Laser Safety Glasses Wavelength Classification

Laser safety glasses are crucial for anyone using laser devices, whether in manufacturing, medical, scientific research, or beauty fields. However, not all laser safety glasses protect against the same wavelengths, and not every pair protects against all laser wavelengths. Each laser operates at a different wavelength (measured in nanometers), and the safety glasses must be perfectly matched to that wavelength to ensure safety. This article explains the main wavelength classifications of laser safety glasses, how they work, and how to choose the correct wavelength range for your laser applications.

The Importance of Wavelength Classification

Laser safety glasses do not block all lasers.

Instead, they are designed to protect against specific wavelengths of laser light.

If the glasses have a very high optical density (OD) but their wavelength does not match the laser wavelength, they will not provide any protection.

Therefore, understanding wavelength classification is the first and most important step in choosing laser safety glasses.

Furthermore, different laser wavelengths cause varying degrees of damage to our eyes, specifically:

Ultraviolet lasers (100-400nm) typically damage the cornea and lens;

Lastics in the 400-1400nm wavelength range can directly penetrate the lens of the eye, damaging the retina and even the optic nerve, causing irreversible damage;

Lastics in the wavelength range above 1400nm cause similar damage to the eye as ultraviolet lasers, primarily affecting the cornea and lens.

Main Wavelength Classifications of Laser Protective Glasses

① Ultraviolet Laser Protection (180–400 nm)

Common ultraviolet laser wavelengths include:

266 nm (Fourth harmonic YAG laser)

355 nm (Third harmonic YAG laser)

Applications: Semiconductor processing, microfabrication, research laboratories.

② Visible Laser Protection (400–780 nm)

These wavelengths fall within the visible light spectrum. Typical lasers include:

445–450 nm blue lasers

532 nm green Nd:YAG harmonic lasers

Applications: Alignment, engraving, entertainment lasers, biotechnology.

Red Light (620–700 nm): Helium-neon lasers (laboratory research) and diode lasers (laser indicators, barcode scanners)

Glasses used in the visible light band are often tinted because they selectively absorb specific colors corresponding to the laser emission.

③ Near-Infrared (NIR) Laser Protection (780–1400 nm)

This is one of the most common laser categories. Typical lasers include:

808 nm, 980 nm diode lasers

1064 nm fiber/YAG lasers

1310/1550 nm telecommunications lasers

Applications: welding, cutting, marking, medical aesthetics, scientific research.

NIR lasers are extremely dangerous because they are invisible to the human eye but can penetrate deep into tissues. Therefore, choosing the appropriate wavelength coverage is crucial.

④ Mid-Infrared Laser Protection (1400–3000 nm)

This band includes:

Er:YAG (2940 nm)

1420–1550 nm Raman lasers

Applications: dentistry, dermatology, medical treatments. Mid-infrared wavelengths are strongly absorbed by water, so wearing inappropriate goggles can cause rapid corneal damage.

⑤ Far-Infrared/CO2 Laser Protection (10,600 nm)

The emission wavelength of CO2 lasers is:

10.6 μm (10,600 nm)

Applications: Cutting, engraving, surgery.

Multi-Wavelength Protection

Some laser protective glasses are designed to block multiple wavelength ranges. For example, our LP-GTY laser safety glasses (180 - 532nm OD 5+ 900 - 1080nm OD 5+) from LaserPair can protect against both 532nm and 1064nm wavelengths.

How to Choose the Correct Wavelength Category

To ensure proper laser protection, please follow these steps:

① Determine your laser wavelength. If you need protection against 532nm green lasers, choose our LP-GHP laser protective glasses from LeiPing Technology; if you need protection against 10600nm CO2 lasers, choose our LP-CHP laser protective glasses from LeiPing Technology.

② Match the wavelength range printed on the glasses.

The label should clearly show the precise nanometer count or range.

③ Check the required optical density (OD)

Higher power → Higher optical density

Lower power → Lower optical density

④ Check certification information

Choose laser safety glasses that meet certification standards such as EN 207, ANSI Z136, or GB 30863, as these standards ensure the glasses have been tested under actual laser irradiation conditions and provide real protection.

Conclusion

When choosing laser safety glasses, wavelength category should be considered first, followed by optical density value.

There are no "universal laser glasses"—each pair protects against specific wavelengths of laser light.

By understanding the classification of ultraviolet, visible, near-infrared, mid-infrared, and carbon dioxide, laser operators can correctly select appropriate laser safety glasses for the laser systems they are using, ensuring reliable eye protection.