How to Choose the Right Color for a Laser Safety Window?

With the widespread use of laser technology and laser equipment in various fields, including industrial processing, medical aesthetics, education, and research, laser safety is of paramount importance. Laser safety windows (also known as laser protection panels, laser shielding windows, or laser protective glass) are one of the most important protective tools in laboratories, industrial workshops, and medical facilities. These panels allow operators to observe the laser process while filtering out harmful laser wavelengths. But how do you choose the right laser safety window color? In this article, we'll explain the factors that influence your choice and the relationship between color and laser wavelength protection.

1. Understanding the Role of Color in Laser Safety Windows

The color of laser safety windows is more than just cosmetic—it's directly related to the laser wavelengths they block. Different laser wavelengths correspond to specific colors in the visible spectrum, and the filter materials are dyed to effectively absorb or reflect these wavelengths.

For example:

Green protective panels are typically designed to block red laser light in the 600-700 nm range.

Amber or orange protective panels are typically used to block blue and green laser light in the 400-550 nm range.

Dark red or brown protective windows provide protection against certain infrared laser wavelengths.

Green protective windows provide protection against fiber lasers and some near-infrared lasers.

When selecting laser safety windows, it is important to check the optical density (OD) and wavelength range specifications, rather than relying solely on visible light color.

2. Determine the Laser Wavelength

Before selecting a laser safety window color, determine the exact wavelength of the laser. Common laser types include:

Diode lasers: 405 nm (violet), 450 nm (blue), 650 nm (red)

Nd:YAG lasers: 1064 nm (near-infrared)

Fiber lasers: 1070-1080 nm

CO₂ lasers: 10,600 nm (far-infrared)

Once you have determined the wavelengths you need protection against, you can select a window filter that provides adequate protection.

3. Check the Optical Density (OD) Rating

The OD rating indicates how effectively the protective window attenuates laser light. Higher OD values indicate greater laser attenuation. For example:

OD 4 blocks 99.99% of the specified wavelength.

OD 7 blocks 99.99999% of the specified wavelength.

The window color should always be selected based on the correct OD rating for the specific laser type and power being used.

4. Don't Rely Solely on Color

While visible color can indicate wavelength protection level, it's not an absolute guide. Two windows of the same color can have completely different protection levels depending on the filter material. For example, our two laser safety windows for fiber lasers from LaserPair, while both have green protective plates, have different protection levels (OD ratings).

5. Summary

Choosing the appropriate laser safety window color is about matching the filter's wavelength protection range to the actual laser wavelength being used, not just choosing a favorite color.

Determine the exact wavelength of the laser being used.

Select a window with the appropriate OD rating.

Select a safety window that meets safety certification standards.