If you have researched acne-scar treatment, pore reduction, or scar improvement, you have probably heard of fractional lasers. Often described as a skin “eraser,” fractional technology represents a shift from broad tissue removal to precise micro-treatment.

Why Divide a Laser Beam?

The theory of selective photothermolysis established precise targeting of chromophores such as melanin and hemoglobin. In 2004, fractional photothermolysis was introduced to address the limitations of traditional resurfacing.

Traditional ablative lasers acted like a bulldozer: a continuous beam removed an entire surface area. Although effective, this could cause extensive injury, long recovery, pigment changes, and scarring. Fractional lasers divide one beam into thousands of microscopic columns, treating only tiny points while leaving surrounding skin intact.

Left: non-fractional; right: fractional distribution

Three Core Concepts

1. Microscopic Treatment Zones (MTZs)

Hundreds or thousands of microbeams create columns only about 100–400 μm wide. Within each column, old tissue is either vaporized by an ablative laser or coagulated by a non-ablative laser.

2. Untreated Tissue as a Repair Network

Normal tissue between the columns remains intact. These “skin bridges” contain active cells and growth factors that rapidly migrate into treated areas, shortening recovery from weeks to days.

3. MENDs: the Skin's Waste-Removal System

Microscopic epidermal necrotic debris packages melanin and damaged cells produced by treatment. These particles migrate toward the surface and shed naturally as tiny crusts, supporting renewal from within.

Ablative vs. Non-Ablative Fractional Lasers

Fractional systems fall into two main groups according to how they interact with the epidermis and dermis.

Understanding Wavelengths: Water Is the Target

Unlike pigment-selective Q-switched lasers, fractional resurfacing primarily targets water in skin. Water absorbs specific wavelengths and converts their energy into controlled heat.

Different wavelengths are absorbed by water to different degrees and therefore reach different depths.

Ablative wavelengths

2940 nm (Er:YAG): Extremely high water absorption produces superficial, precise ablation with limited surrounding heat, generally less discomfort, and faster recovery.

10,600 nm (CO₂): Lower water absorption than 2940 nm but deeper penetration and broader thermal spread. It offers stronger hemostasis and tightening, with a longer recovery period.

Non-ablative wavelengths

1440, 1540, 1550, and 1565 nm: Moderate water absorption allows dermal heating without removing the epidermis, making these wavelengths useful for wrinkles, pores, and texture.

1927 nm: A more superficial wavelength that acts in the epidermis and upper dermis and mildly disrupts the stratum corneum. Often described as sub-ablative or micro-ablative, it is useful for dullness and pigmentation.

Summary

Fractional lasers use controlled microscopic injury to stimulate broad skin repair. The best wavelength and laser type depend on the condition being treated and the acceptable downtime. Treatment should be selected with a qualified clinician.

The core founding team of Suzhou Foremed Legend Medical Technology Co., Ltd. comes from well-known domestic and foreign universities such Peking University. Foremed Legend is based on compliance and takes product power as the core, focusing on the design, research and development, and application of high-end medical and photoelectric equipment, committed to becoming the leading enterprise in the global high-end medical beauty and photoelectric equipment field, the provider of integrated intelligent solutions for diagnosis and treatment, the pioneer of medical beauty data integration platform.
By tackling a series of key underlying technologies, Foremed Legend has now independently developed a number of high-end medical devices, as picosecond laser treatment equipment, long-pulse laser treatment equipment, intense pulsed light treatment equipment, photoacoustic imaging skin detection equipment and cold air treatment equipment, and to focus on the research and development of core technologies of products, using better technical solutions to benefit the vast number of beauty seekers.

Adhering to the goodness of technology,umaili will work with industry and ecological partners to bring more safe and effective medical beauty and photoelectric equipment and integrated diagnosis and treatment solutions to the global medical beauty market