Infiltration in Composite Materials Polymer Matrix Using a Self-Interference Long Period Fiber Sensor

The concentration of infiltrated water molecules into polymer matrix of composite materials is an important mechanical and chemical functional parameter of smart composite materials during exploitation in various research, medical, industrial, and security applications and it is important to design a setup as simple and as efficient as possible for measuring and monitoring this important parameter. The paper presents simulation/design results obtained using self-interference long period grating fiber sensors in measuring and monitoring the concentration of infiltrated water molecules into polymer composite materials. The investigated long period grating fiber sensors are used as they are or mounted in interferometric setups. Self-interference long period grating fiber sensors are manufactured by inscribing diffraction gratings into or on single mode commercial communication optical fibers and are used in smart composite materials as signal generators of their feedback loop being embedded into the polymer matrix.