount of money for a machine, there is a financial incentive to use it as much as possible in an effort to justify the purchase. As the saying goes, 'when the only tool you have is a hammer, the world begins to look like a nail.' I have seen numerous patients permanently scarred by the use of inappropriate lasers for tattoo removal. Probably the most egregious is a CO2 laser, which has absolutely no potential benefit in tattoo removal and, when used below the neck, has a high likelihood for irreversible scarring.
Check With the FDA
Before getting a treatment with a laser, find out the model and manufacturer and see if that laser is FDA approved for the treatment you are considering. In addition, make sure that the person performing the procedure is trained and allowed to use the machine. In the state of Ohio, only a physician can perform laser tattoo removal. In fact, the only laser procedure that can be performed in Ohio by a non-physician is laser hair removal.