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Technology · Target: water

How do erbium lasers work in the skin?

Erbium lasers have a wavelength of 2940 or 2910 nm and target water. Their light is absorbed in a very thin layer, so they can vaporise tissue precisely: across the whole surface or in a grid of narrow channels reaching into the dermis. We supply DualMode and UltraClear, which vaporise tissue, and Mosaic 3D, a non-ablative Er:glass laser at 1550 nm.

Clinically reviewed by Marit van Boldrik, Business & Clinicallast checked 19 October 2026

Translated from Dutch with the help of AI tools; the clinical review was carried out on the Dutch text.

What is erbium?

Erbium is the element that generates the light in the laser source. It is contained in a crystal (Er:YAG), in glass (Er:glass) or in an optical fibre, and emits light at around 2940, 2910 or 1540–1550 nm. Water absorbs all of these wavelengths, but not equally strongly. Around 2940 nm, water absorbs the light so strongly that the energy stays in the top few micrometres of tissue. At 1540–1550 nm, water absorbs more than a thousand times less and the light reaches deeper [1].

So the wavelength determines how deep the energy is absorbed. Whether the tissue then vaporises (ablative) or only coagulates (non-ablative) depends on the energy and the pulse. An Er:YAG laser vaporises with short, powerful pulses, but is also used non-ablatively [2]. In practice, Er:glass at 1550 nm is used non-ablatively and fractionally.

Two of our devices work ablatively with erbium: DualMode, an Er:YAG handpiece (2940 nm) for the Etherea MX platform, and UltraClear, an erbium fibre laser (2910 nm). Mosaic 3D uses Er:glass at 1550 nm and works non-ablatively. FlexSys also has a non-ablative 1550 nm module, but there the light comes from a diode laser. These 1540–1550 nm lasers form a group of their own and are covered only briefly here.

Vaporising tissue with little heat around it

Water absorbs most strongly around 2940 nm [1]. If the pulse is short and powerful enough, the thin layer in which the light is absorbed vaporises almost instantly. Little heat is then left to leak into the surrounding tissue. Each pulse removes a thin layer, and the next one continues working in that opening. In an early in vitro study on porcine skin, thermal necrosis around the opening was at most 50 micrometres [3].

Because there is so little coagulation, small blood vessels start to bleed as soon as the treatment reaches the dermis [3]. That is why some erbium lasers deliver a coagulating component alongside the ablative pulse: energy that heats the tissue without vaporising it. This lets you set the balance between vaporisation and coagulation [4][5]. According to Vydence, DualMode combines ablation and coagulation in a single pulse. UltraClear also lets you set the coagulation, with its own pulse structure [6].

Absorption by water between 2550 and 3350 nm on a linear scale. The curve peaks at around 2940 nm, where DualMode works; UltraClear at 2910 nm sits just slightly lower on the same peak. A dotted line shows the much lower level at 10,600 nm, the CO₂ wavelength.
At room temperature, water absorbs light at 2910 and 2940 nm almost equally strongly. In heated tissue, that absorption changes.

Fractional or full-surface

An ablative erbium laser can treat the whole surface or a grid of small zones. Across the full surface, the laser removes the skin layer by layer: the classic laser peel. This also removes superficial benign lesions [3], such as seborrhoeic keratoses and flat warts [11].

A fractional treatment creates narrow channels into the dermis, with intact skin in between. This spreads the effect: you need more treatments, but each one means less downtime and a lower risk of complications [12]. DualMode has fractional lenses for this, as well as spots for full-surface treatment. UltraClear works mainly fractionally, with microbeams in a scanned grid [9]. According to Acclaro, it also has a full ablation mode.

Erbium alongside CO₂ and non-ablative lasers

For resurfacing, the obvious comparison is with CO₂, in our range the eCO2 3D. Water absorbs CO₂ light about fifteen times less strongly than erbium light at 2940 nm, so more heat remains around each opening with CO₂ [1]. A 2026 meta-analysis pooled five comparative studies in atrophic acne scars, with 130 participants in total. With fractional CO₂, more patients achieved an improvement of over 50% than with fractional erbium lasers (Er:YAG or Er:glass). CO₂ did, however, cause more pain, and downtime was on average almost four days longer. When the authors counted only the randomised studies, the direction stayed the same, but the difference was no longer significant. For post-inflammatory hyperpigmentation (PIH), they found no significant difference, but the numbers were small [13].

For wrinkles, the comparisons are older and concern non-fractional treatments. In one study, the researchers treated one side of the periorbital or perioral area with CO₂ and the other with Er:YAG, aiming for a comparable treatment depth on both sides. Recovery was almost the same, but CO₂ worked better on moderate and deep wrinkles [14].

