Nd:YAG laser wavelengths: 532 and 1064 nanometres
Nd:YAG laser tattoo removal uses 1064 and 532 nm: which pigment colours each wavelength removes, how deep each reaches and why 1064 nm is invisible.
The main wavelength of Nd:YAG lasers is 1064 nm. Using a special tip (potassium titanyl phosphate, KTP) we can "double the frequency" and get a wavelength of 532 nm.
Which colours does each wavelength remove?
If a client comes to you with old PMU (permanent makeup) — black and its shades — you should use the 1064 nm wavelength.
But a red rose tattoo can only be removed with the 532 nanometre wavelength, because red absorbs wavelengths in this range well!
In addition, different wavelengths penetrate the skin to a particular depth!
If you treat a tattoo with a 532 nm laser beam, its maximum penetration depth is the upper layers of the dermis. The 1064 nm wavelength, however, can reach the hypodermis!
This is shown visually in the photo below:
However, do not think that the 532 nm beam is worse at removing tattoos! The wavelength is chosen so that the substance (the pigment) absorbs as much of the laser radiation as possible.
They say you cannot see the 1064 nm wavelength. Is that true?
It is true. You can see the 532 nm beam (green), because it falls within the visible spectrum. But the eye cannot detect the 1064 nm wavelength! This is where you need an aiming beam that shows the direction of the laser and the spot where the pulse will land.
Which colour will an Nd:YAG laser remove?
Pick a pigment colour — an Nd:YAG laser has only two wavelengths: 1064 and 532 nm.
A simplified scheme based on the article on which colours an Nd:YAG laser can remove.
Frequently asked questions
Which Nd:YAG wavelength removes black tattoo ink?
1064 nm. If a client comes with old PMU in black and its shades, you should use the 1064 nm wavelength.
Which wavelength removes red tattoo ink?
532 nm, because red absorbs wavelengths in this range well. It is obtained from the main 1064 nm wavelength with a KTP tip that doubles the frequency.
How deep do 532 nm and 1064 nm reach into the skin?
The maximum depth of 532 nm is the upper layers of the dermis, while 1064 nm can reach the hypodermis. That does not make 532 nm worse: the wavelength is chosen so that the pigment absorbs as much radiation as possible.
Can you see the 1064 nm laser beam?
No. The 532 nm beam is visible as green, but the eye cannot detect 1064 nm, so you need an aiming beam that shows where the pulse will land.
