ISO S-on-1 LIDT test (21254-1,2)

The most popular LIDT testing regime for pulsed repetitive irradiation is based on ISO 21254 standardized procedure. Indicates optics degradation in time.

Use this test for:

  • Specification of “typical” LIDT numbers of your optics;
  • Characterization of “fatigue-driven” laser damage to see if optics performance is changing in time;
  • Investigation of possible failure modes (damage mechanisms) that might develop over time;
  • Examination of the optic’s lifetime (in combination with prolonged exposure and data extrapolation);

Test description

The entrance surface of the optical element is divided into a matrix of test sites. Each test site is then exposed to a burst of laser pulses with fixed laser peak fluence. Distinct fluences levels are used for individual test sites. During irradiation sample is monitored for damage: if the damage is detected irradiation is stopped and the dose required to trigger damage is recorded. Otherwise, if samples survive a maximum number of S laser pulses irradiation is stopped for that test site. After exposure, the status of all test sites is also inspected with offline microscopy. Collected damage statistics are then used to calculate LIDT dependence versus the number of applied laser pulses (exposure dose).

Known limitations and risks:

  • Not possible for very limited surface samples (fibers, testing areas <1mm, etc.: use R-on-1 instead);
  • Not repeatable/Overestimates LIDT for samples with a very large aperture (extremely low defect density: use raster scan instead);
  • Testing at very high repetition rates might cause annealing or contaminations of neighboring test sites. Thus, LIDT can be overestimated or underestimated;
  • Testing with less than 1000 pulses is only suited to characterize defect-driven damage mode (long-term degradation effects require a much higher irradiation dose.


Most popular test parameters for this test

Wavelength Pulse duration(1) Repetition rate Pulses per irradiation level Interested?
2100 nm 4 ns 100 Hz 1 000 ORDER
1500 nm 4 ns 100 Hz 1 000 ORDER
1064 nm 10 ns 100 Hz 1 000 ORDER
1064 nm 10 ns 10 Hz 200 ORDER
532 nm 5 ns 100 Hz 1 000 ORDER
355 nm 5 ns 100 Hz 1 000 ORDER
1030 nm 10 ps 1  kHz 10 000 ORDER
1030 nm 180 fs 50 kHz 1 000 000 ORDER
1030 nm 180 fs 100 kHz 1 000 000 ORDER
515 nm 180 fs 50 kHz 1 000 000 ORDER
343 nm 180 fs 50 kHz 1 000 000 ORDER
800 nm 50 fs 1  kHz 10 000 ORDER
Custom Check all availability or configure your own at

(1) effective pulse duration measured at Full Width Half Maximum


Check out our capabilities and identify your system in our “Available testing conditions” table.

Test bundles and packages

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  • Optics Characterization Bundle for CW regime at 1070 nm
    The testing package consists of multiple tests, which are carefully selected to address optics characterization issues at the CW regime.
    Find out more
  • Lifetime + Certification Bundle for Industrial Grade fs-ps Laser Optics
    The package consists of several tests carefully selected to address optics certification for critical applications.
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more tools
and useful information

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  • Testing conditions

    Check out all available laser damage testing conditions (wavelengths, pulse regimes, environments, and more).
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  • Laser Damage infobase

    Check out a useful glossary of terms and simple explanations related to the main topics of laser damage terminology.
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  • Online Fluence calculator

    Check out a calculator equipped with laser-related calculus that is frequently required in practice: such as laser fluence.
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  • Downloads and docs

    Here you can download all information about laser damage testing available at Lidaris.
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  • New client guide

    Here you will find usefull guidlines and suggestions for everyone, who is new the laser damage field.
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  • Orders FAQ

    Fast way to find out about test samples prepration, handling, and shipping
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Feel free to let us know if you have any concerns. We can always help you with choosing the right solution for your specific needs.