Write-Once Optical Recording Property of Amorphous WO<sub>3</sub> Thin Film and its Relative Mechanism

Abstract

Write-once optical recording property of the amorphous WO3 (a-WO3) thin film prepared on the glass substrate by thermal evaporation deposition, has been demonstrated by focusing the laser of 514.5 nm with a variable power to a spot with a size of 1-2μm in diameter on the surface of thin film. The mechanisms responsible for the refractive index change of thin film after the laser recording, has also been studied by monitoring the Raman signal change with the increase of the incident laser power, and by characterizing the micro-structures of the pits induced by laser irradiation. As a result, two mechanisms, the laser-induced phase transition and the laser-induced micro-explosion, are proposed to be responsible for the write-once optical recording.