An improvement in light confinement in sapphire fiber is obtained by employing nanoporous alumina as a cladding. The fabrication strategy entails freeze-coating metal Al on sapphire fiber and its subsequent anodization to form alumina cladding with highly organized nanopore channels vertically aligned to the fiber axis with dimensions of ~20 nm. We investigated the confinement dependence on the porosity of the cladding, showing an improvement in comparison to unclad sapphire fibers. The versatility of anodized alumina cladding with tunable structural and optical characteristics has the potential to enable a new class of specialty sapphire optical fibers by engineering the light propagation for new sensor development.

Date Published: 27 April 2017
PDF: 5 pages
Proc. SPIE 10208, Fiber Optic Sensors and Applications XIV, 102080A (27 April 2017); doi: 10.1117/12.2262663

Published in SPIE Proceedings Vol. 10208:
Fiber Optic Sensors and Applications XIV
Christopher S. Baldwin; Gary Pickrell; Henry H. Du, Editor(s)