Fiber Optic SPR Sensor—Past, Present, and Future

In this chapter, we look at how, over the past three decades, the surface plasmon resonance sensor has outperformed the more traditional interferometric method. SPR sensors provide promising advantages in the realm of chemical and biological sensing, especially when compared to traditional sensing techniques. Several variations on the surface plasmon sensor architecture and detection methods have been published. Sensitivity, input signal range, precision, highest resolution, accuracy, offset error, linear characterization, hysteresis loss, repeatability of approach, and drift due to electronic components are all fundamental parameters to consider when analyzing the performance of a sensing system. Conventional interferometric-based structures, including the Mach–Zehnder interferometer, the Michelson interferometer, the Sagnac loop interferometer, and the Fabry–Perot interferometer, have their working principles discussed before moving on to the various structures and detection techniques involved in surface plasmon resonance. Also discussed are the many techniques for coupling and detecting SPR. Prism-coupled, grating-coupled, and waveguide-coupled SPR are the most popular coupling configurations. After covering the basic details of the working principle, coupling configuration, detection scheme, and various design parameters, the application of surface plasmon resonance is discussed in various aspects of sensing. In the last section of this chapter, the content of the book is briefly discussed.