Study of high-performance IBS coatings for near-IR laser applications

Abstract

In many laser applications, there is a higher and higher demand for more efficient coatings with reduced losses, in terms of absorption and scattering as those are contributing factors to diverse laser damage regimes. Ion Beam Sputtering (IBS) is a known technique to provide such high optical quality thin films. Indeed, it allows to achieve high density layers with low absorption and scattering. In this work, various coatings were developed using Bühler IBS technology. Then, total losses were measured using Cavity Ring Down, absorption using Laser Induced Deflection or Laser thermography, and Total Integrated Scatter using dedicated scatterometers. A correlation between the effect of the chosen deposition method and parameters and the measurement performances were made with the aim of a better understanding of the level and the origin of losses in the coatings. Finally, highly reflecting mirror coatings for 1064 nm wavelength were fabricated with different designs and deposition parameters. The results of the different measurements of absorption, scattering and total losses using different equipment are presented and discussed.