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Laser-resistance sensitivity to substrate pit size of multilayer coatings.

ABSTRACT: Nanosecond laser-resistance to dielectric multilayer coatings on substrate pits was examined with respect to the electric-field (E-field) enhancement and mechanical properties. The laser-induced damage sensitivity to the shape of the substrate pits has not been directly investigated through experiments, thus preventing clear understanding of the damage mechanism of substrate pits. We performed a systematic and comparative study to reveal the effects of the E-field distributions and localized stress concentration on the damage behaviour of coatings on substrates with pits. To obtain reliable results, substrate pits with different geometries were fabricated using a 520-nm femtosecond laser-processing platform. By using the finite element method, the E-field distribution and localized stress of the pitted region were well simulated. The 1064-nm damage morphologies of the coated pit were directly compared with simulated E-field intensity profiles and stress distributions. To enable further understanding, a simplified geometrical model was established, and the damage mechanism was introduced.

SUBMITTER: Chai Y

PROVIDER: S-EPMC4890428 | biostudies-other | 2016

REPOSITORIES: biostudies-other

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