Cascaded Fiber Optic SPR Sensor

This chapter delves into the use of cascaded fiber optics for the creation of surface plasmon resonance (SPR) sensors. Great opportunities arise from the ability to sense multiple analytes and channels with cascaded SPR sensors. The focus of this section is a dual-channel SPR refractive index sensor based on a fiber with a modified hetero-core structure. By reshaping the conventional hetero-core structure fiber into a circular truncated cone with a varied polishing angle, the resonance wavelength range can be easily adjusted. The potential of utilizing wavelength division multiplexing with two cascaded fiber optic SPR sensors to simultaneously test two different substances is also explored. A real-world scenario is described, where a cascaded SPR sensor was used to identify a disease by comparing the concentrations of coagulants and anticoagulants using a multi-analyte SPR sensor. Through this comprehensive examination, the capabilities and potential applications of cascaded fiber optic SPR sensors are highlighted, shedding light on their significant contributions to the field of optical sensing.