Nd:YAG laser:
what the term means

Where the Nd:YAG laser matters on this site

At 1064 nm the Nd:YAG wavelength is absorbed by melanin, haemoglobin and, weakly, water, but less strongly than shorter wavelengths, so it penetrates deeper and spares the epidermis. That profile makes it the default long wavelength for Singapore skin, and it appears across the site in three pulse forms.

Nd:YAG is a crystal; before I use it I decide the pulse, because a long pulse and a nanosecond pulse are two different instruments.— Dr Sin Yong

• Nd:YAG laser: the treatment page, with the long-pulsed, Q-switched and picosecond forms set out by job.
• R2 Glow: Dr Sin Yong's long-pulsed 1064 nm and 755 nm protocol aimed at the inflammation that keeps producing pigment and redness.
• Laser toning: low-fluence 1064 nm passes for diffuse tone, with the site's caution about frequent repetition.
• Laser hair removal: where long-pulsed 1064 nm is matched to deeper skin tones.
• Facial thread veins: the deeper, blue-purple vessels that long-pulsed 1064 nm reaches.

For hair removal on darker skin the dark skin page explains why 1064 nm is chosen over 755 nm; the diode vs alexandrite vs Nd:YAG comparison does the same across all three.

Not to be confused with

"Nd:YAG" names a crystal and a wavelength, not a treatment. The confusions below come from treating it as a brand.

• Q-switched laser. A pulse form, nanosecond, that an Nd:YAG can be built in. Q-switched 1064 nm fragments pigment; long-pulsed 1064 nm heats hair, vessels and inflamed dermis. Same crystal, different job.
• Picosecond laser. Many pico platforms are also Nd:YAG at 1064 and 532 nm; the pulse is roughly a thousand times shorter than Q-switched. The pico laser page covers that form.
• Alexandrite laser. 755 nm, more strongly absorbed by melanin, favoured on lighter skin. The two are paired in R2 Glow.
• Laser toning. A protocol using low-fluence 1064 nm, not a different machine. Repeated toning has been linked to pale, mottled spots, as the laser white spots post describes.
• KTP 532 nm. The frequency-doubled output of the same crystal, absorbed strongly by haemoglobin and melanin and used superficially.

Asking "which Nd:YAG" means asking which pulse width and which fluence.

What decides whether an Nd:YAG laser matters for you

The wavelength suits Singapore skin, but the pulse form and the indication decide whether it is the right tool for you.

• What is being treated. Hair and deeper vessels call for a long pulse; dermal pigment and tattoo ink call for Q-switched or picosecond pulses; diffuse inflammation in rosacea-prone or melasma-prone skin is approached with long-pulsed low-energy passes.
• Skin type. 1064 nm is only modestly absorbed by epidermal melanin, which is why it is workable across Fitzpatrick III to V; the grade still sets fluence and cooling.
• Melasma. Managed rather than removed on any Nd:YAG form, with sun protection and medical treatment first; see pico laser for melasma for the staged approach.
• Treatment history. Many previous toning passes change what can safely be added, because of the risk of mottled hypopigmentation.
• Hair colour. The chromophore is melanin in the hair shaft, so grey or very fine hair responds poorly at any wavelength.

Dr Sin Yong chooses the pulse form per mark and per visit, which is why the same machine appears on pages about hair, redness and pigment.