Laser tattoo removal may sound like science fiction, but it has been performed for years. The different types of lasers used are all very similar in construction and function, but different crystals are used in each type. The most common types of lasers used for tattoo removal are:

• Q-Switched Ruby Laser:
  This was the first laser used for tattoo removal. The light wavelength of 694nm makes this useful for green tattoos (the most difficult to remove). Although special care must be taken when treating someone with dark skin, this laser is still very useful for removal.
• Q-Switched Nd:
  YAG Laser. Introduced in 1991, the neodymium: yttrium-aluminum-garnet laser became the most heavily-used laser in the tattoo removal industry. This laser can operate alone at a wavelength of 1064nm (effective for removal of dark blue or black ink) or with a frequency-doubling crystal to shorten the wavelength to 532nm (effective for removal of red or orange ink).
• Q-switched Alexandrite Laser:
  This laser, introduced in 1992, operates at a wavelength of 755nm, which resides between those of the ruby and neodymium: YAG lasers. It is excellent for the removal of green and blue-black tattoos.

All of these lasers are highly useful for tattoo removal, but as you can see, certain lasers more effectively remove certain colors. You should consider finding a clinic that uses all three lasers (as many do), because this will greatly increase your chances of effectively having your tattoos removed.