Since the introduction of optical fiber technology in the field of sensor based on the technique of surface plasmon resonance (SPR), fiber-optic SPR sensors have witnessed a lot of advancements. This paper reports on the past, present, and future scope of fiber-optic SPR sensors in the field of sensing of different chemical, physical, and biochemical parameters. A detailed mechanism of the SPR technique for sensing purposes has been discussed. Different new techniques and models in this area that have been introduced are discussed in quite a detail. We have tried to put the different advancements in the order of their chronological evolution. The content of the review article may be of great importance for the research community who are to take the field of fiber-optic SPR sensors as its research endeavors.

In the present work, we have investigated the capability of different bimetallic combinations to be used in a fiber optic sensor based on the technique of surface plasmon resonance. The metals considered for the present analysis are silver, gold, copper, and aluminum. The performance of the sensor with different bimetallic combinations is evaluated and compared numerically. The performance is analyzed in terms of three parameters: sensitivity, signal-to-noise ratio (SNR), and operating range. On the basis of the comparison and some logical criteria, the best possible bimetallic combination along with requisite thickness distribution is predicted. The bimetallic combination is capable of simultaneously providing the larger values of sensitivity, SNR, and operating range, which is not possible with any single metallic layer.

A high-accuracy aluminum-based surface plasmon resonance (SPR) chalcogenide sensor is proposed for IR. The structure is based on widely used 2S2G chalcogenide glass with aluminum as the SPR active metal. The angular interrogation method has been used to study the performance of the sensor in terms of intrinsic sensitivity (IS) that includes the width and shifts of the SPR curve for a given refractive index of sensing layer. The IS of Al-based chalcogenide glass sensor is almost 400% more as compared with an Au-based one, which is the most widely used SPR active metal. The oxidation problem of an Al-based SPR sensor has been addressed.

Sensitivity enhancement of surface plasmon resonance (SPR) sensor is proposed utilizing two-dimensional blue phosphorene/molybdenum disulphide (i.e., BlueP/MoS2) heterostructure as an interacting layer with analyte. The analysis indicates that the proposed sensor design provides significantly higher sensitivity in comparison to conventional as well as graphene-based SPR sensors. Combined effect of number of heterostructure layers and light wavelength on sensitivity is also analyzed. The results will open a new way to BlueP/MoS2 heterostructure based SPR sensor for bio- and gas-sensing applications in visible and near infrared spectral regions.