Ablative and non-ablative erbium have also been compared with each other. At 1550 nm the light vaporises nothing: it coagulates narrow columns of tissue into the dermis, while the stratum corneum stays intact [15]. Without open wounds, the skin recovers faster, although ablative lasers usually have a greater effect [12]. A randomised study in Asian patients with photoageing compared three sessions of fractional Er:YAG with three sessions of fractional 1550 nm Er:glass. Pigment, uneven skin tone and redness improved more with Er:YAG; wrinkles and overall appearance improved more with Er:glass. In this study, the ablative Er:YAG caused less pain and fewer side effects. The authors see the two as complementary treatments [16].

Thulium (1927 nm, in the LaseMD Ultra) works non-ablatively and more superficially, mainly in the epidermis and upper dermis. In a split-face study in acne scars, fractional thulium and fractional Er:YAG gave comparable improvement after three sessions [17].

What it is used for

  • Skin rejuvenation

    Skin rejuvenation concerns changes deeper in the dermis, such as wrinkles and advanced photoageing. An ablative erbium laser works there with fractional channels that reach into the dermis. In a study with the 2910 nm erbium fibre laser, patients with advanced photoageing received three treatments of the face and neck. The 15 participants who completed the study improved moderately to markedly, according to the authors, with five to seven days of redness, swelling and crusting. There was no control group [18].

  • Skin quality improvement

    Skin quality improvement concerns fine lines, a dull or rough texture and superficial pigment. A superficial, fractional ablative erbium treatment mainly renews the epidermis, with little downtime [9][19]. In a randomised comparison in Asian patients, pigment, uneven skin tone and redness improved more with fractional Er:YAG, and wrinkles and overall appearance more with non-ablative 1550 nm Er:glass [16].

  • (Acne) scars

    In atrophic scars, such as acne scars, the aim is remodelling in the dermis. Ablative erbium reaches the dermis through narrow channels. Er:YAG with a coagulating component improved acne scars, including in skin types III and IV [4][5]. The 2910 nm erbium fibre laser also improved acne scars, in skin types II to IV [6][8]. In a meta-analysis, fractional CO₂ more often gave over 50% improvement than fractional erbium lasers (Er:YAG and non-ablative Er:glass combined), with more pain and longer downtime [13].

  • Wrinkles

    For fine wrinkles, ablative erbium works by resurfacing; for deeper wrinkles, through channels into the dermis. In an older comparison of non-fractional treatments, CO₂ worked better than Er:YAG on moderate and deep wrinkles around the eyes and mouth [14]. In a randomised study, wrinkles improved more with non-ablative 1550 nm Er:glass than with fractional Er:YAG [16]. Advanced photoageing with wrinkles improved with the 2910 nm erbium fibre laser [18].

  • Pigmentation

    Ablative erbium can reduce mainly superficial, epidermal pigment, because the epidermis is renewed. In a randomised comparison in Asian patients with photoageing, pigment and uneven skin tone improved more with fractional Er:YAG than with non-ablative 1550 nm Er:glass [16]. Melasma calls for its own approach; see the melasma page.

  • Benign skin lesions

    Full-surface Er:YAG removes superficial lesions layer by layer [3]. In a series of more than three thousand patients, these included seborrhoeic keratoses, flat warts and xanthelasma, with a short recovery time [11]. In deeper lesions, bleeding can hinder treatment, and the authors saw scarring after healing [3]. Acclaro also lists UltraClear for benign keratoses, in a fractional mode. Vaporised tissue can no longer be examined histologically. Laser ablation is therefore only an option once the diagnosis is certain.

  • Stretch marks

    In stretch marks, the aim is to remodel the collagen in the dermis [20]. In a study of 20 patients, one half of the abdomen received fractional Er:YAG and the other fractional radiofrequency. The stretch marks improved on both sides, with no significant difference between the two [21]. In skin types III and IV, a pilot study with Er:YAG resurfacing saw temporary PIH that could last up to six months [20].

Pigment risk and recovery

Skin type is a major factor in choosing an erbium treatment. Erbium targets water, not melanin, so skin colour does not determine where the light is absorbed. Even so, PIH remains the main risk in dark skin, because the melanocytes there are more active and respond more strongly to the inflammation that follows a treatment. A review article on aesthetic treatments in dark skin advises against using high energy, delivering multiple pulses in quick succession on the same spot, or scheduling sessions close together [22].

