Abstract

High mechanical stress can affect the performance of multilayer thin film optical coatings, causing wavefront aberrations. This is particularly important if the multilayer stack is deposited onto thin substrates, such as those used in adaptive optics. Stress in thin film coatings is dependent on the deposition process, and ion beam sputtering (IBS) thin films are known to have high compressive stress. In the present work, we show that stress in IBS $ {{\rm SiO}_2} $ thin films can be reduced from 490 MPa to 48 MPa using high-energy $ {{\rm O}_2} $ assist ion bombardment during deposition while maintaining high optical quality. A comparison of the reduction of stress in $ {{\rm SiO}_2} $ deposited from oxide and metal targets is provided.

© 2020 Optical Society of America

Modifications of ion beam sputtered tantala thin films by secondary argon and oxygen bombardment

Le Yang, Emmett Randel, Gabriele Vajente, Alena Ananyeva, Eric Gustafson, Ashot Markosyan, Riccardo Bassiri, Martin Fejer, and Carmen Menoni
Appl. Opt. 59(5) A150-A154 (2020)

Internal stress and optical properties of Nb₂O₅ thin films deposited by ion-beam sputtering

Cheng-Chung Lee, Chuen-Lin Tien, and Jin-Cherng Hsu
Appl. Opt. 41(10) 2043-2047 (2002)

Effect of the working gas of the ion-assisted source on the optical and mechanical properties of SiO₂ films deposited by dual ion beam sputtering with Si and SiO₂ as the starting materials

Jean-Yee Wu and Cheng-Chung Lee
Appl. Opt. 45(15) 3510-3515 (2006)

Influence of dry etching on the properties of SiO₂ and HfO₂ single layers

Lingyun Xie, Huasong Liu, Jun Zhao, Hongfei Jiao, Jinlong Zhang, Zhanshan Wang, and Xinbin Cheng
Appl. Opt. 59(5) A128-A134 (2020)

Mechanical and thermoelastic characteristics of optical thin films deposited by dual ion beam sputtering

Eda Çetinörgü, Bill Baloukas, Oleg Zabeida, Jolanta E. Klemberg-Sapieha, and Ludvik Martinu
Appl. Opt. 48(23) 4536-4544 (2009)