What is the difference between a CO2 laser and a Fiber Laser?

Laser radiation is mainly a radiation like light but with a special wavelength, this radiation is imperceptible to the human eye because the spectrum visible to humans is very small. Some specific materials only react to certain wavelengths similarly to the human eye only seeing a specific range of the spectrum.

Fiber laser has a wavelength of 1.06 micrometers which is almost the same range of infrared radiation and is near to the visible human spectrum. CO2 lasers have a wavelength of 10.6 micrometers and are far from the human visible spectrum but are still in the infrared range. Depending on the wavelength we can impact a material in different ways.

In comparison, CO2 laser engraves the glass whereas fiber laser passes through it without causing a reaction. Now, if we use a shiny metal the CO2 laser will be reflected without affecting the material, but if we use Fiber laser the metal will react being engraved or cut.

 

Which Laser Cutting Machine is better for my field, Fiber Laser or CO2 Laser Cutting Machines?

Every case is different when we are talking about processing industrial materials, but there is a certain difference in the way machines work with some specific materials based on its thickness. You can base your decision in the advantages that each technology provide, as it is showed in the table below.

  

Some experimental results are showed in order to clarify the difference at the power density at focal point:

 

To understand the comparison between two technologies we need to study the wavelength difference between them. The higher the degree of absorption of the laser, the higher the cutting speed and the cutting quality. The higher absorption of the Fiber wavelength and the higher power density created by the focused beam combine to achieve up to a five-time increase in cutting speeds.

Fiber laser cutting systems can certainly cut up to one-inch thick with higher Fiber laser powers and even cut faster when using nitrogen as the assist gas, but the “sweet spot” where the most significant benefits are showed is in the 5/16 inch and under range for steel when making comparisons with CO2 systems. For certain, if you are processing stainless, aluminum, brass or copper materials, Fiber laser technology is the fastest and most economical regardless of thickness.

The speed benefits using a Fiber Laser Cutting Machine are most profound when nitrogen is employed as an assist gas, because the molten material is expelled from the kerf by the nitrogen just as fast as it is melted. The higher the laser beam power density, the quicker the material is brought to a molten state.