Laser damage resistant anti-reflection microstructures in Raytheon ceramic YAG, sapphire, ALON, and quartz

Douglas S. Hobbs; Bruce D. MacLeod; Ernest Sabatino III; Thomas M. Hartnett; Richard L. Gentilman

doi:10.1117/12.883272

20 May 2011 Laser damage resistant anti-reflection microstructures in Raytheon ceramic YAG, sapphire, ALON, and quartz

Douglas S. Hobbs, Bruce D. MacLeod, Ernest Sabatino III, Thomas M. Hartnett, Richard L. Gentilman

Proceedings Volume 8016, Window and Dome Technologies and Materials XII; 80160T (2011) https://doi.org/10.1117/12.883272
Event: SPIE Defense, Security, and Sensing, 2011, Orlando, Florida, United States

Abstract

A study of the laser induced damage threshold (LiDT) of anti-reflection (AR) microstructures (ARMs) built in the end facets of metal ion doped yttrium aluminum garnet (YAG) laser gain material, has been conducted. Test samples of undoped and ytterbium-doped polycrystalline YAG produced by Raytheon Company were processed with ARMs in one surface and subjected to standardized pulsed LiDT testing at the near-infrared (NIR) wavelength of 1064nm. As received YAG samples with a simple commercial polish were also submitted to the damage tests for comparison, along with YAG samples that were treated with a single layer thin-film AR coating designed for maximum transmission at 1064nm. Additional samples of single crystal sapphire and quartz, and polycrystalline ALON^TM windows were prepared with thin-film AR coatings and ARMs textures to expand the 1064nm laser damage testing to other important NIR transmitting materials. It was found that the pulsed laser damage resistance of ARMs textured ceramic YAG windows is 11 J/cm², a value that is 43% higher than untreated ceramic YAG windows, suggesting that ARMs fabrication removed residual sub-surface damage, a factor that has been shown to be important for increasing the damage resistance of an optic. This conclusion is also supported by the high damage threshold values found with the single layer AR coatings on ceramic YAG where the coatings may have shielded the sub-surface polishing damage. Testing results for the highly polished sapphire windows also support the notion that better surface preparation produces higher damage resistance. The damage threshold for untreated sapphire windows exceeded 32 J/cm² for one sample with an average of 27.5 J/cm² for the two samples tested. The ARMs-treated sapphire windows had similar damage thresholds as the untreated material, averaging 24.9 J/cm², a value 1.5 to 2 times higher than the damage threshold of the thin film AR coated sapphire windows.

Citation Download Citation

Douglas S. Hobbs, Bruce D. MacLeod, Ernest Sabatino III, Thomas M. Hartnett, and Richard L. Gentilman "Laser damage resistant anti-reflection microstructures in Raytheon ceramic YAG, sapphire, ALON, and quartz", Proc. SPIE 8016, Window and Dome Technologies and Materials XII, 80160T (20 May 2011); https://doi.org/10.1117/12.883272

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available