Abstract

Fluorescence optical fibre sensors have been successfully demonstrated across a wide variety of applications, such as oxygen sensing and explosives detection [1, 2]. The most established category of these sensors is based on multimode optical fibres (MMF), where the sensing area is the cleaved tip of the fibre [3]. In recent years suspended core fibres (SCFs) have also been used, where a small core is suspended between voids by thin struts. An analyte is filled in the voids running along the length of the fibre and the guided light, of which a small fraction extends evanescently into the voids, and interacts with the analyte. These fibres require minute sample quantities, in the order of a few nanolitres, and have demonstrated detection limits down to a single particle [4]. To the best of our knowledge we present the first direct experimental comparison between tip sensors and SCFs for fluorescence sensing. We show that the suspended core fibre collects a higher fluorescence power per unit of output power from the fibre and therefore have a potential detection limit advantage over MMFs.

© 2015 IEEE