Laser Wavelengths Explained: What Works Best for Each Material

Introduction

When you're building or buying a laser system, one of the most important — and often misunderstood — factors is wavelength. It’s not just a number on a spec sheet. Wavelength determines how your laser interacts with different materials, how efficiently it cuts or welds, and whether it’s even usable for your application at all.

In this guide, we’ll break down what laser wavelength actually is, how it affects material interaction, and how to choose the right wavelength for your process.

What Is Laser Wavelength?

Wavelength refers to the distance between peaks in a light wave — typically measured in nanometers (nm) or micrometers (µm). Lasers emit light at specific wavelengths, and that wavelength controls how the beam behaves: how far it penetrates, how tightly it can be focused, and — most importantly — how well it’s absorbed by different materials.

Shorter wavelengths (like UV or green lasers) generally offer better surface absorption and precision. Longer wavelengths (like CO₂ lasers) tend to penetrate deeper but are limited by how reflective the material is.

Why Wavelength Affects Absorption

Not all materials react the same way to light. Some absorb certain wavelengths easily and convert that energy into heat (ideal for welding or cutting). Others reflect the light or let it pass through — which means no heating, no melting, and no laser processing.

Here’s why that happens:

• Metals typically reflect long wavelengths (like 10.6 μm from a CO₂ laser), but absorb shorter near-infrared wavelengths like 1.064 μm from fiber or Nd:YAG lasers much more effectively.

• Plastics, wood, glass, and organic materials tend to absorb longer infrared wavelengths better, making CO₂ lasers a great fit.

• Highly reflective metals like copper and gold can reflect most of the energy from standard fiber lasers. That’s where green lasers (532 nm) come in — shorter wavelengths improve absorption and make micromachining or fine welding possible.

The level of absorption depends on the material’s electron structure, refractive index, and even surface finish. This is why the same laser may work beautifully on one material and fail completely on another.

What the Wavelength Chart Actually Shows

The so-called “laser wavelength chart” isn’t a graph or scientific spectrum — it’s a reference table that shows which lasers (by wavelength) work best with which materials.

In simple terms:

• It connects laser types and wavelengths to common materials and applications.

• It helps engineers or buyers figure out which laser technology is most compatible with the job at hand.

Below is our version of this chart — built to give you a clearer picture of how each laser performs in real-world scenarios.

Laser Wavelengths by Material and Application

So… Which Wavelength Should You Use?

It depends on what you’re cutting, welding, marking, or engraving.

• Need to cut stainless steel? Go with a fiber laser at 1064 nm.

• Mark a polymer with no charring? Use a UV laser at 355 nm.

• Microweld copper contacts? Green lasers at 532 nm are your best bet.

• Cut acrylic or wood cleanly? Stick with a CO₂ laser.

The key is matching the wavelength to the material’s absorption sweet spot. If you don’t, you’ll either get poor results or no interaction at all.

Final Thoughts

Laser wavelength is more than just a number — it’s one of the most important factors in choosing or designing a laser system. It affects performance, compatibility, and cost. Whether you're working with metal, plastic, or something more exotic, understanding how wavelength influences absorption and process efficiency helps you make better decisions (and avoid expensive mistakes).

If you're not sure which wavelength is right for your application, we’re here to help.