Broadband, 920-nm Mirror Thin Film Damage Competition at SPIE Laser Damage

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

Broadband, 920 nm Mirror Thin Film Damage Competition

A double-blind laser damage competition will be held to determine the current laser damage resistance of broadband, near-IR multilayer mirrors designed for ultra-short, pulsed laser operation. Damage testing will be executed at multiple wavelengths within the designed bandwidth of the optics to inform the spectral pulse shape dependence of the overall damage performance. The results will be shared at SPIE Laser Damage 2023.

Thin Film Laser Damage Competition

The mirrors must meet the following requirements:


  • Reflectance > 99.5 % desired at 830-1010 nm
  • GDD <± 50 fs2 target
  • 45 degrees incidence angle; “S’’ polarization or “P”, vendor specified
  • Damage test wavelengths: 860 nm, 920 nm, 960 nm (S or P, depending on optics specifications)
  • Pulse length 25±5 fs; Repetition rate 5 Hz
  • Environment: Vacuum (10-5 torr), 23 ± 2 degrees C
  • No wavefront or stress requirement
  • No surface quality requirement

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 3 mm thick.

Sample submissions


Samples must be received by May 15, 2023 (earlier preferred, no late submissions will be accepted) to the following address:

Raluca Negres, L-470
Lawrence Livermore National Laboratory
7000 East Avenue
Livermore, CA 94550

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 or disclosed at the Laser Damage Symposium. A summary of the results will be published in the conference proceedings. Coating suppliers will be informed of the measured results for their samples and relative ranking within the overall population of samples. 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 750 - 1100 nm range. Spectral scans may be emailed to negres2@llnl.gov
  • A brief description of the deposition method (e-beam, IAD, IBS, plasma assist, etc.)
  • Substrate material and cleaning method
  • Manufacturing differences for multi-sample submissions, if applicable

Failure to provide the required information will result in disqualification of the sample. 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.

Testing will be performed by: Lab. for Laser Energetics, Univ. of Rochester


Univ. of Rochester LLE logo

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 negres2@llnl.gov
  • 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.