Picosecond laser or Q-switched laser: differences, uses and selection
Picosecond laser or Q-switched laser: both shatter tattoo ink and pigment with ultrashort pulses, but with differing fineness, with differing amounts of heat and in very different price brackets. This page compares pulse duration, photoacoustic and photothermal effect, tattoo colours, number of sessions, skin reaction and use for pigment spots, melasma and skin rejuvenation.
SIACSKIN offers both technologies: the PICOLO XL as a picosecond laser with 280 ps, and the PICOLO L and the PICOLO S as Q-switched Nd:YAG lasers in the nanosecond range. This lets you see which type of laser suits your treatments and when the extra cost of picoseconds pays off.
Does a picosecond laser work photoacoustically and a Q-switched laser photothermally?
Not quite: both lasers shatter pigment by means of a pressure wave, and the difference lies in the ratio of mechanical to thermal effect. A Q-switched laser delivers its energy in a few nanoseconds. That is enough for the photoacoustic effect, but part of the energy flows into the surrounding tissue as heat. With picosecond pulses, the energy has been delivered before the particle can expand or give off heat. The effect is almost purely mechanical, and the pigment breaks down more finely.
Such lasers only work predominantly photothermally in Long Pulse mode. At SIACSKIN, the PICOLO XL is the picosecond laser with 280 ps, while the PICOLO L and the PICOLO S are Q-switched Nd:YAG lasers in the nanosecond range.
How much shorter is a picosecond pulse than a nanosecond pulse and what does that change for the pigment?
A picosecond is one thousandth of a nanosecond, and in practice picosecond pulses are about 10 to 30 times shorter than the pulses of a Q-switched laser. Q-switched lasers typically work with about 5 to 10 nanoseconds, picosecond lasers with a few hundred picoseconds. What matters is how the pulse duration matches the particle size: tattoo pigments are so small that they release heat and pressure again in less than one nanosecond. If the pulse is shorter than this time, stress builds up in the particle until it shatters. Longer pulses are more likely to heat it up.
The PICOLO XL from SIACSKIN works with 280 ps. The PICOLO L and the PICOLO S are Q-switched Nd:YAG lasers with pulses in the nanosecond range.
What does peak power mean and why is it higher in a picosecond laser than in a Q-switched laser?
Peak power is the pulse energy divided by the pulse duration, and because the picosecond pulse is much shorter, it rises many times over at the same energy. A worked example: 500 mJ in 5 nanoseconds gives 100 megawatts, while the same 500 mJ in 280 picoseconds gives around 1.8 gigawatts. This power hits the pigment abruptly and shatters it instead of heating it. The wattage on the data sheet, by contrast, describes the device as a whole and says little about the individual pulse.
You should therefore always compare pulse duration and energy per pulse together. The PICOLO XL is specified with 280 ps and 100 to 3600 mJ, the PICOLO L with up to 1800 mJ at 1064 nm and up to 500 mJ at 532 nm.
For which tattoo colours is the picosecond laser superior to the Q-switched laser and where is it not?
The picosecond laser has its greatest lead with green, blue, turquoise and other stubborn colours, while the difference is smallest with black tattoos. Black absorbs 1064 nm so well that nanosecond pulses also break it down reliably. Coloured pigments absorb more weakly and are often very fine-grained, and here the stronger mechanical effect of short pulses achieves more. Red and orange respond well to both laser types at 532 nm. White, yellow and skin tones remain difficult for both.
In addition, the wavelength must match the colour. The PICOLO XL combines 280 ps with 532, 755, 1064 and 1320 nm, optionally with a Dye-Head for 585 and 650 nm. With 1064 and 532 nm, the PICOLO L covers black, dark shades, red and orange.
Does a picosecond laser really save sessions compared with a Q-switched laser?
Yes, often, but not to the same extent with every tattoo. In tattoo removal, 4 to 8 sessions at intervals of 6 to 8 weeks are usual, and with picosecond pulses the number tends to be at the lower end of this range. The saving is clearest with colourful, dense and previously treated tattoos. With a thinly inked black amateur tattoo, a Q-switched laser also reaches the goal in a few sessions. Colour, ink depth, body site and immune system determine the course more strongly than the laser type alone, and nobody can promise a fixed number in advance.
For the Q-switched laser PICOLO L, SIACSKIN itself states slightly more sessions than for the PICOLO XL, but in return it is more economical to purchase.
Does a picosecond laser help when a tattoo no longer responds to the Q-switched laser?
Often yes: if a tattoo barely gets any lighter after several Q-switched laser sessions, switching to picosecond pulses frequently brings progress again. With every session the remaining particles become smaller. The smaller the particle, the shorter the pulse has to be in order to shatter it. Nanosecond pulses increasingly do no more than heat such remnants. A second reason is colours for which the right wavelength was previously lacking, such as green or blue.
It remains difficult when the standstill is due to scar tissue or to pigment that has darkened, in which case every technique reaches its limits. With 280 ps and four wavelengths, the PICOLO XL is designed for multicoloured and deep-seated tattoos and is therefore the right device for such cases.
How does the skin reaction differ after a picosecond laser and a Q-switched laser?
After both lasers the area first turns whitish, then red and swollen, but the reaction is usually milder after the picosecond laser. Because less heat passes into the surrounding tissue, large blisters and thick crusts occur less often. After nanosecond pulses, small blisters, pinpoint bleeding and crusts are more common, especially with high energy and dense ink. In both cases the skin has healed superficially after about 1 to 2 weeks, and the interval of 6 to 8 weeks until the next session stays the same.
The risk of light or dark spots depends above all on skin type, wavelength and energy. On the PICOLO XL and the PICOLO L, the SIA AI sets the parameters automatically, while you assess the reaction after the test pulse yourself.
