What Is the Difference Between 575 W/cm², 625 W/cm², and 2,250 W/cm² Rated Laser Protection Products?

Laser Safety Industries offers softwall laser protection products with different maximum irradiance ratings. The appropriate option depends on the laser application, potential exposure conditions, containment layout, and hazard evaluation.

Our current softwall options include:

These ratings describe the maximum irradiance the material has been tested to withstand under defined test conditions. They should not be compared directly to the laser's output power in watts.

The primary difference between our 575 W/cm² and 625 W/cm² softwall products is the addition of an extra layer of material in the 625 W/cm² configuration.

This additional layer provides redundancy while increasing the maximum irradiance rating from 575 W/cm² to 625 W/cm².

Our 575 W/cm² and 625 W/cm² softwall materials have been tested at:

Testing was performed for 100 seconds using a 1 mm beam.

These tests establish the material's performance under controlled direct-hit conditions. Actual system selection should be based on the conditions of the specific laser application and hazard evaluation.

For applications where a higher maximum irradiance rating is desired, we also offer a 2,250 W/cm² softwall material.

The 2,250 W/cm² material has been tested at:

Unlike our 575 W/cm² and 625 W/cm² materials, which are used across our broader softwall product offering, the 2,250 W/cm² material is currently available only in our standard 5' × 7' in-stock barrier configuration.

This provides a higher-rated softwall option without requiring a rigid hardwall barrier system.

A higher-powered laser does not automatically require a barrier with an equivalent numerical rating.

For example, a 1,500 W laser does not necessarily require a 1,500 W/cm² barrier.

Laser output power is measured in watts (W), while a barrier's maximum irradiance rating is expressed in watts per square centimeter (W/cm²). Irradiance depends on how much laser power is distributed over a given area at the barrier.

The appropriate barrier therefore depends on factors such as:

A common misunderstanding is that a 1,500 W laser always requires a 1,500 W/cm² rated barrier or curtain.

These two numbers do not represent the same measurement and should not be compared directly.

In practice, laser safety barriers and curtains are generally used for perimeter containment of reflected or diffused laser energy, rather than as beam stops intended to receive sustained direct laser exposure.

To clarify, consider the following illustration demonstrating the critical difference between direct-hit protection and diffused radiation containment:

Although our barriers and curtains are tested under controlled direct-hit conditions for up to 100 seconds, they are primarily intended to contain reflected or diffused laser radiation at the perimeter of a controlled area.

In practice, barriers and curtains are generally used as part of a laser safety system to contain reflected or diffused laser radiation and restrict hazardous exposure outside the controlled area.

Physical containment should be combined with appropriate engineering controls, administrative controls, and personal protective equipment as determined by the laser hazard evaluation.

For additional guidance, please see our Class 4 Laser Safety Guide.

Diffused laser energy spreads as it travels away from the point of interaction, reducing the amount of laser power distributed over a given area.

The illustration below demonstrates how irradiance can decrease with increasing distance from the initial point of interaction:

Laser Energy Diffusion Over Distance

This relationship helps explain why the laser's total output power alone does not determine the irradiance rating required for a perimeter barrier.

For a detailed explanation and the assumptions used when discussing laser energy diffusion and irradiance over distance, please refer to our dedicated Knowledge Base article:

How Laser Energy Diffuses and Decreases with Distance

The 575 W/cm², 625 W/cm², and 2,250 W/cm² ratings describe tested maximum irradiance under specific conditions—not the laser power that each barrier can be used with.

Selecting a higher irradiance rating can provide additional protection margin, but the appropriate rating should ultimately be determined based on the actual laser application, expected exposure at the barrier, and the facility's laser hazard evaluation.