Environmental Stability of Electron-Beam Deposited Coatings
Hosted By: Thin Films Technical Group
06 July 2021 8:30 - 9:30
Eastern Time (US & Canada) (UTC -05:00)Electron-beam (e-beam) deposited coatings are widely used in high-power laser systems due to their relatively high laser resistance, good spectral uniformity, and ability to scale to large-apertures. The porous nature of the e-beam coating allows the absorption and desorption of water, making the coating susceptible to environmental conditions, especially environmental humidity. The moisture-induced instability of e-beam coating may even lead to the instability of the performance of large laser systems. The performance stability of the e-beam continues to be an essential and challenging work.
In this OSA Thin Films Technical Group webinar, Meiping Zhu from the Shanghai Institute of Optics and Fine Mechanics will discuss the effect of water adsorption on the performance of e-beam HfO2/SiO2 high-reflection coatings by using a dense capping layer to slow the initial rapid water adsorption process. A model based on the effective medium approximation method and the second Fick's law of diffusion is proposed to determine the water vapor transmission rate of the porous e-beam coating. A strategy to improve the environmental stability without sacrificing the laser damage resistance of the e-beam coating is proposed. A low-stress e-beam coating with long-term stability that, which is traditionally difficult to achieve, can be realized by using a plasma ion-assisted deposited SiO2 shell layer to completely isolate the e-beam coating from environmental humidity.
Subject Matter Level: Intermediate - Assumes basic knowledge of the topic
What You Will Learn:
- The effect of water adsorption on the performance of e-beam HfO2/SiO2 high-reflection coating
- Using a dense capping layer to improve the environmental stability of e-beam deposited coatings
- Strategies to improve the long-term stability of low-stress e-beam coatings
Who Should Attend:
- Optical coating engineers and scientists
- Engineers involved in development of optical coating equipment
About the Presenter: Meiping Zhu, Shanghai Institute of Optics and Fine Mechanics
Meiping Zhu holds PhD in Optical Engineering from Shanghai Institute of Optics and Fine Mechanics and a bachelor’s degree from Zhejiang University. She has 16 years of experience in researching laser coatings, including development of optical monitoring systems and enhancement the performance of laser coatings. She has extensive experience in developing coatings with good optical and mechanical properties, and high laser-induced damage thresholds for high power laser systems.
