Comparison

CO2 vs Fiber Laser: Which One Should You Buy?

Updated 2026-10-12 · 4 min read

CO2 and fiber lasers look similar on a specification sheet — both have a power rating, a working area and a cutting head. In use they are completely different tools. The wavelength difference decides which materials each can cut, and that single fact should drive the decision more than price or power.

The difference that decides everything: wavelength

A CO2 laser produces light at 10.6 µm in the infrared. A fiber laser produces light at about 1.07 µm. Materials absorb these wavelengths very differently.

This is not a tuning issue. A CO2 laser physically cannot cut 6 mm aluminium efficiently because most of the beam energy is reflected rather than absorbed. A fiber laser passes through acrylic instead of cutting it because the material is transparent at that wavelength.

Side-by-side comparison

Where fiber wins

Thin metal, high volume. Fiber lasers cut thin sheet dramatically faster than CO2 at the same power, and the gap widens as you go thinner. For a shop cutting 1–3 mm steel or stainless all day, this is the whole argument.

Reflective metals. Aluminium, brass and copper are routine on fiber and difficult on CO2. If any part of your work involves these, CO2 is the wrong choice.

Running cost. Roughly a third of the electricity per delivered watt, no laser gas, and no mirror train to realign. Over a year of production the difference is substantial — often enough to change the payback calculation.

Thicker metal than the equivalent CO2. A 3 kW fiber source will cut carbon steel far thicker than a 3 kW CO2 tube, because more of the energy reaches the cut.

Where CO2 wins

Non-metal cutting. Acrylic is the clearest case. A CO2 laser leaves a flame-polished edge; fiber melts and clouds it. Wood, leather, fabric and paper behave the same way — CO2 cuts them, fiber marks or chars them.

Mixed metal and non-metal work. Signage shops, model makers and prototype workshops routinely cut acrylic, plywood and thin steel on the same machine. A CO2 machine with a follow-up cutting head handles that mix; a fiber machine does not.

Lower entry cost on small beds. A small CO2 cutter is cheaper than a comparable fiber machine, which matters for low-volume or craft work.

Glass and some plastics. Fiber simply does not work on these; CO2 does.

Cost of ownership, honestly

Purchase price is the smaller number over the life of a machine. The costs that matter:

1. Electricity per delivered watt. Fiber is roughly three times more efficient, so the same cutting job draws far less power.
2. Laser source replacement. CO2 tubes are cheaper individually but have a short life and are replaced repeatedly. Fiber sources cost more to replace but last far longer.
3. Optics. A CO2 machine's mirror path needs periodic alignment and mirror replacement. A fiber machine delivers the beam through a cable, so there is little to align — the cutting head lens is the main consumable.
4. Assist gas. Both need it; oxygen for carbon steel, nitrogen for stainless. Fiber cuts faster, so gas per part is usually lower.
5. Chiller load. The lower efficiency of CO2 means more waste heat to remove, so the chiller runs harder.

A decision rule that works

• Cutting metal only → fiber laser. Choose power by the thickest material you actually cut, not by the thickest you might.
• Cutting non-metal only → CO2 laser. Choose bed size first, then power.
• Cutting mostly non-metal with some thin metal → CO2, and accept the metal limitation.
• Cutting mostly metal with some non-metal → fiber for the metal, and send the non-metal work out or add a small CO2 machine later.
• Growth path → many fabricators start with CO2 for mixed work and add a fiber machine when metal volume justifies it, rather than replacing the CO2.

That last point is worth stressing: the two machines are complements, not substitutes. Shops that do both kinds of work usually end up with both, because neither machine can do the other's job well.