Scatter Loss From Environmental Degradation of KDP Crystals

Conference · Fri Dec 17 04:00:00 EST 1999

DOI:https://doi.org/10.1117/12.379328· OSTI ID:791060

Wheeler, E K ^[1]; McWhirter, J; Whitman, P K; Thorsness, C; De Yoreo, J; Thomas, I; Hester, M

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1. LLNL

Severe scattering losses from KDP crystals have been correlated with the exposure of porous sol AR coated crystals to ambient humidity. The scattering is attributed to formation of etch pits which develop under the coating on the KDP surface along crystallographic axes. This high angle scattering can in turn produce laser damage of downstream optics either through modulation of the beam or by optic contamination from ablation of adjacent metal structures. We have developed a simple tool to characterize the evolution of scatter from sol-coated KDP surfaces. We have measured the rate of etch pit formation as a function of relative humidity and surface treatment using both microscopy and scattering. We will discuss various surface treatments which can be utilized to retard or eliminate the environmental degradation of KDP crystals.

• Research Organization: Lawrence Livermore National Lab., CA (US)
• Sponsoring Organization: USDOE Office of Defense Programs (DP) (US)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 791060
• Report Number(s): UCRL-JC-134819
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
ABLATION
COATINGS
HUMIDITY
LASER MATERIALS
MODULATION
OPTICS
SCATTERING
SURFACE TREATMENTS