Studying condensed phase formed upon interaction between a high-power laser pulse and crystal aluminum oxide

Abstract

Forms of the condensed phase created under the action of a high-power CO₂ laser pulse (power, 4 J/pulse; λ = 10.6 μm; pulse duration, 1.5 μs) on optical sapphire (Al₂O₃) solid targets are investigated. The ablation products emitted from the laser crater and the particles formed in the space above the surface of the target are collected using witness samples oriented in a predetermined manner with respect to the laser crater. Forms of the condensed phase are studied via electron microscopy and atomic force microscopy. Conclusions are drawn as to the mechanisms of formation of particles with different shapes and structures, including Al₂O₃ vacuum hollow microspheres (hollow bubbles).