Technology
What does 10,600 nm mean? The CO₂ wavelength explained for buyers
Why the 10,600 nm CO₂ wavelength targets tissue water, what that means for ablation and coagulation, and how it differs from pigment lasers and IPL.
Every CO₂ laser brochure leads with the same number: 10,600 nm. It is easy to treat it as a label. For a buyer, it is the single most important fact about the platform, because the wavelength decides what the laser interacts with in tissue — and therefore what it can and cannot do.
A wavelength is a choice of target
Lasers deliver light at one wavelength. Different molecules in tissue — called chromophores — absorb different wavelengths. Choose the wavelength and you largely choose the target.
- Pigment lasers are chosen for melanin or tattoo ink.
- Vascular lasers and IPL filters target haemoglobin.
- 10,600 nm (10.6 µm), the CO₂ laser wavelength, is very strongly absorbed by water.
Skin and soft tissue are water-rich. At 10,600 nm the energy is absorbed in a thin surface layer and converted to heat almost immediately. That is why CO₂ behaves as a precise surface-resurfacing and soft-tissue tool: the effect is concentrated where the beam lands rather than scattered deep into tissue.
Two effects from one wavelength
Because the mechanism is photothermal — controlled heat, not a shockwave — every CO₂ pass produces a blend of two tissue effects.
| Effect | What happens | Why a clinic cares |
|---|---|---|
| Ablation (vaporization) | Tissue water flashes to vapour and a micro-volume of tissue is removed | The resurfacing and cutting effect |
| Coagulation | Heat spreading from the ablated zone denatures protein and seals small vessels | Drives collagen remodeling; hemostatic support in soft-tissue work |
More energy, longer dwell time and denser delivery push the balance toward deeper ablation and a wider coagulation zone: more correction, but more recovery. Lighter, faster, less dense delivery favours a shallow effect with a thin coagulation rim. The operator controls that balance — which is why training matters as much as hardware.
Why 10,600 nm needs special delivery
Light at 10,600 nm does not travel through the standard silica fibers used by many diode and Nd:YAG systems. CO₂ platforms therefore use articulated arms, hollow waveguides or other specialized delivery systems.
Alexa CO₂ Aesthetic uses a 7-joint, weight-balanced articulated arm with a 130 cm working radius. The beam travels through air from mirror to mirror, which supports beam quality and consistent delivered power, with no disposable fiber for standard procedures. Like any optical path, the arm needs appropriate maintenance and output verification. The technology page shows the full platform.
Because the CO₂ beam is invisible, a visible aiming beam shows where energy will land; on Alexa it is a 650 nm red diode.
What the wavelength makes possible
Water targeting is what lets one CO₂ source support several categories:
- Fractional resurfacing — a grid of micro-columns for texture, lines, photoaging and acne scars.
- Ablative resurfacing — removal of a continuous layer for more intensive renewal.
- Soft-tissue procedures — focused for incision or excision, defocused for vaporization and coagulation of selected benign lesions after diagnosis.
- Specialty pathways — on Alexa, Alexa Femme™ for women’s health and Alexa Follicle™ for hair-restoration support, each with its own applicator and protocol.
Read how fractional and ablative delivery differ and how clinicians plan shallow, deep and hybrid resurfacing.
What the wavelength does not do
Being precise about limits protects both the practice and the patient.
- It is not a pigment laser. The target is water, not melanin. Pigment-focused programs belong on platforms built for that purpose.
- It is not skin-type neutral. Although water is the target, ablative injury causes inflammation, and in skin with more melanin that raises the risk of post-inflammatory hyperpigmentation. Ablative CO₂ is planned most conservatively as Fitzpatrick type rises, and pigment changes can appear days or weeks later.
- It does not set the dose by itself. Power, dwell, density, depth, passes and scan pattern define each treatment.
Questions to ask about wavelength and delivery
- Is the source a 10,600 nm CO₂ laser, and in which power configurations?
- How is the beam delivered, and what maintenance does that system need?
- What aiming beam is used?
- Which emission modes are available? (Alexa’s 40 W unit offers continuous, pulsed and superpulse modes.)
- How does training cover the balance between ablation and coagulation, and skin-type planning?
The takeaway
“10,600 nm” tells you the laser targets water. That single fact explains why CO₂ resurfaces, why it can cut and coagulate, why it needs an arm or waveguide, and why skin-type planning and training are non-negotiable. When you compare platforms, the wavelength is the starting point — delivery, control, training and service decide the rest.
For a structured comparison, read how to choose a professional fractional CO₂ laser or go straight to the buyer’s guide.