Femtosecond Laser Written Plane-by-Plane Bragg Grating Sensors in Bioresorbable Phosphate Optical Fibres

Antreas Theodosiou, Diego Pugliese, Edoardo Ceci-Ginistrelli, Nadia G. Boetti, Davide Janner, Daniel Milanese, and Kyriacos Kalli


We report on the realization of different types of optical sensors in a bioresorbable phosphate glass optical fibre using a femtosecond laser operating at 517 nm. We inscribed fibre Bragg grating-based optical filters such as uniform Bragg gratings, chirped gratings and Fabry-Perot cavities, using the plane-by-plane direct write inscription. The gratings were characterised in reflection and tested as sensors for temperature and relative humidity. We studied the stability and resilience of the gratings when inserted in high humidity environments (> 95%) for 52 h and observed the evolution of the grating characteristics during this period.

Published in Journal of Lightwave Technology – https://www.osapublishing.org/jlt/abstract.cfm?uri=jlt-37-10-2363