The differences between RF CO2 laser and glass tube CO2 laser

Laser source is the core component of laser marking/engraving/cutting machines, The type and quality of the laser directly determine the processing quality of the laser equipment. CO2 laser marking/engraving/cutting machines have glass tube CO2 lasers and RF CO2 lasers. What are the differences between these two types of laser tubes?

1. Structure and materials are different:

• The glass tube CO2 laser, uses a laser tube made of glass material, filled with CO2 mixed gas inside. Its excitation method is usually direct current high-voltage discharge or alternating current high-frequency discharge.

• The RF CO2 laser uses a fully metal sealed RF-excited CO2 laser tube, filled with a mixture of CO2, nitrogen, and helium gases inside, and is excited by a radio frequency electromagnetic field to generate laser. 

2. Different beam qualities

• The beam quality and focusing performance of the glass tube CO2 laser are poor. The beam spot is large and not uniform, which is not suitable for applications requiring high precision.

• The laser beam spot pattern produced by the radio frequency CO2 laser is better, approaching the TEM00 mode. Under this mode, the beam spot is round and uniform, the beam focusing performance is excellent, the beam spot diameter is small and the divergence angle is small, and it is suitable for occasions requiring precise processing.

3. Different in lifespan and stability

• Glass tube CO2 laser tube: Poor power stability and reliability. Short lifespan. Depending on the usage frequency, the lifespan ranges from 3 months to 12 months. It cannot be refilled and requires a new glass tube to be replaced. Therefore, it is a consumable item.

• RF CO2 laser: Good stability, long lifespan, and maintenance-free type. The gas can be refilled repeatedly without the need to replace the laser tube. It should be noted that dust and particles in the working environment will splash onto the output mirror of the laser tube, causing local overheating and ablation of the laser output mirror. Whether it is a fan-cooled or water-cooled laser, during use, dust needs to be avoided to increase the lifespan of the radio frequency laser. 

4. Disadvantages of Glass CO2 Laser

The glass CO2 laser tube, although relatively inexpensive, has high failure rate during use, short lifespan, large size and poor beam mode. These drawbacks not only become increasingly difficult to meet the production processing requirements, but also limit its long-term development.

For example, in terms of lifespan, the designed lifespan of the glass CO2 laser tube is approximately 3,000 hours, and it will affect production due to faults. Moreover, it is also a consumable, and the longer the usage time, the higher the relative cost. With the gradual increase in production requirements, this laser is increasingly unable to meet the needs of industrial production. 

5. Advantages of RF CO2 Laser

The RF CO2 laser is one of the fastest-growing technologies in the industrial laser market in recent years. It is the best alternative to the glass tube CO2 laser.

It adopts a fully metal structure, has a small size, requires no maintenance, has low usage costs, excellent beam mode, high output laser power density, adjustable output power, good power stability, and high reliability. More importantly, the RF CO2 laser has a long lifespan (the design lifespan is generally over 30,000 hours), low maintenance costs, and can be reused after being refill gas without replacing other components. The RF CO2 laser is more suitable for industrial applications with high requirements for continuous stability and precision, especially in high-precision laser processing scenarios. 

In conclusion, the RF CO2 laser outperforms the glass CO2 laser in terms of performance, stability and lifespan, but it also has a higher cost. On the other hand, the glass tube CO2 laser is more suitable for scenarios where performance requirements are not high or budget constraints are present, as it offers a more affordable price.