Humidity sensor based on a long-period fiber grating coated with a Si0_2-nanospheres film

摘要

This work addresses a humidity sensor using long-period fiber gratings (LPG) coated with silica nanospheres film. Si02- nanospheres coating is deposited onto the LPG using the electrostatic self-assembly technique (ESA). The polymeric overlay changes its optical properties when exposed to different humidity levels, resulting in a shift of the resonance wavelength of the LPG. The obtained results are accordant with the theoretical simulations. Wavelength shifts up to 12nm in a humidity range from 20% to 80% are reported, maintaining the same dependence at different temperatures.