Ultrasensitive plasmonic sensing in air using optical fibre spectral combs

作者：Caucheteur, Christophe^*; Guo, Tuan^*; Liu, Fu; Guan, Bai-Ou; Albert, Jacques^*

来源：Nature Communications, 2016, 7(1): 13371.

DOI：10.1038/ncomms13371

• RESONANCE SENSORS
• REFRACTIVE-INDEX

Surface plasmon polaritons (SPP) can be excited on metal-coated optical fibres, enabling the accurate monitoring of refractive index changes. Configurations reported so far mainly operate in liquids but not in air because of a mismatch between permittivities of guided light modes and the surrounding medium. Here we demonstrate a plasmonic optical fibre platform that overcomes this limitation. The underpinning of our work is a grating architecture-a gold-coated highly tilted Bragg grating-that excites a spectral comb of narrowband-cladding modes with effective indices near 1.0 and below. Using conventional spectral interrogation, we measure shifts of the SPP-matched resonances in response to static atmospheric pressure changes. A dynamic experiment conducted using a laser lined-up with an SPP-matched resonance demonstrates the ability to detect an acoustic wave with a resolution of 10(-8) refractive index unit (RIU). We believe that this configuration opens research directions for highly sensitive plasmonic sensing in gas.

• 出版日期2016-11-11
• 单位暨南大学