In dark skin, PIH is the main point to watch. A study of fractional Er:YAG with a coagulation mode in skin types III and IV found PIH in 3% of patients [5]. In Er:YAG resurfacing of stretch marks in skin types III and IV, temporary PIH was the most common side effect, sometimes lasting up to six months [20]. The acne scar study with the 2910 nm fibre laser included only participants with skin types II and III [8]. In a series of 15 patients with scars, skin types II to IV, the authors saw no PIH after one treatment [6]. In the study on advanced photoageing with the same laser, there were two cases of temporary hyperpigmentation among 15 participants [18]. Acclaro describes UltraClear as suitable for all skin types; in skin types V and VI, extra caution is advisable.

In a pilot study with light and deeper settings of the 2910 nm fibre laser, redness, swelling and pinpoint bleeding lasted up to five days [19]. After three treatments of the face and neck for advanced photoageing, there was also crusting, and the reactions lasted five to seven days [18].

What the studies show

Er:YAG, 2940 nm (DualMode)

Er:YAG has been used in dermatology since the 1990s, and there is extensive clinical experience with it [3][11]. In studies, Er:YAG with a combined ablative and coagulating mode, as offered by DualMode, improved acne scars, among other conditions [4][5].

Erbium fibre laser, 2910 nm (UltraClear)

Since 2023, studies of UltraClear with 14 to 37 participants have been published [6][8][9][18][19]. They report improvement in photoageing and scars, with temporary side effects. Acclaro describes the results as comparable to CO₂, with less downtime.

Our devices using this technology

UltraClear erbium fibre laser device for skin rejuvenation and resurfacing, with a modern touchscreen interface and medical treatment arm.
Acclaro

UltraClear

Skin quality improvementSkin rejuvenationSkin tightening+5
DualMode Er:YAG laser handpiece with fractional technology for skin rejuvenation, resurfacing and the treatment of scars and pigmentation.
Vydence Medical

DualMode

Skin rejuvenation(Acne) scarsPigmentation+3
MOSAIC 3D laser treatment device with touchscreen and flexible laser head on a mobile base.
Cynosure Lutronic

Mosaic 3D

Skin quality improvementSkin rejuvenationSkin tightening+4

Advice

Is this technology right for your practice?

A single page cannot fully cover the choice between technologies. It depends on your patients and their skin types, the indications you want to treat, the recovery time your patients will accept and the equipment you already have. Our clinical and sales specialists have years of experience with that choice and are glad to help you make it.

Already working with one of our devices? You will find the treatment protocols and guidelines on the customer portal, and we go deeper into technique in the training after delivery and at our Academy events.

Schedule a conversationGo to the customer portal

This is an indicative overview to explain how technologies differ. Actual settings are governed by the treatment protocols and guidelines.

