Raster scan LIDT test

Testing procedure, which helps to detect rare defects, which could be missed by applying standard S-on-1 test. It characterizes the worst-case scenario when it comes to large optics and defect-driven damage.

Raster Scan Test explained:

Use this test for:

  • To test samples with low-density (rare) defects;
  • To measure damage density as a function of irradiation level (typically fluence or irradiance);
  • To study conditioning, annealing, or laser cleaning effects;
  • To study laser damage growth;
  • To test/certify large optics;

Test description

During the sub-aperture raster scan test LIDT of the sample is investigated by performing covering large fraction of test sample. A selected area of the sample is scanned by moving laser beam with a spatial overlap between test sites. Spatial overlap is organized in such a way that at least 90% of peak fluence is applied always within entire test area. Surface is checked by microscope before and after scan. If no damage is detected scan is repeated over the same area with increased peak fluence. Starting from very low irradiation level values, it is linearly or non-linearly increased for every new scan until a damage event is detected or the maximum irradiation level of the system is reached. This test if continued above damage initiation threshold may also provide information about the damage density vs irradiation level. (See report example in Downloads section for details).

Known limitations and risks:

  • No fatigue (incubation) effects are considered;
  • Laser cleaning or conditioning is possible;
  • Usually is time-consuming due to multiple microscopy after every scan;
  • LIDT can be screened by contamination of surface by ablation products or poor handling;

Most popular test parameters for this test

Wavelength Pulse duration(1) Repetition rate Coverage within scan area Interested?
1064 nm 10 ns > 90 % of peak fluence ORDER
532 nm 5 ns > 90 % of peak fluence ORDER
355 nm 5 ns > 90 % of peak fluence ORDER
Custom Check all availability or configure your own at my.lidaris.com

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


Check out all available testing capabilities. 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.
    Find out more

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).
    Find out more
  • Laser Damage infobase

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

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

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

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

    Fast way to find out about test samples prepration, handling, and shipping.
    Find out more


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.