Fabrication and Characterization of Erbium-Doped Fluoropolymer Patterns via UV-Nanoimprint Lithography for Use in Planar Optical Amplifiers

Abstract

The Er-doped precursor solutions were first prepared using 2,2,3,3,4,4,5,5-octafluoropentyl acrylate as a fluoromonomer, 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol diacrylate as a cross-linking agent, poly(2,2,3,3,4,4,4-heptafluorobutyl acrylate) as a binding polymer, Darocure 4265 as radical photoinitiator and erbium(III) trifluoromethane sulfonate as an erbium source with various weight ratios. The crosslinked, patterned and erbium-doped fluoropolymer films were fabricated by UV-nanoimprint lithography on glass substrates for application as planar optical amplifiers. The fluoropolymer films acting as a host material for the Er ions showed excellent transmission properties—more than 80% over the visible and near-infrared regions—a high thermal decomposition temperature greater than 350°C and the ability to support a high Er concentration—up to 10 wt% based on the polymer matrix. These results were good enough for the films to be used in planar optical amplifier applications.