References

  1. Hale GM, Querry MR. Optical constants of water in the 200-nm to 200-µm wavelength region. Appl Opt. 1973;12(3):555–563. doi:10.1364/AO.12.000555Diagram: D. J. Segelstein (1981), via S. Prahl, Oregon Medical Laser Center (https://omlc.org/spectra/water/).
  2. Tian B. Treatment of freckles using a fractional nonablative 2940nm Erb:YAG laser in a series of Asian patients. J Clin Aesthet Dermatol. 2017;10(8):28–30. https://pmc.ncbi.nlm.nih.gov/articles/PMC5605211/
  3. Kaufmann R, Hibst R. Pulsed Erbium:YAG laser ablation in cutaneous surgery. Lasers Surg Med. 1996;19(3):324–330. doi:10.1002/(SICI)1096-9101(1996)19:3<324::AID-LSM7>3.0.CO;2-U
  4. Tanzi EL, Alster TS. Treatment of atrophic facial acne scars with a dual-mode Er:YAG laser. Dermatol Surg. 2002;28(7):551–555. doi:10.1046/j.1524-4725.2002.01319.x
  5. Hu S, Hsiao WC, Chen MC, Huang YL, Chang SL, Shih PY, Gold MH. Ablative fractional erbium-doped yttrium aluminum garnet laser with coagulation mode for the treatment of atrophic acne scars in Asian skin. Dermatol Surg. 2011;37(7):939–944. doi:10.1111/j.1524-4725.2011.02009.x
  6. Murray TN, Guo EL, Richmond H, Friedman PM. Single treatment scar resurfacing with a novel ablative fractional 2910 nm erbium-doped fluoride glass fiber laser. Lasers Surg Med. 2024;56(1):19–22. doi:10.1002/lsm.23729Retrospective series; one author sits on Acclaro's medical advisory board.
  7. Shori RK, Walston AA, Stafsudd OM, Fried D, Walsh JT. Quantification and modeling of the dynamic changes in the absorption coefficient of water at λ = 2.94 μm. IEEE J Sel Top Quantum Electron. 2001;7(6):959–970. doi:10.1109/2944.983300
  8. Bernstein E, Alajmi A, Wang J, Hochman E, Biesman B, Sanzo JF. The 2910-nm fiber laser is safe and effective for improving acne scarring. Lasers Surg Med. 2024;56(9):755–761. doi:10.1002/lsm.23845
  9. Bernstein EF, Sanzo JF, Wang JY, Cotsarelis SM, DiLeonardo M. Low-fluence treatment with a novel fractionated 2,910-nm fiber laser improves photodamage. Lasers Surg Med. 2023;55(1):35–45. doi:10.1002/lsm.23624
  10. Murray TN, Maredia H, Friedman PM. Histological analysis of laser-enabled tissue coring with a novel 2910 nm erbium-doped fluoride glass fiber laser. Lasers Surg Med. 2024;56(5):462–465. doi:10.1002/lsm.23792
  11. Nisticò SP, Cannarozzo G, Campolmi P, Dragoni F, Moretti S, Patruno C, Bennardo L. Erbium laser for skin surgery: a single-center twenty-five years' experience. Medicines (Basel). 2021;8(12):74. doi:10.3390/medicines8120074
  12. Preissig J, Hamilton K, Markus R. Current laser resurfacing technologies: a review that delves beneath the surface. Semin Plast Surg. 2012;26(3):109–116. doi:10.1055/s-0032-1329413
  13. Song X, Zhi BW. Comparative efficacy and safety of fractional carbon dioxide and erbium-based fractional lasers for atrophic acne scars: a systematic review and meta-analysis. Lasers Med Sci. 2026;41:222. doi:10.1007/s10103-026-05022-z
  14. Adrian RM. Pulsed carbon dioxide and erbium-YAG laser resurfacing: a comparative clinical and histologic study. J Cutan Laser Ther. 1999;1(1):29–35. doi:10.1080/14628839950517066
  15. Manstein D, Herron GS, Sink RK, Tanner H, Anderson RR. Fractional photothermolysis: a new concept for cutaneous remodeling using microscopic patterns of thermal injury. Lasers Surg Med. 2004;34(5):426–438. doi:10.1002/lsm.20048
  16. Moon HR, Yun WJ, Lee YJ, Lee MW, Chang S. A prospective, randomized, double-blind comparison of an ablative fractional 2940-nm erbium-doped yttrium aluminum garnet laser with a nonablative fractional 1550-nm erbium-doped glass laser for the treatment of photoaged Asian skin. J Dermatolog Treat. 2015;26(6):551–557. doi:10.3109/09546634.2014.999020
  17. Lu K, Cai S. Efficacy and safety comparison between 1927 nm thulium laser and 2940 nm Er:YAG laser in the treatment of facial atrophic acne scarring: a prospective, simultaneous spilt-face clinical trial. Lasers Med Sci. 2022;37(3):2025–2031. doi:10.1007/s10103-021-03465-0
  18. Murray TN, Hu JK, Friedman PM. Full-face and neck resurfacing with a novel ablative fractional 2910 nm erbium-doped fluoride glass fiber laser for advanced photoaging. Lasers Surg Med. 2024;56(3):249–256. doi:10.1002/lsm.23764
  19. Selim MM, Lowery JA, Maredia HS, Zelickson BD. Clinical evaluation of a new fractional ablative 2910 nm erbium laser on photodamaged skin: a pilot study. Lasers Surg Med. 2023;55(8):715–723. doi:10.1002/lsm.23714
  20. Wanitphakdeedecha R, Meeprathom W, Manuskiatti W. A pilot study of treatment of striae distensae with variable square pulse Erbium: YAG laser resurfacing. J Cosmet Dermatol. 2017;16(4):466–470. doi:10.1111/jocd.12391
  21. Shen J, Jin JJ, Huang JH, Wang HW, Shi L. Efficacy and safety of bipolar fractional radiofrequency vs. 2940-nm Er:YAG ablative fractional laser in striae distensae treatment: A split abdomen study. J Cosmet Dermatol. 2024;23(6):2022–2029. doi:10.1111/jocd.16243
  22. Harnchoowong S, Vachiramon V, Jurairattanaporn N. Cosmetic considerations in dark-skinned patients. Clin Cosmet Investig Dermatol. 2024;17:259–277. doi:10.2147/CCID.S450081
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