Nanosecond 1900-nm Mirror Thin Film Damage Competition at SPIE Laser Damage

• Reflectance > 99.5%
• Wavelength 1900-nm
• 0 degrees incidence angle
• Pulse length 10-ns
• Environment: Ambient air
• No wavefront or stress requirement
• No surface quality requirement

This competition aims to understand laser damage trends for 1900-nm irradiation wavelength, in the ns pulse duration regime as tested with a mode-locked Tm:YLF laser and utilizing 1cm² area MEL01-013-OD raster specification. 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 50.8 mm (+/- 0.4 mm) in diameter and up to 10 mm thick.

Samples must be received by 1 June 2025 at the following address:

Colin Harthcock, L-465
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 The origin of the samples will not be released to the damage testing service and also will not be published at the Laser Damage Symposium or within the proceedings.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 ~1700-2100 nm range. Spectral scans should be emailed to harthcock1@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.