Product Code: ICAL09_M806

Superstructure Fiber Bragg Grating Sensors with Enhanced Sensitivity using Laser Assisted Direct Writing of On-fiber Thin Films
Authors:
Hamidreza Alemohammad, University of Waterloo; Waterloo ON Canada
Ehsan Toyserkani, University of Waterloo; Waterloo ON Canada
Presented at ICALEO 2009

The present paper is concerned with improving the sensing performance of optical fiber Bragg gratings (FBG) through the design and fabrication of periodic metallic thin films around optical fibers for the realization of superstructure FBGs (SFBG). Periodic metallic layers are designed in such way that when the fiber is placed in structural or thermal fields, the index of refraction is selectively modified as a result of photo-elastic and thermo-optic effects. This can eliminated the linear coupling of the effects of temperature and structural loading in the spectral response of FBGs. Laser-Assisted Maskless Microdeposition (LAMM), which is an additive laser microdeposition method, is used to selectively deposit thin films from silver nanoparticles. In this paper, the results of the LAMM process characterization for the fabrication of metallic patterns on non-planar surface of optical fibers are investigated in terms of their morphology, microstructure, and mechanical properties. In addition, as the laser radiation is a major part of the process, the effects of parameters related to the laser treatment of samples are studied separately. The sensitivity analysis and the capabilities of the sensor for multi-parameter sensing are also investigated.