2. Wavelength and Material Absorption: The Physics That Matters
Shenzhen, China
Published: Jul 3, 2026
2. Wavelength and Material Absorption: The Physics That Matters
Understanding why different materials respond to different lasers comes down to one principle: a material can only be marked by a wavelength it absorbs.
| Wavelength | Best Absorbed By | Poorly Absorbed By |
|---|---|---|
| 1064nm (Fiber) | Metals (Fe, Al, Cu, Ti, Au), some dark plastics | Transparent plastics, glass, wood, leather, white polymers |
| 10.6μm (CO2) | Wood, paper, leather, glass, acrylic, rubber, some plastics | Bare metals, transparent polycarbonate, silicone |
| 355nm (UV) | Plastics (white, transparent, colored), glass, silicone, flexible PCBs | Thick metals (low power limits depth) |
This absorption pattern is why wavelength — not power — is the primary selection criterion. A 100W CO2 laser still can’t effectively mark bare stainless steel, because 95%+ of the energy reflects off the surface.
