7 - 10 October 2024
San Ramon, CA, US

Femtosecond 1030-nm Mirror Thin Film Damage Competition at SPIE Laser Damage

Coordinated by: Colin Harthcock, Raluca Negres, Lawrence Livermore National Lab. (USA)

Come hear the results of the competition

Participants sent samples to a double-blind laser damage competition to determine the current resistance of 1030-nm, normal incidence multilayer mirrors in the femtosecond pulse regime. The results will be shared at SPIE Laser Damage 2024, Wednesday 9 October during Session 5.

Thin Film Laser Damage Competition

The mirrors must meet the following requirements:

  • Reflectance > 99.5%
  • Wavelength 1030-nm
  • 0 degrees incidence angle
  • Pulse length 200-fs; Variable repetition rate, i.e. 500 kHz vs. 500 Hz
  • No GDD specifications
  • Environment: Ambient air
  • No wavefront or stress requirement
  • No surface quality requirement.

This competition aims to assess the correlation in damage resistance of these 1030-nm HR coatings upon exposure to high vs. low repetition rate laser pulses using ISO S-on-1 LIDT test protocols. The coatings shall be deposited on glass substrates provided by the coating supplier. Please take note of the required substrate dimensions this year: substrates shall be 25 mm (+/- 0.4 mm) in diameter and up to 10 mm thick.

Sample submissions

The deadline to receive samples has now passed. 

See sample requirements below, including anonymity steps to take. 

Testing will be performed by: LIDARIS, LIDT Service

LIDARIS

Sample 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 The origin of the samples will not be released to the damage testing service and also will not be published at the Laser Damage Symposium or within the proceedings.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 (electronic format preferred) in the ~900-1200 nm range. Spectral scans should 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 submit samples with the required dimensions and/or provide the required coating information will result in disqualification from the competition. If two samples are submitted, the participant 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.