Moisture adsorption effects in biaxial and chiral optical thin film coatings

Ian J. Hodgkinson; Qihong Wu; Kathryn M. McGrath

doi:10.1117/12.351251

30 June 1999 Moisture adsorption effects in biaxial and chiral optical thin film coatings

Ian J. Hodgkinson, Qihong Wu, Kathryn M. McGrath

Proceedings Volume 3790, Engineered Nanostructural Films and Materials; (1999) https://doi.org/10.1117/12.351251
Event: SPIE's International Symposium on Optical Science, Engineering, and Instrumentation, 1999, Denver, CO, United States

Abstract

Thin film form birefringence depends on the shape or bunching of nanostructural columns and on the difference in the refractive indices of the columns and the surrounding voids. When moisture from the atmosphere enters the nanostructure the linear form birefringence may decrease by a large amount, of the order of 50%. However, current data refers to tilted-columnar films. We report here on moisture penetration effects in films fabricated by serial bideposition and engineered for large linear form birefringence or large circular form birefringence. As well, we consider post-deposition processes that may retard the uptake of moisture. Vacuum deposition results in oxygen deficient surfaces which rapidly absorb oxygen from the atmosphere either in the form of O₂ or H₂O. In order to retard water uptake this deficiency must be reduced, possibly by annealing samples in an oxygen rich atmosphere subsequent to deposition. Alternatively, surface oxide and hydroxyl groups can be rendered hydrophobic via reaction with silane derivatives. Both methods have been tested for their effectiveness in retarding water uptake.

Citation Download Citation

Ian J. Hodgkinson, Qihong Wu, and Kathryn M. McGrath "Moisture adsorption effects in biaxial and chiral optical thin film coatings", Proc. SPIE 3790, Engineered Nanostructural Films and Materials, (30 June 1999); https://doi.org/10.1117/12.351251

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available