Laser Cutting Master Class Series:
- Part 1: Diode "Blue" Lasers (You are here)
- Part 2: CO2 Lasers & The Acrylic King (Coming Soon)
- Part 3: Fiber Lasers for Metal (Coming Soon)
Five years ago, owning a laser cutter meant buying a massive, water-cooled industrial machine. Then, the "Blue Laser" revolution happened.
Today, you can buy a machine on Amazon for $400 that fits on your desk and cuts wood. But the marketing around these machines is full of traps. Manufacturers lie about power, and physics dictates what they can and cannot cut.
In Part 1 of our series, we strip away the marketing hype to tell you exactly what a Diode Laser is good for.
What is a Diode Laser?
Unlike old-school tubes, these use a solid-state semiconductor—basically a super-powered LED. They emit light at a 450nm Wavelength, which appears visible Blue/Violet to the human eye.
The "Blue" Problem:
Because the light is blue, it interacts with materials differently than other lasers.
- It cuts: Wood, Leather, Black Acrylic, Paper, Cardboard.
- It ignores: Clear Acrylic, Transparent Glass. (The blue light passes right through like a window).
The "Wattage Lie"
If you take one thing from this article, let it be this: Ignore the "Input Power."
You will see cheap lasers on Amazon advertised as "40W Laser!" or "90W Machine!". This is usually the electricity the machine pulls from the wall, not the laser power.
| Class |
Optical Output (Real Power) |
What it can actually do |
| Entry Level |
5W - 10W |
Engraving wood. Cutting thin cardboard. Struggle to cut 3mm plywood. |
| Mid-Range |
20W |
The sweet spot. Cuts 5mm plywood in one pass. Engraves stainless steel (slowly). |
| High-End |
40W (Quad Diode) |
Cuts 10mm wood. Fast engraving. Expensive. |
Pros & Cons of Diode Lasers
The Good
- Durability: Diodes last 20,000+ hours. They are solid state and rugged.
- Resolution: The beam spot is tiny (0.08mm), allowing for photo-realistic engraving.
- No Alignment: Unlike CO2 lasers, there are no mirrors to align. It works out of the box.
The Bad
- Safety: Most are "Open Frame." If you look at the blue dot, you go blind. Period.
- Speed: Much slower than CO2 lasers.
- Material Limits: Cannot cut Clear Acrylic (it just melts/cracks) or white materials easily.
Safety: The "Widow Maker" Factor
We need to be serious for a moment. Most Diode lasers are sold as "Open Frame" gantries. There is no box around the laser.
EYE SAFETY IS MANDATORY
The reflected blue light from a 10W diode can instantly cause permanent retinal damage.
- Never run the laser without an enclosure.
- Never trust the free green glasses that come in the box. Buy certified OD6+ rated eyewear.
- Keep pets and children out of the room. A dog looks at the bright light instinctively.
The 2025 Recommendations
If you want to get into the hobby, here is the current landscape:
- The Premium Pick: xTool D1 Pro / S1. Expensive, but they have great software (XCS) and safety enclosures are available.
- The Budget Pick: Creality Falcon or Sculpfun. Great hardware for the price, but you strictly need to use LightBurn software (do not use the free LaserGRBL, it is too limited).
Conclusion: Is a Blue Laser Right for You?
If you primarily want to engrave logos on wood, make leather patches, or cut thin plywood for model airplanes, a 20W Diode Laser is an amazing tool. It is low maintenance and precise.
However, if you want to make clear acrylic signs, cut thick boxes, or run a production business, you need to graduate to the big leagues. Stay tuned for Part 2: The CO2 Laser.
Show off your engravings!
Did you burn a custom coaster or a leather wallet? Post your results in the CNC & Fabrication forum. We love seeing LightBurn power settings and speed tips!
Join the Maker Community ?