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Updated: Feb 2, 2026

Writing Bragg Gratings in Multicore Fibers
Published on: April 20, 2016
Long Period Grating-Based Fiber Coupling to WGM Microresonators
Francesco Chiavaioli1, Dario Laneve2, Daniele Farnesi3
1Institute of Applied Physics "Nello Carrara" (IFAC), National Research Council of Italy (CNR), Via Madonna del Piano 10, Sesto Fiorentino, 50019 Firenze, Italy. f.chiavaioli@ifac.cnr.it.
Abstract:
A comprehensive model for designing robust all-in-fiber microresonator-based optical sensing setups is illustrated. The investigated all-in-fiber setups allow light to selectively excite high-Q whispering gallery modes (WGMs) into optical microresonators, thanks to a pair of identical long period gratings (LPGs) written in the same optical fiber. Microspheres and microbubbles are used as microresonators and evanescently side-coupled to a thick fiber taper, with a waist diameter of about 18 µm, in between the two LPGs. The model is validated by comparing the simulated results with the experimental data. A good agreement between the simulated and experimental results is obtained. The model is general and by exploiting the refractive index and/or absorption characteristics at suitable wavelengths, the sensing of several substances or pollutants can be predicted.
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