Does treatment with a picosecond laser hurt less than with a Q-switched laser?
The difference is small: both lasers feel like a rubber band snapping against the skin, and many people perceive picosecond pulses as slightly shorter and less burning. How much it stings depends more on energy, spot size, ink density and body site than on the laser type. Over bone and on thin skin it is uncomfortable with both devices. The burning sensation afterwards is often shorter after the picosecond laser because less heat remains in the tissue. You achieve the most through cooling and, if required, a numbing cream before the session.
The KYROMASTER cools the skin with cold air down to minus 50 °C before, during and after the pulses. It is suitable for picosecond and Nd:YAG lasers, in other words for the PICOLO XL just as much as for the PICOLO L and the PICOLO S.
Which pigment does the Q-switched laser treat well and where does the picosecond laser have the advantage?
Both laser types treat superficial pigment such as freckles and sun spots well, while the picosecond laser has the advantage with deep-lying pigment and with skin that darkens easily. Spots in the epidermis absorb 532 nm strongly and flake off after about 5 to 10 days, and 1 to 3 sessions are usually enough. Pigment in the dermis needs 1064 nm and more sessions, and here shorter pulses break the granules down more finely. With spots following inflammation, heat is the problem: the less of it remains in the tissue, the lower the risk of new spots forming.
The PICOLO XL lists pigmentation disorders as an application and works with 280 ps. With 532 and 1064 nm, the PICOLO L covers both depths in the nanosecond range. For occasional pigment treatments the PICOLO S is sufficient.
Picosecond laser or Q-switched laser for melasma: which is the more cautious choice?
The more cautious option is the laser that manages with less heat, and with a comparable effect that is usually the picosecond laser. Melasma responds to heat and inflammation with new pigment. For this reason, treatment is carried out with 1064 nm, a large spot and very low energy over several sessions, known as laser toning. This can be done with Q-switched and with picosecond lasers. With both, excessive energy or intervals that are too short can lead to patchy lightening or a relapse. No laser eliminates the cause, and sun protection and maintenance treatment are always part of the plan.
The PICOLO XL and the PICOLO L list melasma as an application. As a non-ablative alternative with 1927 nm, SIACSKIN offers the TULIX.
Improving complexion and pores: is a Q-switched laser enough or does it take picoseconds?
For finer pores, less sebum and a fresher skin tone a Q-switched laser is enough, while for an effect on skin structure at depth the picosecond laser has the advantage. Here the Q-switched laser works at the surface: with a carbon peel and with gentle toning at low energy, and 3 to 6 sessions every 2 to 4 weeks are usual. Fractional picosecond pulses concentrate the energy onto many small points and create stimuli beneath the intact epidermis that trigger collagen remodelling. This is aimed more at fine lines and uneven texture.
For carbon peels, the PICOLO S and the PICOLO L are the right devices, and the PICOLO L additionally comes with Genesis mode for skin rejuvenation. The PICOLO XL also offers 755 nm in a Honeycomb version.
Why do picosecond lasers and Q-switched lasers also have a Long Pulse mode?
Long Pulse mode turns the pigment laser into a tool for gentle heat: the pulse is much longer and warms the tissue instead of shattering particles. Without Q-switching, the laser delivers its energy over a considerably longer period. Peak power drops, there is no pressure wave, and the heat spreads evenly in the dermis. This is used for skin rejuvenation treatments in which collagen is to be stimulated and the complexion is to become more even. This mode is not intended for tattoos and pigment spots.
Alongside Pico mode, the PICOLO XL offers a Long Pulse mode. The PICOLO L supplements Q-switched operation with Long Pulse and Genesis mode for skin rejuvenation.
Why does a picosecond laser cost more than a Q-switched laser and how big is the difference?
A picosecond laser is more expensive because generating and amplifying such short pulses is technically far more complex than the Q-switching of a nanosecond laser. The laser source and optics have to withstand very high peak powers, and there are usually more wavelengths as well. At SIACSKIN you can see the gap in the instalments: the PICOLO XL from approx. €1,000/month, the PICOLO L from approx. €690/month, and the PICOLO S as the entry level from approx. €130/month.
As a guide, leasing comes to around 1% of the net price per month over a term of 60 months, plus VAT and depending on creditworthiness. The current net prices are shown on the product pages.
From what treatment volume is a picosecond laser worthwhile instead of a Q-switched laser?
A picosecond laser is worthwhile as soon as tattoo and pigment treatments are an established focus and many colourful or previously treated tattoos come in. Then shorter courses of treatment and the ability to take on difficult cases are what count. If tattoo lightening, pigment and carbon peels only run alongside the main business, a Q-switched laser with its lower instalment is easier to sustain. Work it out with your own figures: sessions per month, price per session and instalment.
At SIACSKIN this means: the PICOLO S for getting started with a small volume, the PICOLO L for regular treatments, the PICOLO XL for practices and clinics with a focus on tattoo removal. The price calculator helps you set the instalment against your treatment numbers. Who is permitted to carry out which treatment is regulated differently from country to country.
Have Q-switched lasers been made obsolete by the picosecond laser?
No, Q-switched lasers remain the standard and are the more sensible choice for many businesses. Black and dark tattoos, lightening before a cover-up, age spots and carbon peels are achieved reliably with nanosecond pulses. The technology has been proven for decades and is considerably less expensive. The picosecond laser plays to its strengths where things get difficult: coloured inks, deep-seated or previously treated tattoos, sensitive skin and demanding pigment treatments. Both technologies have their place, and what matters is your treatment mix.
That is why SIACSKIN carries both: the PICOLO L and the PICOLO S as Q-switched Nd:YAG lasers and the PICOLO XL as a picosecond laser with 280 ps.
