Myth Buster: Fiber Vs CO2 Lasers

What’s the ultimate laser for your application – should I choose Fiber laser, also known as Solid State Laser (SSL), or a CO2 laser?

Answer: It depends on the type and thickness of the material you are cutting.

Why?: Due to the rate at which the material absorbs the laser. You need to choose the right laser for your application.

The absorption rate is influenced by the wavelength of the laser and also the angle of incidence.

Different types of lasers have different wavelengths, for example the fibre (SSL) laser’s wavelength is far smaller at 1 micron (on the right) than the CO2 lasers wavelength at 10 micron, shown on the left:

The angle of incidence means, the distance between point at which the laser beam hits the material (or surface), perpendicular (at 90) to the surface, so where it makes a T shape.

The angle of incidence increases (shown as a1 and a2 below) as the material increases in thickness. You can see below that with the thicker material, the orange line is at a greater angle than the blue line on the diagram below.

Which laser type for which application?

Fiber Laser/SSL

Highlights

• Speed – Faster than CO2 lasers in thin materials as the laser can be absorbed quickly with a slight lead in speed when cutting with Nitrogen (fusion cutting).
• Cost per part – less than the CO2  laser depending on sheet thickness.
• Safety – Strict safety precautions must be taken (machine is completely enclosed) as the laser light (1µm) can pass through very narrow openings in the machine’s frame causing irreparable damage to the eye’s retina.
• Beam guidance – fiber optics.

CO2 Laser

Highlights

• Quality – Quality is consistent throughout all thicknesses of material.
• Flexibility – high, suitable for all material thicknesses.
• Safety – CO2 laser light (10µm) is better absorbed by the machine frame, which lowers the risk of irreparable damage to the retina. Personnel should not look directly at the cutting process through the acrylic pane in the door as the bright plasma also presents a risk to sight over a period of time. (Similar to looking at the sun.)
• Beam guidance – mirror optics.
• Cutting with Oxygen (flame cutting) – there is no difference in quality or speed shown between the two types of lasers.

  

  References:

  TRUMPF Presentation: Solid-state lasers in the TruLaser area – Technical considerations – Fiber Laser

  TRUMPF Presentation: Solid-state lasers in the TruLaser area – Technical considerations