The short answer
Both lasers break up pigment. The difference is the pulse. A picosecond pulse lasts about a trillionth of a second. A Q switched, or nanosecond, pulse lasts about a billionth of a second, roughly a thousand times longer.
Pulse width decides how much energy turns to heat in the skin around the pigment. Here, the T2 Frax Radiance protocol on the DEKA TORO has picosecond and nanosecond emissions, so pulse width and wavelength are chosen per mark and per visit.
Pico vs Q switched laser at a glance
| Pico (picosecond) | Q switched (nanosecond) | |
|---|---|---|
| Pulse | About a trillionth of a second | About a billionth of a second |
| Main effect | Pressure, with little heat spreading | More heat, which spreads into nearby tissue |
| Common wavelengths | 532 nm and 1064 nm, and 785 nm picosecond on the DEKA TORO | 532 nm and 1064 nm |
| Often used for | Discrete sun spots and freckles, fractional texture work, tattoo ink | Low-fluence 1064 nm toning for diffuse tone and brown acne marks |
| Melasma | Conservative add-on only | Conservative low-fluence toning only |
| Caution | Fluence, spot size, passes, interval and sun still matter | Needs conservative settings and pacing |
What this means for Singapore skin
In Fitzpatrick III to V skin, post-inflammatory hyperpigmentation is the main concern. Pico is often the first choice for discrete spots in darker skin, as its heat component is lower. Low-fluence 1064 nm toning is also workable in Singapore skin. But a careless picosecond treatment can darken pigment just as a nanosecond one can. Fluence, spot size, number of passes, interval and sun exposure all change the outcome, whichever pulse is used. The device name matters less than how it is set and paced.
Melasma is a separate question
Melasma is managed rather than removed. Hormonal, vascular and ultraviolet factors drive it, and no laser addresses those. Heat can trigger it. So any laser is an add-on to diagnosis, sun protection and topical therapy. Aggressive settings are declined, whichever pulse is used. See melasma treatment.
Who should wait
A recent tan or sunburn, active infection or inflammation in the area, photosensitising medicines, a keloid tendency, or pregnancy.
Any changing, bleeding or irregular mark must be examined and referred for dermatological assessment first.
Sun spots, freckles, brown acne marks and melasma are planned differently, so the type of pigment is established before a laser is chosen.
What neither laser can do
Lasers break up existing pigment. They do not address why the skin produced it.
It can only be managed, and any laser is an add-on.
Toning does not run on an open-ended schedule. The plan has a stopping point.
Risks of either laser
Both carry a risk of post-inflammatory hyperpigmentation.
These can follow repeated toning.
This can occur with either pulse type.
Too much energy can cause blistering or texture change.
Sessions, recovery and fees
No fixed session count or recovery period is given. Response is assessed between visits, which are paced with strict sun protection. Fees depend on the type and extent of pigment and on staging, and they are set out in writing after consultation. No prices are listed. Dr Sin Yong performs treatment personally after assessment.