Open AccessReflectivity enhanced refractive index sensor based on a fiber-integrated Fabry-Perot microresonator
Author(s) -
Torsten Wieduwilt,
Jan Dellith,
Florian Talkenberg,
Hartmut Bartelt,
Markus A. Schmidt
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.025333
Subject(s) - finesse , fabry–pérot interferometer , resonator , optics , refractive index , materials science , fiber optic sensor , optical fiber , fresnel equations , optoelectronics , fiber , sensitivity (control systems) , q factor , physics , electronic engineering , wavelength , composite material , engineering
We discuss a fiber-integrated refractive index sensor with strongly improved detection performance. The resonator has been implemented by means of focused-ion beam milling of a step index fiber and shows a sensitivity of about 1.15µm/RIU. Coating the resonator walls led to a strongly improved mirror reflectivity by a factor of about 26. Design rules for device optimization and a detailed mathematical analysis are discussed, revealing that the sensor operates as an optimized Fabry-Perot resonator. We also show that the performance of such kind of Fabry-Perot sensors is, in general, limited by the detection limit function - a quantity depending on the cavitiy's finesse and on the measurement capabilities used.