Epoxy-based broadband antireflection coating for millimeter-wave optics

We have developed epoxy-based, broadband antireflection coatings for millimeter-wave astrophysics experiments with cryogenic optics. By using multiple-layer coatings where each layer steps in dielectric constant, we achieved low reflection over a wide bandwidth. We suppressed the reflection from an...

Full description

Saved in:
Bibliographic Details
Published inApplied optics. Optical technology and biomedical optics Vol. 52; no. 33; p. 8102
Main Authors Rosen, Darin, Suzuki, Aritoki, Keating, Brian, Krantz, William, Lee, Adrian T, Quealy, Erin, Richards, Paul L, Siritanasak, Praween, Walker, William
Format Journal Article
LanguageEnglish
Published United States 20.11.2013
Online AccessGet more information

Cover

More Information
Summary:We have developed epoxy-based, broadband antireflection coatings for millimeter-wave astrophysics experiments with cryogenic optics. By using multiple-layer coatings where each layer steps in dielectric constant, we achieved low reflection over a wide bandwidth. We suppressed the reflection from an alumina disk to 10% over fractional bandwidths of 92% and 104% using two-layer and three-layer coatings, respectively. The dielectric constants of epoxies were tuned between 2.06 and 7.44 by mixing three types of epoxy and doping with strontium titanate powder required for the high dielectric mixtures. At 140 K, the band-integrated absorption loss in the coatings was suppressed to less than 1% for the two-layer coating, and below 10% for the three-layer coating.
ISSN:2155-3165
DOI:10.1364/ao.52.008102