@inproceedings{2e978a85f8b24297947839a354e903ee,
title = "Sapphire fiber optic-based surface-enhanced Raman scattering by direct and evanescent-field excitation",
abstract = "We present a study on surface-enhanced Raman scattering (SERS) utilizing unclad single crystal sapphire fiber with Ag nanoparticles (NPs) immobilized either at the fiber distal end for direct excitation or on the fiber surface for evanescent-field interaction. The dependence of SERS intensity on the coverage density of Ag NPs was investigated. We demonstrated robust SERS sensitivity in both cases. For direct excitation-based sensing, we found that a sensitivity maximum exists with increased particle coverage beyond which the sensitivity starts to decline. More importantly though, for evanescent-field based measurements, we revealed that multimode sapphire fiber can accommodate Ag NPs at a far higher particle coverage density than single-mode fiber while maintaining the dominance of SERS gain despite competitive absorption and scattering loss by Ag NPs with a limit of detection of 10-9 M Rhodamine 6G solution.",
keywords = "Raman spectroscopy, SERS, direct excitation, evanescent-field, fiber optic sensors, nanoparticles, single crystal sapphire fiber",
author = "Hui Chen and Fei Tian and Jingmao Chi and Henry Du",
year = "2014",
doi = "10.1117/12.2053433",
language = "English",
isbn = "9781628410358",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
booktitle = "Fiber Optic Sensors and Applications XI",
note = "Fiber Optic Sensors and Applications XI ; Conference date: 08-05-2014 Through 09-05-2014",
}