STP759

    1.06 μm Laser-Induced Breakdown of CO2-Laser-Polished Fused SiO2

    Published: Oct 1981


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    Abstract

    Fused silica surfaces have been treated with continuous wave CO2-laser radiation in an improved raster technique. Laser damage data for 1.06-μm, 9-nsec, small-spot irradiation are presented. It is shown that a reasonably sharp transition from laser damage prone to laser damage resistant surfaces takes place over a small CO2-laser power range. The transition to high damage resistance takes place at a silica surface temperature where material flow begins to take place, as evidenced by the onset of residual strain in the CO2-processed part. These data are taken as evidence that microcrack healing is an important mechanism in increased damage resistance in CO2-polished parts. Also presented are data which show that CO2-treated surfaces have a small-spot damage threshold at least as high as the bulk damage threshold of SiO2. In addition, these treated parts show no obvious change in surface appearance, as seen in total internal reflection microscopy. They also show little change in transmissive figure. It is suggested that uniform preheating be used to eliminate the strain presently seen in CO2-treated parts.

    Keywords:

    CO, 2, -laser glazing, CO, 2, -laser polishing, fused silica surface, laser damage, laser polishing, surface laser damage, 1.06-μm.


    Author Information:

    Temple, PA
    Michelson Laboratory, Physics Division, Naval Weapons Center, China Lake, California

    Soileau, MJ
    Michelson Laboratory, Physics Division, Naval Weapons Center, China Lake, California


    Paper ID: STP37008S

    Committee/Subcommittee: F01.02

    DOI: 10.1520/STP37008S


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