LIDT Challenge 2023 All you need to know about LIDT and the quality of your samples

The HiLASE Centre would like to invite you to participate in the annual LIDT Challenge. In this competition, we are going to test the samples of your anti-reflective coated windows. As a reward, you will gain qualified knowledge of the respective damage thresholds of your components.
LIDT Challenge 2023

Why should you take part?

The reliability of high-power lasers is largely determined by the optical components used in them. Therefore, knowledge of the quality of used components is essential for the safe and reliable operation of laser systems.

How to participate & Conditions

Each participant may provide up to two different samples accompanied by identical control samples (i.e. four samples in total), packed separately and clearly identified. Samples of anti-reflective coated windows from each participant are requested to be sent no later than by the 14th of April 2023 to the following address:


Institute of Physics of the Czech Academy of Sciences
Za Radnici 828 252 41 Dolni Brezany
Czech Republic

The requested diameter of the samples is 2” or 50 mm, with an angle of incidence at 0°. The central wavelength of the coating should be 343 nm and all samples must be coated from both sides. The minimum required thickness of the samples is no less than 3 mm. Anonymized samples will be tested by the s-on-1 method according to the ISO 21254-2:2011 standard with up to 105 pulses. The testing laser will provide 1-ps pulses per round, Gaussian beam with a 1 kHz repetition rate. The beam will be in single-longitudinal mode, p-polarized, and the test will be conducted at ambient pressure, 22°C temperature and 30% relative humidity, i.e. 101.3 kPa, 22°C and 30% respectively. The testing spot size will be 1 mm in the plane of incidence with a maximum fluence of 2.5 J/cm2.
Please make sure that your samples are properly packed and identified, to prevent any transport interference or confusion with other samples. Also, please make sure that every sample you send is accompanied by its identical duplicate, which can be used as a control sample if needed. Please mark your package clearly with the note “LIDT competition” to prevent any confusion with other shipments we are receiving.

What will happen next?

You will have a unique opportunity to see the real-life performance of your elements in the cutting-edge system. Anonymized results will be presented at the Laser World of Photonics, Munich (27. – 30. June 2023) at the planned Laser Technologies workshop of the Czech Optical Cluster, which the HiLASE Centre is a part of, and later directly to the participants.

Why use testing at the HiLASE Centre?

After the successful first year of the HiLASE LIDT Challenge, we would like to progress further and take on a more demanding mission. Previous LIDT tests of high reflective mirrors gave both us and the participants an important insight into how these specific components perform at high laser energies. This year, we would like to reproduce last year’s scheme on different components – laser windows equipped with anti-reflective coatings on both sides. Again, we will use our high-energy, high repetition rate laser system PERLA to introduce large-spot test in combination with long-term exposure and our ISO-certified LIDT station.

To register, please contact us at and