Nd:YAG Laser Singapore —
One Wavelength, Several Pulse Lengths

Nd:YAG stands for neodymium-doped yttrium aluminium garnet, the crystal that produces the light. Its main wavelength is 1064 nm, in the near infrared. Many platforms can also produce 532 nm, a green wavelength for red and superficial targets.

The useful property of 1064 nm is that melanin in the upper skin absorbs it only modestly. More of the energy passes the surface and reaches the dermis, where deeper pigment, hair roots and larger vessels sit. Shorter wavelengths such as 532, 694 and 755 nm are taken up more strongly by melanin, which makes them efficient on a pale background and less forgiving on medium and darker skin.

That margin is not permission to turn the energy up. A 1064 nm laser can still burn, darken or lighten skin when the settings do not fit; the wavelength widens the gap between enough and too much, nothing more.

A short, intense pulse breaks pigment apart; a longer one heats a structure slowly. That is why "YAG laser" in an advertisement can describe quite different treatments, and why the pulse form, not the crystal, is the first question to ask.

• Q-switched: nanosecond pulses with a very high peak, which fragment pigment granules and dark tattoo ink.
• Low-fluence Q-switched (laser toning): the same nanosecond pulses at energy below the level that destroys pigment cells, passed repeatedly to even out diffuse tone.
• Long-pulsed: millisecond pulses with surface cooling, which heat hair follicles, deeper or blue-purple vessels and collagen gradually.
• Picosecond: even shorter pulses that act mainly by pressure rather than heat. Many pico lasers are Nd:YAG lasers with a shorter pulse.

A 1064 nm laser tends to suit:

• Hair removal in Fitzpatrick IV to VI skin, or tanned skin, where long-pulsed 1064 nm is the usual choice and the 755 nm alexandrite suits lighter skin. See laser hair removal for darker skin.
• Deeper or blue-purple facial vessels, once the cause of the redness has been assessed.
• Brown marks left by acne and a generally uneven tone, weighed against what caused them.
• Black and dark-blue tattoo ink, which absorbs 1064 nm well.

It is the wrong tool for white, grey or very fine hair, which has too little pigment to absorb the light. It does not remove melasma: melasma is managed, and open-ended toning is declined. Laxity, acne scars and enlarged pores are better matched to other treatments, such as RF microneedling.

1. At consultation Dr SY examines the skin in good light, with a dermatoscope where needed, records your skin type and asks about recent sun, medicines and past treatments. Photographs are taken with your consent for your medical record only.
2. Where your reaction is uncertain, a small test patch comes first and is checked after the delay in which darkening would show.
3. On the day, the skin is cleansed and everyone in the room wears eye protection suited to 1064 nm, which the eye cannot see.
4. Settings are chosen for the area and target, with cooling where needed.
5. Afterwards the skin is cooled if warm, sunscreen goes on, and you leave with written aftercare for that treatment.
6. Each next step is decided at a follow-up visit, from how the skin responded.

Aftercare depends on the treatment and is given on the day. In general: cool the area if it feels warm; avoid saunas, hot showers and strenuous exercise for a short period; use broad-spectrum sunscreen and shade, which in Singapore means every day of the year; leave any crusts or shedding hairs alone; and keep retinoids, acids and scrubs off until the skin has settled. Hair-removal care is on laser hair removal aftercare, and toning for melasma on melasma treatment aftercare.

Expected: redness, warmth and mild swelling around treated follicles or vessels, settling over hours to a day or so.

Less common: blistering, crusting, temporary darkening (post-inflammatory hyperpigmentation) and lightening. Repeated aggressive toning can leave pale, mottled spots, which is why a course is paused at the first sign of them; see white spots after laser. After hair removal, increased hair growth at the edges of a treated area has been reported. Settings matched to skin type, cooling and test patches lower these risks.

Contact the clinic promptly if blisters form, redness spreads, or the colour of the treated skin changes.