Thin Film Laser Damage Competition 2021 at SPIE Laser Damage

Coordinated by Raluca A. Negres, Christopher J. Stolz, Lawrence Livermore National Lab. (USA)

Femtosecond 515-nm Mirror Thin Film Damage Competition

A double-blind laser damage competition will be held to determine the current laser damage resistance of 515-nm, normal incidence multilayer mirrors in the femtosecond pulse regime. The results will be shared at SPIE Laser Damage 2021.

Thin Film Laser Damage Competition

The mirrors must meet the following requirements:

  • Reflectance > 99.5%
  • Wavelength 515 nm
  • 0 degrees incidence angle
  • Pulse length 200-fs; Repetition rate 5 kHz
  • No GDD specifications
  • Environment: Ambient air
  • No wavefront or stress requirement
  • No surface quality requirement

This is a continuation of 2020 nanosecond laser, 532-nm damage competition. Any new sample submittals must be preapproved by Raluca Negres, Coatings received in 2020 will be angle-tuned for damage testing at 25 degrees to account for the large wavelength shift. The coatings shall be deposited on glass substrates provided by the coating supplier. The dimensions of the substrate shall be 50 mm (+/- 1 mm) in diameter and at least 10 mm thick.

Testing will be performed by:


Anonymity and requirements

Each sample will be assigned a unique label to maintain anonymity. The origin of the samples will not be released to the damage testing service and also will not be published at the Laser Damage Symposium or within the proceedings. A summary of the results will be published in the conference proceedings. Coating suppliers will be informed of the measured results and relative ranking within the submitted population. In order to minimize the number of damage tests, no more than two different samples can be submitted from each coating supplier.

  • In addition to the sample, the coating supplier MUST also supply the following information:
  • Coating materials and number of layers
  • Reflectance or transmission spectral scan (prefer in an electronic format) in 400 - 600 nm range. Spectral scans may be emailed to
  • A brief description of the deposition method (e-beam, IAD, IBS, plasma assist, etc.)
  • Substrate material and cleaning method

Failure to provide the required information will result in disqualification of the sample. If two samples are submitted, the vendor must describe the manufacturing differences between the two samples. Optical or scanning electron microscopy may be used to image damage sites. Reflectance measurements may also occur. No other characterization tools will be used on the samples to protect any proprietary features of the samples.