Diode vs CO2 vs Fiber Laser: Which Type Fits What You Sell?

“Which laser should I buy?” is really “which wavelength do my materials absorb?” A diode, a CO2 and a fiber laser can all be 40 W on paper and still do completely different jobs. This guide explains why, then gives you a decision table you can use in two minutes.

The one-minute physics

A laser only affects a material that absorbs its light. Absorbed light turns into heat; heat burns, melts, vaporizes or discolors the surface. Light that is reflected or passes through does nothing useful, and can damage something else.

Each laser type emits one wavelength:

Epilog lists its CO2 sources at 10.6 microns and its fiber sources at 1,064 nm. Creality lists the Falcon2 40W diode at 455 ± 5 nm.

Materials absorb these wavelengths very differently:

• Organic materials and most plastics (wood, leather, paper, acrylic, glass, stone) absorb the long CO2 wavelength very well. KEYENCE describes the CO2 advantage as a “longer wavelength” that allows “excellent absorption into organic materials like wood and plastic.” That includes clear acrylic and glass, which look transparent to your eye but are opaque at 10.6 µm.
• Metals reflect most CO2 light but absorb 1,064 nm much better. That is why fiber lasers are the metal specialists.
• Blue light is absorbed by dark, opaque organics, but passes through clear materials and reflects off white, blue and shiny surfaces. xTool’s own guide says diode light “passes through the clear acrylic, leaving it intact.”

Hold on to that and everything else follows.

What each type does best

Diode lasers: the affordable generalist for wood

Best at: engraving and cutting wood and plywood, leather, felt, cork, paper and dark acrylic; stripping powder coat, paint and anodizing from metal; engraving slate.

Weak at: clear, white or blue acrylic (cannot cut), glass, bare metal (marks only, with spray), speed on thick stock.

Why people choose it: low price, no glass tube, no water chiller, small footprint, and many enclosed models are Class 1. Modern 20 to 40 W diodes cut surprisingly thick wood. xTool rates the S1 40W at 18 mm of cherry in one pass, and Creality’s Falcon2 40W page claims 20 mm of wood in one pass (another line on the same page says 20 mm of cork). Those are manufacturer best cases, not our measurements.

Full details: What Can a Diode Laser Cut?

CO2 lasers: the production workhorse for organics

Best at: fast cutting of wood, plywood and any color of acrylic, including clear; frosty-white acrylic engraving; glass etching; leather, fabric, paper, rubber stamps; removing powder coat.

Weak at: bare metal (needs a marking spray), size and weight, maintenance.

Why people choose it: CO2 is the standard for sign makers, wedding and event decor, and anyone selling acrylic. xTool rates the 55 W P2S at 20 mm acrylic and 18 mm wood, and lists “can cut clear acrylic” as yes, which no diode can claim.

Trade-offs to plan for: glass CO2 tubes are consumables. OMTech lists an estimated 11,000-hour life for the Polar Lite 55W’s tube. Desktop CO2 machines are heavy (xTool lists the P2S at 45 kg, OMTech the Polar Lite at 41 kg) and need an exhaust route.

Fiber lasers: the metal specialist

Best at: marking and deep-engraving bare stainless steel, aluminum, brass, silver, gold and titanium; industrial-grade plastics; MOPA fiber sources can also produce color marks on stainless and titanium.

Weak at: wood (faint or scorched marks), clear acrylic, cutting anything thicker than thin metal, and work area (most are galvo machines with a small field).

Why people choose it: jewelry, knives, tags, tools, firearms accessories and anything where the mark must survive abrasion. OMTech notes that only fiber lasers achieve genuine deep carving for “badges, stamps, or designs intended to be paint-filled.” Diodes and CO2s can only mark bare metal with help.

Most small-business fiber machines are galvo systems, which steer the beam with mirrors instead of moving a head. That is a separate choice with its own trade-offs; see Galvo vs Gantry.

The dual-source middle ground

Several newer machines combine two wavelengths. xTool’s F1 Ultra pairs a 20 W fiber with a 20 W diode; the F2 Ultra pairs a 60 W MOPA fiber with a 40 W diode. They cover metal and wood in one box, but inside a small galvo field (220 × 220 mm, per xTool). They are marking and engraving machines first, not sheet cutters.

Side-by-side

Material verdicts come from Epilog’s CO2/fiber compatibility list, xTool’s acrylic guide, and our own Can I Laser This? dataset.

Price bands (manufacturer list prices, September 2026)

These are ranges drawn from the machines we have researched so far, not market averages.

Budget beyond the machine: fume extraction, air assist (if not built in), a rotary for drinkware, safety glasses for Class 4 machines, and materials. Our Startup Cost Calculator adds these up, and the Laser ROI Simulator shows payback with your own prices.

Decision table: start from what you sell

Still unsure? The Machine Matchmaker asks about products, space and budget and returns a machine type. Then line up researched machines in the Compare tool.

Common mistakes

1. Comparing watts across types. A 40 W diode and a 40 W CO2 are not the same tool. Compare what each is rated to cut in the material you use.
2. Buying a diode for acrylic. Clear acrylic needs CO2; no diode wattage changes that.
3. Buying a fiber for wood. Fiber galvos are fantastic on metal and frustrating on wood unless they carry a diode too.
4. Forgetting the workspace. Desktop CO2 machines like the P2S (45 kg) and Polar Lite (41 kg) are heavy and need a window or duct. Measure before you buy.
5. Ignoring software. xTool machines run xTool Studio; many others use LightBurn. Software affects your workflow every day. See xTool vs Creality Falcon for an example.