Choosing a laser cutter is one of the biggest equipment decisions a fabrication shop makes. Two technologies cover nearly all the work: CO₂ and fiber. Both are called laser cutters, but they are different machines built for different materials. This article explains which one suits which job.
How a CO₂ laser works
A CO₂ laser makes its beam from a gas mixture, mostly carbon dioxide, and produces infrared light at about 10.6 micrometers. Organic and nonmetal materials absorb that wavelength well.
CO₂ lasers cut acrylic, wood, MDF, plastics that contain no PVC, foam, rubber, leather, fabric, paper and cardboard. On acrylic, the edge usually comes out smooth and polished and needs little or no finishing. Never cut PVC with a laser: it gives off corrosive and toxic fumes.
How a fiber laser works
A fiber laser generates its light inside an optical fiber doped with a rare-earth element such as ytterbium. The wavelength is about 1.06 micrometers, which metals absorb readily, so it cuts metal quickly and precisely.
Fiber lasers cut stainless steel, carbon steel, galvanized steel, aluminum, brass and copper. In many shops they have replaced plasma, and waterjet on thin material, for sheet metal cutting.
Which laser for which material
| Material | CO₂ laser | Fiber laser |
|---|---|---|
| Acrylic | Excellent | Not suitable |
| Wood and MDF | Excellent | Not suitable |
| Plastics (no PVC) | Excellent | Limited |
| Leather and fabric | Excellent | Not suitable |
| Stainless steel | Not the right tool | Excellent |
| Carbon steel | Not the right tool | Excellent |
| Aluminum | Poor | Excellent |
| Brass and copper | Poor | Excellent |
Edge quality
CO₂ on acrylic. Smooth, flame-polished edges with good clarity and little finishing. That matters where the edge is visible, such as on displays and lit panels.
Fiber on metal. Square edges with little burr and tight dimensional accuracy, which is what parts need when they will be welded and fit-up counts.
Speed
On acrylic and wood, CO₂ is faster. On metal, fiber is faster. Because each is tuned to different materials, they rarely compete head to head.
Typical jobs
CO₂:
- Acrylic panels, letters and displays
- Light diffusers
- Wood and MDF parts
- Leather and fabric goods
- Stencils and templates
- Packaging and prototypes
Fiber:
- Sheet metal parts and enclosures
- Brackets and mounting hardware
- Stainless steel panels and logos
- Aluminum housings and cabinets
- Precision parts for welded assemblies
Running costs and maintenance
A CO₂ laser needs its tube replaced as it wears, its mirrors and lens cleaned, its beam aligned and its cooling checked. It also uses more electricity than a fiber laser of similar output.
A fiber laser needs much less optical care, because there are no mirrors in the beam path from the source. Routine work is cleaning or replacing the protective lens, replacing nozzles, looking after the chiller and checking the assist gas.
Why many shops run both
A shop that cuts both acrylic and metal often installs both technologies, because each does its own jobs best. A typical flow: design the job, cut the nonmetal parts on the CO₂ laser, cut the metal parts on the fiber laser, then join the metal with a handheld fiber laser welder and assemble.
Ascent options
- CO₂ only: the 130W CO₂ laser cutter and engraver, and the 4 ft x 8 ft CO₂ laser cutter at 80 to 280W.
- Fiber only: the fiber laser cutter at 3000W or 4000W.
- Both on one bed: the combination cutter, with a 150W CO₂ laser and a 2000W fiber laser.
- Both at the same time: the dual gantry cutter, with a 500W CO₂ gantry and a 3000W or 6000W fiber gantry that cut independently.
All of them are Class 4 lasers, so plan for enclosure, fume extraction and laser eyewear. See our laser safety page.
The bottom line
The question is not which laser is better. It is which one fits the material on your table. For acrylic, wood and other nonmetals, choose CO₂. For metal, choose fiber. If you cut both, consider a machine with both lasers. Installation and operator training at your facility are included in the price of every Ascent cutter. Contact us to work out the configuration that fits your work.
