A laser cutter focuses a high-energy beam into a tiny spot that melts, burns, or vaporizes material along a computer-guided path.
For the full breakdown, see our best At Home Laser Cutter guide.
The beam that slices through steel is invisible, and nothing about the cut looks like sawing. Understanding how a laser cutter works comes down to one sequence: a beam is generated, focused to a tiny spot, and steered along a programmed path while the material underneath melts, burns, or vaporizes away. That sequence explains what a machine can cut, why the settings matter, and what can go wrong.
How Does The Beam Actually Cut?
The beam cuts by concentrating so much energy on one spot that the material there melts, burns, or vaporizes. Assist gas then blows the molten debris out of the kerf, and the machine steers the beam, or moves the workpiece, so the focused spot traces the full shape from the design file. Every other component exists to make that transfer of energy precise and safe.
Inside the machine, five steps happen in sequence:
- Beam generation. The laser source produces the beam, usually a CO2 gas tube or a fiber laser.
- Beam delivery. Mirrors or an optical fiber route the beam from the source to the cutting head.
- Focusing. A lens squeezes the beam to a tiny point, concentrating the heat where the cut belongs.
- Material removal. That concentrated heat melts, burns, or vaporizes the material, forming the kerf, the width of the cut.
- Assist gas. Compressed air, oxygen, or nitrogen blows molten material and smoke out of the kerf for a cleaner edge.
The assist gas also keeps smoke and splash-back off the lens, protecting the optics as it clears the cut.
How A Vector File Becomes A Laser Cut
Nothing gets cut until a design exists. The working file is a vector drawing; SVG and DXF are the most common formats, and the controller converts those paths into motion commands. Vector cutting traces the outlines, while raster engraving scans line by line like a printer, varying power to create shades.
The laser source decides what the beam can handle. CO2 lasers cut and engrave non-metals, including wood, acrylic, leather, paper, and glass. Fiber lasers cut and mark metals,