The short version
Pico (picosecond) laser delivers ultra-short pulses measured in trillionths of a second. The pulses are so brief that they shatter pigment particles through a photo-acoustic effect rather than relying primarily on heat. This means less thermal damage to surrounding tissue, which translates to lower risk of post-inflammatory hyperpigmentation in darker skin tones.
Nd:YAG (1064nm Q-switched) is the older nanosecond-pulse technology. Pulses are about 1,000 times longer than picosecond, so the mechanism is a mix of photo-acoustic and photo-thermal effect. Still effective for many pigmentation types but generally produces more thermal injury at equivalent treatment energy.
Why pulse duration matters
The fundamental concept is "thermal relaxation time" — how long it takes a target (like a melanin particle) to dissipate the energy it absorbs as heat. If your laser pulse is shorter than the thermal relaxation time, you deliver mechanical disruption with minimal heat spread. If it's longer, surrounding tissue absorbs heat too.
Melanin particles have a thermal relaxation time on the order of nanoseconds. So nanosecond Q-switched lasers (like Nd:YAG) are just at the edge of selectively targeting melanin. Picosecond lasers (1000× shorter) are well below this threshold — the energy goes into shattering the pigment with minimal thermal collateral.
The Singapore skin-tone factor
Most Singaporean patients are Fitzpatrick skin types III to V — meaning more responsive melanocytes that produce more pigment in response to any inflammatory stimulus, including aesthetic laser heat.
This is why pulse duration matters even more here than in temperate climates. Excessive thermal injury risks post-inflammatory hyperpigmentation (PIH) — the very thing you're trying to treat. Picosecond's lower thermal footprint makes it more forgiving for Singapore skin.
Side-by-side comparison
How our doctors choose
For surface sunspots and lentigines
Pico is usually first choice. Single-session response is often dramatic for individual sunspots. Recovery is faster and PIH risk is lower in Fitzpatrick IV-V skin.
For melasma
Pico at conservative settings, ideally combined with topical therapy. Aggressive Nd:YAG settings can flare melasma; we avoid this.
For tattoo removal
Pico is generally superior — particularly for difficult colours (green, blue, multi-coloured tattoos) and faded tattoos with finer pigment particles.
For overall skin brightening / rejuvenation
Pico has a "Pico Toning" protocol delivering low-fluence pulses across the full face. The accumulated mild thermal effect stimulates collagen and refines skin tone. Nd:YAG has equivalent low-fluence protocols ("laser toning") but with marginally more thermal load.
For acne scars
Pico can help with mild atrophic scars and post-acne hyperpigmentation. For deeper scarring, fractional RF microneedling is typically more effective.
Is pico always the answer?
Not always. Nd:YAG remains relevant because:
- It's an older, well-characterised technology with extensive clinical data
- For certain pigmentation patterns (some types of solar lentigines), the marginal benefit of pico over Nd:YAG is small
- Cost-per-session is typically lower with Nd:YAG, which matters for some patient budgets
- Some clinics have Nd:YAG platforms with longer track records and senior doctor familiarity
The clinical decision is more nuanced than "newer is better."
What to do next
If you're considering laser treatment for pigmentation, the right starting point is a proper Wood's lamp or dermatoscope assessment to classify your pigmentation pattern. The right laser depends entirely on what you're treating.