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CO2 Laser Marking

On this page, we explain marking examples and characteristics of CO2 laser markers, which are perfect for applications such as marking resin and paper or processing films.


CO2 lasers have the longest wavelength of all commonly used lasers, more than ten times longer than that of standard wavelength lasers.
In addition to paper and resin, it is also possible to mark wood, rubber, and transparent materials such as glass and PET plastic thanks to its heat-based marking method. On the other hand, it is hard to mark metal because the laser light has almost no reaction (is not absorbed).

Light wavelength distribution map
Ultraviolet range
Visible range
Infrared range
  • Cartons
  • Bottles
  • Design marking
    Design marking
  • Glass wafers
    Glass wafers
  • Weatherstripping
  • Electronic PCBs
    Electronic PCBs

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Mechanism and Characteristics of CO2 Lasers

CO2 lasers are gas lasers that use CO2 gas as their medium. CO2 gas is filled and enclosed in the discharge tube where the electrodes used for electrical discharge are arranged. Plasma is generated within the gas by an electrical discharge, and the generated light is amplified as it travels back and forth between the total reflective mirror and the output coupler and is output as the laser.

Mechanism and Characteristics of CO2 Laser
Total reflective mirror
CO2 gas
Output coupler

Feature: CO2 lasers can also be used for cutting applications

CO2 lasers use heat on the target, which allows use for cutting applications such as cutting holds, gate cutting, and sticker half cutting in addition to marking. Compared to mechanical cutting using cutting tools, CO2 laser cutting has the advantage of preventing quality deterioration based on tool wear and being maintenance free.

  • Film cutting and hole cutouts
    Film cutting and hole cutouts
  • Gate cutting
    Gate cutting
  • Sheathing cutting
    Sheathing cutting


Improving quality with short-wavelength and thin laser types

KEYENCE offers a product lineup including short-wavelength and thin laser types for improved quality of CO2 laser marking. Each type offers the following advantages.

Conventional methods

Conventional methods

Damage is excessive and engravings are deep and rough




Damage is minimal and engravings are shallow and sharp

9.3 μm short wavelength model
The wavelength of the ML-Z Series’ laser is available at 10.6 μm as well as a shortened 9.3 μm to better suit the heat absorption characteristics of resin. With a higher absorptivity in resin, this shorter wavelength allows for more precise marking with shallower engraving and less surface swelling.

Marking on PET bottles

Standard wavelength laser
Standard wavelength CO2 laser marker
Short-wavelength laser
Short-wavelength CO2 laser marker
  • Standard model
    Standard model
  • Thin laser model
    Thin laser model
Power density
Thin laser type
Compared to standard models, the laser spot diameter is smaller, enabling even finer marking. In addition, the smaller spot diameter allows for greater power density, which in turn allows for more efficient processing such as cutting and drilling.

Marking on IC chips

Conventional methods
Conventional methods
Thin laser
Thin laser

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Product Introduction

World’s first 3-axis control

World’s first 3-axis control3-Axis CO2 Laser MarkerML-Z Series

3-axis control
The focal distance can be varied over a 42 mm 1.65" range, reducing installation costs and enabling precise marking and processing that fits the product shape exactly.
30 W high power
This reduces the marking processing time and enables clear and stable marking even when products move at high speed.
300 mm (11.81") wide area
A wide area of 300 x 300 mm 11.81" × 11.81" is fully covered by a single unit, simplifying installations and reducing processing time.

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