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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 15, Iss. 24 — Nov. 26, 2007
  • pp: 16285–16291

Encapsulation of low-refractive-index SiO2 nanorods by Al2O3 with atomic layer deposition

Sangho S. Kim, Nicholas T. Gabriel, Woo-Bin Song, and Joseph J. Talghader  »View Author Affiliations

Optics Express, Vol. 15, Issue 24, pp. 16285-16291 (2007)

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Thin films composed of SiO2 nanorods or nanoporous SiO2 (np-SiO2) are attractive for use as a low refractive index material in various types of optical coatings. However, the material properties of these films are unstable because of the high porosity of the films. This is particularly apparent in dry versus humid atmospheres where both the refractive index and coefficient of thermal expansion (CTE) vary dramatically. In this article, we demonstrate that np-SiO2 can be encapsulated by depositing Al2O3 with Atomic Layer Deposition (ALD), stabilizing these properties. In addition, this encapsulation ability is demonstrated successfully in a 4-pair distributed Bragg reflector (DBR) design. It is hoped that this technique will be useful in patterning specific regions of a film for optical and mechanical stability while other portions are ambient-interactive for sensing.

© 2007 Optical Society of America

OCIS Codes
(120.6810) Instrumentation, measurement, and metrology : Thermal effects
(160.5320) Materials : Photorefractive materials
(160.6840) Materials : Thermo-optical materials
(230.1480) Optical devices : Bragg reflectors
(220.4241) Optical design and fabrication : Nanostructure fabrication

ToC Category:

Original Manuscript: September 4, 2007
Revised Manuscript: October 31, 2007
Manuscript Accepted: November 2, 2007
Published: November 21, 2007

Sangho S. Kim, Nicholas T. Gabriel, Woo-Bin Song, and Joseph J. Talghader, "Encapsulation of low-refractive-index SiO2 nanorods by Al2O3 with atomic layer deposition," Opt. Express 15, 16285-16291 (2007)

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  1. J.-Q. Xi, J. Kyu Kim, E. F. Schubert, D. Ye, T.-M. Lu, and S.-Y. Lin, "Very low-refractive-index optical thin films consisting of an array of SiO2 nanorods," Opt. Lett. 31, 601-603 (2006). [CrossRef] [PubMed]
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