What is CO₂ laser tube

author: Ava Ji

CO₂ laser is a gas laser that uses CO₂ to generate laser radiation. Laser action is achieved by transitions between vibrational and rotational levels of molecules. Its construction is simple and the output of this laser is continuous. It developed earlier and its products are more mature. As one of the most widely used lasers, it widely used in materials processing, medical use, environmental measurement and other fields.

Structure of Co2 laser tube

What is Co2 laser tube

Figure 1: As Co2 laser tube structure diagram

Co2 laser tube typically consists of three parts (see Figure 1): outer tube (gas storage tube), cooling tube, and discharge tube. The raw glass materials of Yongli As series Co2 laser tube are all from German Schott, to make sure the laser tube a stable cavity structure.

The discharge tube can affect the output of the laser. And its length is proportional to the output power. It is filled with Co2 gas and other auxiliary gases (mainly He and N2). The discharge tube of Yongli As series adopting Yongli third-generation coating process, which can greatly enhance coating firmness and improve laser tube catalytic reduction performance.

The discharge tube is connected to the gas storage tube at both ends, that is, one end of the gas storage tube is connected with the discharge tube with a small hole, and the other end is connected with the discharge tube through the air-returning spring tube, so that the gas can circulate in the discharge tube and the gas storage tube.

The function of cooling tube is to cool the working gas and make the output power stable. Because the gas in the discharge tube has high thermal conductivity, it is necessary to ensure that the water flow of the water-cooled tube can effectively cool the working gas to avoid damage to the laser tube.

The resonant cavity is composed of a flat mirror and a focus mirror. The flat mirror  is generally based on optical glass and silicon (Si), using a large curvature flat-concave cavity. The focus mirror is generally made of germanium (Ge) and zinc selenide (ZnSe), which are infrared materials that can transmit 10.6um radiation, and are made of multilayer dielectric film on the surface. So laser oscillator generally at 10.6 µm.

Advantages of Co2 laser tube

  • The construction of CO2 laser is simple.
  • The output of Co2 laser is continuous.
  • High optical quality of the output beam, good coherence.
  • Narrow line width and stable operation.
  • High performance and low cost.
  • Suitable for a variety of non-metallic materials, such as acrylic, die-board, MDF, leather, wood, fabric, etc.
  • Yongli A6s and A8s Co2 laser tube are capable for thin metal with better performance.


Application of Co2 laser

  • Widely used in industrial areas such as for cutting, marking and engraving. 
  • Applied in surgery, medical cosmetology, to treat skincare problems, and to perform microsurgery.
  • Applied in textile industry,CO2 laser can cut cloth and engraving.