Optical Fibre Chemical Sensors

This chapter describes the basic principles and mechanisms of main approaches to fibre‐optic‐based chemical sensing including absorption, luminescence, and surface plasmon resonance. It summarizes the basic principles and mechanisms of each approach and also describes specific applications in detail, which highlights the critical issues associated with this sensing technology. The chapter presents examples of chemical sensor design and their respective underpinning sensing technologies projected to fulfil specific application requirements. It then specifically describes fibre‐optic sensing systems for pH, mercury, and cocaine. Compared with electrochemical sensors, optical fibre chemical sensors have shown stronger resistance to chemical attacks due to the use of glass sensor substrate. Therefore, they are suitable to be used in harsh environment where contamination may pose a threat to electrochemical sensors. In addition, optical fibre chemical sensors are immune to electromagnetic (EM) interference and thus are suitable to be used in conditions where EM interference is an issue.