Mitigation of laser damage growth in fused silica NIF optics with a galvanometer scanned CO<sub>2</sub> laser

Isaac L. Bass; Vaughn G. Draggoo; Gabriel M. Guss; Richard P. Hackel; Mary A. Norton

doi:10.1117/12.669393

7 June 2006 Mitigation of laser damage growth in fused silica NIF optics with a galvanometer scanned CO₂ laser

Isaac L. Bass, Vaughn G. Draggoo, Gabriel M. Guss, Richard P. Hackel, Mary A. Norton

Proceedings Volume 6261, High-Power Laser Ablation VI; 62612A (2006) https://doi.org/10.1117/12.669393
Event: High-Power Laser Ablation 2006, 2006, Taos, NM, United States

Abstract

Economic operation of the National Ignition Facility at the Lawrence Livermore National Laboratory depends on controlling growth of laser damage in the large, high cost optics exposed to UV light at 351 nm. Mitigation of the growth of damage sites on fused silica surfaces greater than several hundred microns in diameter has been previously reported by us using galvanometer scanning of a tightly focused 10.6 μm CO₂ laser spot over an area encompassing the laser damage. Further investigation revealed that fused silica vapor re-deposited on the surface as "debris" led to laser damage at unexpectedly low fluences when exposed to multiple laser shots at 351 nm. Additionally, laser power and spatial mode fluctuations in the mitigation laser led to poor repeatability of the process. We also found that the shape of the mitigation pit could produce downstream intensification that could damage other NIF optics. Modifications were made to both the laser system and the mitigation process in order to address these issues. Debris was completely eliminated by these changes, but repeatability and downstream intensification issues still persist.

Citation Download Citation

Isaac L. Bass, Vaughn G. Draggoo, Gabriel M. Guss, Richard P. Hackel, and Mary A. Norton "Mitigation of laser damage growth in fused silica NIF optics with a galvanometer scanned CO₂ laser", Proc. SPIE 6261, High-Power Laser Ablation VI, 62612A (7 June 2006); https://doi.org/10.1117/12.669393

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