What Type of Barrier or Curtain Do I Need for a CO₂ Laser?

CO₂ lasers are used for cutting, engraving, marking, processing, and many other industrial applications. When hazardous laser radiation could extend beyond the intended work area, an appropriate laser safety barrier, curtain, or enclosure may be needed to help establish and contain the laser controlled area.

But there is no single barrier that is automatically required simply because a laser is a CO₂ laser.

The selection starts with understanding the laser wavelength, application, and the potential laser exposure that could actually reach the containment boundary.

Many CO₂ lasers operate at approximately:

10,600 nm (10.6 µm)

However, not all CO₂ lasers operate at exactly 10,600 nm. CO₂ systems can operate at other wavelengths, including approximately 9.3 µm and 9.6 µm.

This matters because laser safety barrier materials can interact differently with different wavelengths.

A barrier tested or evaluated for a 1064 nm fiber laser, for example, should not automatically be assumed to provide the same performance at 10,600 nm.

Before selecting a barrier, verify the actual operating wavelength of the laser and make sure the barrier is appropriate for that wavelength.

A common question is:

“I have a 100 W CO₂ laser. What barrier do I need?”

Or:

“My CO₂ laser is 1,000 W. What irradiance rating should my curtain have?”

The laser's output power is important, but wattage alone does not tell you the irradiance that will reach the barrier.

Barrier selection can depend on factors such as:

Two systems using the same laser power can therefore create very different exposure conditions at their containment boundaries. F

This is one of the most important practical questions.

A barrier positioned close to a potential beam path can experience a very different exposure than a barrier located farther from the process and primarily exposed to scattered or diffuse laser radiation. For how energy spreads, see this video:

As laser radiation spreads over a larger area, its irradiance can decrease substantially.

This is why determining the potential exposure at the barrier is generally more useful than simply comparing the laser's rated wattage with a barrier's published irradiance rating. For more see video below:

Laser safety barriers and curtains should not to be treated as beam dumps intended to withstand an indefinitely sustained, focused direct beam.

Even materials with high published irradiance ratings have finite damage thresholds.

A laser safety system should therefore consider:

The objective is to establish an appropriate containment system for the actual laser application—not simply to find the material with the highest number on its specification sheet.

Both can be appropriate depending on the application. See the video:

Softwall curtains can be useful when the application requires:

They can be particularly useful for creating controlled areas around changing or temporary laser processes.

Hardwall systems may be preferred when the application requires:

The appropriate choice is not simply “hardwall is safer than softwall.” The barrier needs to be appropriate for the wavelength and reasonably foreseeable exposure conditions of the application.

Barrier performance should be considered at the wavelength where the barrier will actually be used.

This is especially relevant when comparing CO₂ lasers with common fiber lasers.

A barrier's performance at approximately 1064 nm does not necessarily establish identical performance at 10,600 nm.

Laser Safety Industries has therefore tested its Hardwall and softwall Laser Safety Barriers at multiple wavelength regions rather than assuming that performance at one wavelength applies universally.

For CO₂ laser applications, our hardwall barrier material has been tested at approximately 10,600 nm.

Laser Safety Industries Hardwall Laser Safety Barriers have been tested at:

4,000 W/cm² @ 10,600 nm

This testing provides useful wavelength-specific performance information for evaluating the barrier for CO₂ laser applications.

However, a 4,000 W/cm² test result does not mean that every CO₂ laser requires a 4,000 W/cm² barrier, nor does it mean the barrier should be used as a beam dump for an indefinitely sustained direct strike.

The appropriate barrier should still be selected based on the reasonably foreseeable worst-case exposure conditions at the barrier.

If a flexible curtain is preferred, the same basic selection principles apply.

The curtain material should be evaluated for:

Actual wavelength + potential exposure at the curtain + exposure duration + application

Do not assume that a curtain appropriate for another laser wavelength automatically provides equivalent performance for a CO₂ laser.

If there is uncertainty about a material's performance at the particular CO₂ wavelength or exposure condition, consult the manufacturer and your Laser Safety Officer before relying on it as the containment boundary.

Not necessarily.

If a CO₂ laser is contained within a properly designed enclosed system, additional room-scale curtains or barriers may not be required simply because the internal laser is high powered.

For example, a complete enclosed laser system may be classified as Class 1 because hazardous laser radiation is not accessible during normal operation.

The containment requirements can change during servicing, alignment, modification, removal of protective housings, or other conditions that make hazardous laser radiation accessible.

This is why the actual system and how it is being used matter.

Before selecting a containment system, identify:

Your LSO or other qualified laser safety professional can use this information as part of the hazard evaluation.

There is no universal “CO₂ laser barrier” that should be selected solely from the laser's wattage.