Powerful and Economical CO2 Lasers | Versatile Tools for Laser Marking

A CO2 laser marker is an industrial marking system that uses a carbon dioxide laser medium as its laser source. Electrical excitation of a CO2 gas mixture generates infrared laser light in the wavelength range of approximately 9.3–10.6 μm. This invisible infrared laser beam is focused onto the workpiece using lenses and mirrors, causing localized heating of the material’s surface. Depending on the material, the beam’s energy produces a wide variety of marking effects: vaporization or ablation of the surface (engraving), color change or foaming in plastics, and burning into organic materials. The result is permanent and precise markings (e.g., serial numbers, barcodes, 2D codes, logos) without the use of ink or other additives.

CO2 lasers operate in the mid-infrared range and are particularly well-suited for all materials that strongly absorb this laser light. These include numerous non-metallic materials such as plastics (e.g., PE, PP, PET, PVC), resins, rubber, glass, ceramics, wood, paper, cardboard, leather, and other organic materials (such as textiles or food). Painted or coated surfaces can also be marked effectively—for example, CO2 lasers can mark painted metals and anodized aluminum efficiently and with high contrast. Uncoated (bare) metals, on the other hand, absorb very little CO2 laser light and therefore cannot be marked directly—or can only be marked inadequately—without special pretreatment.

Modern CO₂ laser markers achieve very high marking speeds, making them ideal for high-throughput production lines. Depending on the laser power and optics, marking speeds of up to ~2,100 characters per second and line speeds of up to 900 meters per minute can be achieved. This allows clear codes and markings to be applied even on fast-moving production lines (“on-the-fly” marking) without interrupting production. In practice, the actual achievable speed depends on factors such as the material, marking content, desired depth/contrast, and laser power—however, CO2 lasers generally offer a very fast and efficient marking method.

Their wavelength lies in the infrared range between 9.3 and 10.6 μm.

Yes, but only under certain conditions. Pure (polished) metals strongly reflect the CO2 laser beam in the 10.6-µm range, so direct marking on bare metal is generally not possible. However, a CO2 laser can be used to mark metals that have an absorbent surface - for example, dark-painted or anodized metal parts. In such cases, the laser vaporizes the top layer of paint or oxide, revealing contrasting lettering. For direct engraving on unpainted metal (e.g., steel or aluminum), on the other hand, fiber lasers are usually used, since metallic materials absorb the shorter wavelength of fiber lasers (~1.06 µm) much more effectively.

CO2 marking lasers are used across various industries wherever non-metallic materials need to be marked. Key application areas include the automotive and supplier industries, medical technology (e.g., marking of devices and plastic housings), the electronics industry (marking of printed circuit boards and components), and the packaging and consumer goods industries. Typical applications include the permanent marking of plastics (switches, housings), marking of glass (beverage bottles, pharmaceutical containers), direct marking of packaging (cardboard boxes, films), and marking of organic materials (e.g., wood products, leather). Wherever fast, non-contact, and abrasion-resistant markings on such materials are required, CO2 lasers offer a proven solution.

CO2 laser markers produce high-resolution, razor-sharp markings, even with very small font sizes or intricate graphics. Thanks to precise beam focusing and high-quality optics, the markings remain clear and easily legible (e.g., machine-readable barcodes or DataMatrix codes). In addition, laser markings are generally extremely durable: they are abrasion-resistant and resistant to heat, chemicals, and uv light. This robustness makes CO2 laser markings ideal for use in demanding industrial environments where high-quality, long-lasting markings are required.

CO2 laser markers are designed for seamless integration into manufacturing systems. They can be operated either as stationary units at a workstation or as part of production lines (e.g., on conveyor belts). Many CO2 lasers offer various beam guidance options (e.g., 0° or 90° beam exit) and interchangeable focusing lenses for marking fields of different sizes, allowing them to adapt to the layout of the facility. Through standard interfaces (e.g., Ethernet TCP/IP, digital I/O for triggering/control), they can be integrated into existing control systems. In addition, models with IP54 protection or, optionally, even IP65 protection are available—enabling use even in dusty or humid environments (e.g., in pharmaceutical, food, or beverage production).

CO2 marking lasers require very little maintenance. Modern systems use air-cooled CO2 laser tubes that operate with virtually no maintenance. Unlike many conventional marking methods, they do not require consumables such as ink, labels, or ribbons—only electricity and, if necessary, compressed air for cooling or purging. This keeps operating costs low and eliminates downtime for material changes. Overall, CO2 laser markers are designed for high reliability in everyday industrial use and have proven themselves over the years thanks to their low maintenance and operating costs.

Industrial CO2 laser markers fall into Laser Class 4 because they emit high-energy, invisible infrared radiation that is hazardous to the eyes and skin. Therefore, strict safety measures must be followed. In practice, CO2 lasers are often operated inside enclosed laser safety enclosures or laser workstations (Laser Class 1) to protect operators from direct laser light. In addition, effective exhaust ventilation with suitable filters is necessary, as the laser process - particularly when marking plastics - can generate harmful vapors and fine dust particles. Users should comply with legal regulations (e.g., DIN EN 60825 for laser safety, occupational safety guidelines for air quality control) and employ trained personnel for operation and maintenance. When all safety measures are properly implemented and appropriate certified enclosures are used, the operation of a CO2 laser is safe and reliable.

The main difference lies in the laser beam source and the wavelength, which determine the suitability for different materials. CO2 lasers emit infrared light at ~10.6 μm, which is absorbed particularly well by organic and non-metallic materials (e.g., wood, paper, plastics, glass). Fiber lasers, on the other hand, generate laser light at 1064 nm and are therefore ideally suited for metals as well as many plastics containing laser-active additives. In practice, this means that CO2 lasers are primarily used for marking non-metals and coated materials - for example, in the packaging, electronics, automotive, and medical technology industries for plastics, glass, rubber, or coated surfaces. Fiber lasers, on the other hand, are the first choice for direct metal marking (steel, aluminum, precious metals, etc.) and are increasingly used in areas where deep marking or maximum precision on metal is required (e.g., medical technology, tool and machine manufacturing, aerospace, and the automotive industry).