Abstract
Damage growth in optical materials used in large aperture laser systems is an issue of great importance when determining component lifetime and therefore cost of operation. Understanding the mechanisms and photophysical processes associated with damage growth are important in order to devise mitigation techniques. In this work we examined plasma-modified material and cracks for their correlation to damage growth on fused silica and DKDP samples. We employ an in-situ damage testing optical microscope that allows the acquisition of light scattering and fluorescence images of the area of interest prior to, and following exposure to a high fluence, 355-nm, 3-ns laser pulse. In addition, high-resolution images of the damage event are recorded using the associated plasma emission. Experimental results indicate that both aforementioned features can initiate plasma formation at fluences as low as 2 J/cm 2. The intensity of the recorded plasma emission remains low for fluences up to approximately 5 J/cm 2 but rapidly increases thereafter. Based on the experimental results, we propose as possible mechanisms leading to damage growth the initiation of avalanche ionization by defects at the damage modified material and presence of field intensification due to cracks.
Original language | English (US) |
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Title of host publication | Proceedings of SPIE - The International Society for Optical Engineering |
Editors | G.J. Exarhos, A.H. Guenther, M.R. Kozlowski, K.L. Lewis, M.J. Soileau |
Pages | 277-284 |
Number of pages | 8 |
Volume | 4347 |
DOIs | |
State | Published - 2001 |
Externally published | Yes |
Event | 32nd Annual Boulder Damage Symposium - Laser-Induced Damaged in Optical Materials: 2000 - Boulder, CO, United States Duration: Oct 16 2000 → Oct 18 2000 |
Other
Other | 32nd Annual Boulder Damage Symposium - Laser-Induced Damaged in Optical Materials: 2000 |
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Country | United States |
City | Boulder, CO |
Period | 10/16/00 → 10/18/00 |
Keywords
- DKDP
- KDP
- Laser damage
- Optical breakdown
- SiO
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Condensed Matter Physics