Fiber laser 

A fiber laser creates light in a diode-pumped, rare-earth-doped glass fiber (often ytterbium). The same fiber both amplifies and guides the light to the cutting head. There, the beam is focused to a very small point of high energy density. The result is a narrow cutting gap (kerf), high speed and good detail reproduction-especially in thin to medium-thick sheet metal and in reflective metals such as aluminum and copper. 

Table of contents

Fiber laser vs CO₂ vs plasma vs water 

  • Fiber laser 
    Strengths: Very energy efficient; fast in thin-medium thickness sheet metal; strong on Al/Cu/brass; narrow kerf. 
    Compromises: Edge finish in really coarse material thicknesses may require more fine trim; optics/protective glass require strict cleanliness. 
  • CO₂ laser (our method) 
    Strengths: Robust process window; can provide smooth, "soft" surface in coarse black steel with O₂; well proven in many standard steels. 
    Compromises: Lower power-to-light efficiency than fiber; less advantageous on highly reflective metals. 
  • Plasma 
    Strengths: Cost effective in heavy plate; high throughput. 
    Compromises: Wider kerf, larger HAZ, rougher edge-more finishing at tight tolerances. 
  • Water cutting 
    Strengths: "Cold" process without HAZ; can handle almost all materials/composites and very coarse thicknesses. 
    Compromises: Slower; high cost per meter in metal vs. laser; no heat advantage for plasticizing. 

Materials & thicknesses for fiber lasers 

Which materials work best: 

  • Black steel (S235/S355 and others): Very effective. With O₂ high rate is obtained via the exothermic reaction (oxide edge accepted). With N₂ cleaner edge, often slightly lower speed. 
  • Stainless steel (e.g. 304/316): Usually cut with N₂ for a shiny, low-oxide edge and minimal post-processing. 
  • Aluminum: Requires good beam quality, right focus and N₂ or compressed air; fiber laser handles Al well despite reflection. 
  • Copper/brass: High reflectivity and thermal conductivity, but fiber lasers (1.06 µm) work well with the right parameters and safety glass procedures. 

When fiber laser is the right option 

Process Strength Restriction Edge quality Typical uses 
Fiber laser Metals (also Al/Cu), high efficiency, fast in thin-media Less suitable for organic materials Very good in metal Sheet and tube production, series, tight tolerances 
CO₂ laser Non-metals, plastic/acrylic, wood, thin metal Less effective on reflective metals Very good in plastic/wood Acrylic signs, gaskets, decor, sheet metal 
Plasma Rough sheet, lower cost per meter Wide notch, larger HAZ Coarse goods Thick steel, rough cutting 
Water jet All materials, no HAZ Slower, abrasive handling Very good Thick composites, heat sensitive 

Contact us for more information

Are you planning laser cut details? At Thor Ahlgren, we deliver CO₂ laser cutting with high and consistent quality in metal. We do not use fiber lasers, but are happy to share our experience so you choose the right method for edge, tolerance and lead time requirements.

Please send prototype files