Advances on Photonic Crystal Fiber Sensors and Applications.

In this review paper some recent advances on optical sensors based on photonic crystal fibres are reported. The different strategies successfully applied in order to obtain feasible and reliable monitoring systems in several application fields, including medicine, biology, environment sustainability, communications systems are highlighted. Emphasis is given to the exploitation of integrated systems and/or single elements based on photonic crystal fibers employing Bragg gratings (FBGs), long period gratings (LPGs), interferometers, plasmon propagation, off-set spliced fibers, evanescent field and hollow core geometries. Examples of recent optical fiber sensors for the measurement of strain, temperature, displacement, air flow, pressure, liquid-level, magnetic field, and hydrocarbon detection are briefly described.