In this study, the possibility to excite Bloch surface waves (BSWs) on the tip of a single-mode optical fiber is explored for the first time. In particular, we first show the possibility to achieve an on-tip excitation of BSWs, with optimized characteristic of the arising resonances, via an “all-fiber” grating-coupled configuration. Furthermore, envisioning novel high-performance fiber tip nanoprobes for label-free biosensing, we introduce an ad hoc design aimed at maximizing the refractive-index sensitivity. Numerical results indicate that the estimated sensitivities are comparable with those exhibited by current plasmonic lab-on-tip bio-probes, but are accompanied by a higher spectral selectivity. Therefore, this preliminary work paves the way to the development of new classes of miniaturized surface-wave optical fiber devices for low-detection-limit label-free chemical and biological sensing.

Date Published: 30 May 2016
PDF: 4 pages
Proc. SPIE 9916, Sixth European Workshop on Optical Fibre Sensors, 99161L (30 May 2016); doi: 10.1117/12.2236675

Published in SPIE Proceedings Vol. 9916:
Sixth European Workshop on Optical Fibre Sensors
Elfed Lewis, Editor(s)