Alternate
Wavelengths for
CO2 Lasers
Why Laser Wavelength Matters
Every material has a characteristic absorption spectrum—that is, there are certain
wavelengths of light that a given material absorbs more readily than others. Why does
this matter? Lasers produce light at very specific wavelengths. By pairing that wavelength
to a material that easily absorbs it, the application results are of higher quality and theprocessing itself is faster.

Laser Types
One of the defining characteristics of different laser types (including CO2, Fiber, YAG, UV, and many others) istheir wavelength.

CO2 lasers have long wavelengths, around 9.3 – 10.6 µm, with 10.6 µm as the most common. Thesewavelengths pair nicely with the absorption spectrum from polymers, ceramics, textiles, natural materials
like paper or wood, and certain metals. By contrast, the shorter wavelength YAG or Fiber lasers tend tohave better absorption in metals.

CO2 Laser Wavelengths
Once the type of laser has been chosen, there are options to optimize the wavelength for a specificmaterial. CO2 lasers are typically available in three wavelengths: 9.3 µm, 10.2 µm, and 10.6 µm.
10.6 µm• This wavelength works well for most common marking, engraving, and cutting
applications. The exceptions are noted below.

10.2 µm• Polypropylene Films (OPP, CPP, PP), commonly found in labels and packaging, canachieve 2.5 – 4X speed increases when cutting or perforating at this wavelength.
• Glossy Paperboard Packaging can be marked with higher contrast at this wavelength,
since the package includes a polypropylene surface layer.

9.3 µm• PET Plastic comes in many forms. It is commonly used as rigid packaging (wateror beverage bottles especially) and PET films are found in both packaging and aselectronics screen protectors. When marked, this wavelength produces a high-contrast
frosted appearance, perfect for permanent date codes or batch marking. When cut, thiswavelength delivers minimal melting or heat affected zone (HAZ) along the cut edge forhigher quality results.
• Polarizer Films for LCD Displays can be cleanly cut with minimal melting or HAZ usinga high peak power version of this wavelength.
• Polyimide (Kapton) Films are commonly used in electronics. A high peak power
version of this wavelength reduces the charring characteristic of this material, producing
better results when cutting, drilling, or ablating.

©2021 Novanta Corporation. All rights reserved.

Alternate Wavelengths for CO2 Lasers

9.3 µm(cont.)• FR4/FR2 PCBs all tend to char when laser cut or drilled. A high peak power version ofthis wavelength significantly reduces the effect for higher quality results.
• Polycarbonate is used across a variety of industries for its durability. A high peak power
version of this wavelength significantly reduces the charring and discoloration commonly
associated with laser processing this material.
• Pebax Plastic is often found in medical tubing. This wavelength produces better
vaporization with less melting when cutting or ablating Pebax.

Note that while the 10.2 and 9.3 µm wavelengths excel in processing certain materials, they are also
capable of processing more common materials as well. If you plan to process a variety of materials, anApplications Engineer can help select the optimal wavelength for your needs.

Application Example: Polypropylene (PP)This is the absorption spectrum for polypropylene, with peaks indicating wavelengths with higherabsorption. The two red lines represent 9.3 and 10.6 µm respectively. The green line, corresponding to anice absorption peak, is 10.2 µm. Based on this, we expect 10.2 µm to perform better than the other CO2
wavelengths in marking and cutting applications.

Marking Glossy Paperboard
10.6 µm: While legible, the mark is inconsistent.

10.2 µm: Clean, consistent, and highly visible mark.

©2021 Novanta Corporation. All rights reserved.

Alternate Wavelengths for CO2 Lasers

Cutting OPP/BOPP Films
10.6 µm: Cutting produces a noticeable melt lip.

10.2 µm: Cutting is 2.5X faster, and produces a crisp
edge with minimal melt lip.

Application Example: Polyethylene Terephthalate (PET)In this absorption spectrum for PET, the two red lines represent 10.2 µm and 10.6 µm respectively. The green
line representing 9.3 µm is positioned at an absorption peak, so we would again expect better processing atthat wavelength.

Marking PET Bottles10.6 µm: While legible, the mark is nearly invisible.
There is also a danger of puncturing the material due
to higher transmission.

9.3 µm: The mark has a frosted white appearance
for better visibility. 9.3 µm also interacts at thesurface of the material, minimizing risk of puncture.

©2021 Novanta Corporation. All rights reserved.

Alternate Wavelengths for CO2 Lasers

Cutting PET Films
10.6 µm: Cutting produces a large amount of debris
and more melting at the cut edge.

9.3 µm: Cutting produces a clean edge with no residue
and minimal melting.

Conclusion
By selecting the proper laser wavelength for the material, application results are of higher quality and can typicallybe processed at higher speeds. Optimizing the absorption of the laser energy is especially critical for sensitive
materials, like thin films, or processes with high tolerances, like selective cutting of labels.
To determine the best option for your application, contact us to schedule an application test.

Contact Us
Americas & Asia PacificNovanta Headquarters
Bedford, USA
P +1-781-266-5700
Photonics@Novanta.com

Europe, Middle East,Africa
Novanta Europe GmbH
Wackersdorf, Germany
P +49-9431-7984-0
Milan, Italy
P +39-039-793-710

China

JapanNovanta Sales & Service Center Novanta Service & Sales Office
Tokyo, Japan
Shenzhen, China
P +81-3-5753-2460
P +86-755-8280-538
Suzhou, China
P +86-512-6283-7080
Photonics.China@Novanta.com

Photonics@Novanta.com©2021 Novanta Corporation. All rights reserved.

Photonics.Japan@Novanta.
com