Why Do Lasers Operate at Slightly Different Wavelengths?

Yes. These wavelengths are relatively close together and all fall within the near-infrared (near-IR) portion of the electromagnetic spectrum.

However, the fact that wavelengths are close together should not, by itself, be used to assume identical protective performance.

How wavelength coverage is established also depends on the type of protective product and its testing or specifications.

For laser safety eyewear and viewing windows, compare the actual laser wavelength directly with the manufacturer's published optical density (OD) wavelength range.

For laser safety barriers, consider the wavelengths and conditions under which the barrier was tested, along with the manufacturer's recommendations for the intended application.

Always verify the actual operating wavelength of the laser rather than assuming that 1064 nm, 1070 nm, and 1080 nm are interchangeable specifications.

Radiation at 1064 nm, 1070 nm, and 1080 nm is outside the visible range of the human eye.

You cannot rely on seeing the operating beam to determine:

Some industrial laser systems use a separate visible aiming or guide beam to help indicate the intended location of the invisible operating beam.

However, the aiming beam and operating beam are different beams and may operate at very different wavelengths.

For more information, see Operating Beam vs. Aiming Beam: What's the Difference?

Yes.

Laser safety eyewear is specified according to the optical density it provides over particular wavelength ranges.

Suppose a pair of laser safety glasses is specified:

OD 6+ @ 1064 nm

That specification establishes the stated attenuation at 1064 nm.

It does not, by itself, establish OD 6+ protection at:

The filter may provide protection at those wavelengths, but you need to verify that from its complete published specifications.

For example, eyewear specified as:

OD 6+ @ 1030–1100 nm

would include 1064 nm, 1070 nm, and 1080 nm within that stated wavelength range.

The required OD must still be appropriate for the particular application.

For more information, see What Laser Safety Glasses Do I Need for a 1060–1080 nm Laser? For more information, on reading optical density notation see OD Laser Safety Guide or this video:

The same principle applies to laser safety viewing windows.

A window's protection is specified across particular wavelength ranges.

If your laser operates at 1080 nm, do not assume a window whose published protection ends at 1070 nm provides appropriate protection simply because the wavelengths are close together.

The operating wavelength should fall within the window's published protection range, and the window should provide sufficient OD at that wavelength for the reasonably foreseeable worst-case exposure conditions at the window.

For more information, see What Laser Safety Window Do I Need for a 1060–1080 nm Fiber Laser?

Wavelength is also relevant when evaluating laser safety barriers because laser-material interactions can vary with wavelength.

However, barrier specifications and recommendations should be understood in the context of the actual wavelengths and conditions under which the material was tested.

For example, Laser Safety Industries performs barrier irradiance testing at 1064 nm for barriers intended for common near-infrared fiber laser applications.

1064 nm is within the same near-infrared region as many industrial fiber lasers operating around 1070 nm and other nearby wavelengths. Based on the barrier material, available testing, application, and expected exposure, Laser Safety Industries may recommend these barriers for appropriate applications within the broader 1060–1080 nm range.

However, this should not be interpreted to mean that the barrier has been independently irradiance-tested at every individual wavelength between 1060 and 1080 nm.

The specific test wavelength and test conditions should always be distinguished from the broader range of applications for which a barrier may be recommended.

For more information, see What Type of Barrier or Curtain Do I Need for a 1060–1080 nm Fiber Laser?

Some lasers may be specified with a wavelength range rather than one exact wavelength.

For example, a manufacturer might specify an operating range that spans several nanometers.

In that case, laser safety equipment should be evaluated against the wavelength range requiring protection, rather than arbitrarily selecting one wavelength in the middle.

For eyewear and viewing windows, verify that the required OD is provided across the relevant wavelength range.

For example, if your requirement is:

OD 6+ @ 1060–1080 nm

then a filter whose published specification provides OD 6+ throughout 1060–1080 nm can be compared directly against that requirement.

Protection specified only at 1064 nm would not, by itself, establish OD 6+ throughout the entire 1060–1080 nm range.

For selecting laser safety equipment, you should use the actual wavelength specification rather than rounding it to a more familiar wavelength.

A 1070 nm fiber laser should not simply be treated as a 1064 nm laser because the wavelengths are close.

This does not mean that completely different protective equipment will always be required.

A single laser safety filter, window, or barrier may provide appropriate protection across the entire range.

The point is that the published protection range needs to actually include the wavelength you are using.

Wavelength coverage is only one part of selecting laser safety eyewear or a viewing window.

You also need sufficient optical density (OD) at the applicable wavelength.

For example:

OD 6+ @ 1060–1080 nm

communicates two separate pieces of information:

Wavelength range: 1060–1080 nm
​Attenuation: OD 6 or greater throughout the specified range

If you already know that you require a specific OD across a specific wavelength range, compare that requirement directly against the manufacturer's published OD specifications.

If the required OD has not yet been established, it should be determined as part of the laser hazard evaluation based on the actual system and reasonably foreseeable worst-case exposure conditions.

As part of that evaluation, the LIA Optical Density Calculator may be helpful for evaluating OD requirements.

The most important concept is simple:

1064 nm, 1070 nm, and 1080 nm are close together—but they are not interchangeable specifications.

This applies to more than just these three wavelengths.

Whenever selecting laser safety equipment, compare the actual laser wavelength or wavelength range with the manufacturer's published protection specifications.

Do not assume protection based solely on:

1064 nm, 1070 nm, and 1080 nm are all invisible near-infrared laser wavelengths, and a single protective product may provide appropriate protection across all three.

However:

Protection at 1064 nm ≠ automatically protection at 1070 nm or 1080 nm.

Verify the actual operating wavelength or wavelength range of the laser.

Then make sure the laser safety eyewear, viewing window, barrier, or other protective equipment has published specifications appropriate for that wavelength.

Nearby wavelengths may fall within the same protective range—but verify the specification rather than assuming they do.