FBG Sensors for Environmental and Biochemical Applications—A Review

Sensors play a large role in monitoring and ensuring that environmental parameters satisfy industrial requirements. They offer crucial safety measures in the early detection of hazards. Conventional electrical sensors possess several drawbacks that hinder their use in environmental sensing. Research has explored and optimized optical-based sensors because they are more robust, immune to electromagnetic interference and offer multiplexing capabilities for sensor arrays accompanied by ease of modification to cater to different measurands. Fibre Bragg grating is the perturbation of the refractive index imprinted within the core of an optic fibre via an intense UV laser. The gratings, when perturbed by external parameter changes, will induce a shift in their wavelength, indicating detection. With modifications such as hygroscopic coating and different grating profile imprinting, FBG can detect various physical and chemical parameters. Environmental, pharmaceutical and biochemical fields can benefit from FBG sensing because their parameters affect not only their product quality but also the lives of consumers. This review discusses some of the FBG sensors that have been proposed to serve in environmental and biochemical applications.