Abstract
U-shaped tight curvatures in optical fibers lead to resonant couplings between the fundamental and higher order modes that are sensible to different parameters, such as strain or temperature, for example. The optical response of the sensor consists on the shift of the resonant wavelength of the coupling. In the case of singlemode fibers, the coupling involves a so-called “cladding mode” and, due to its evanescent field, the curved region will be sensible to changes in the external medium, as well. In this paper, we present the fabrication and characterization of a robust, easy-to-make, U-shaped fiber sensor based on singlemode telecom fiber and its application for biosensing. The resonant nature of the sensing mechanism presents the advantage of large dynamic ranges for RI variations without the ambiguity of other techniques such as interferometry. We studied the performance of the U-shaped fiber sensor for different bending radii, to optimize its sensitivity and detection limit at 1550 nm operation wavelength, as well as the effect of temperature on its response. The shift of the resonant wavelength was measured in detail as a function of the external RI within the range [1.33-1,37]; the detection limit was established in (2.88 ± 0.03) × 10−5 RIU. Furthermore, the device was successfully tested as a proof of concept biosensor, using a system model antigen-antibody (BSA-aBSA).
PDF Article
More Like This
Design and analysis of a weakly coupled few-mode hollow-core U-shaped tube nested antiresonant fiber
Jie Ou, Jianping Li, Weiqin Zheng, Yuwen Qin, Ning Lin, Ou Xu, Quandong Huang, Di Peng, Meng Xiang, Yi Xu, and Songnian Fu
J. Opt. Soc. Am. B 40(5) 1170-1181 (2023)
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription
Add to BibSonomy