Two-dimensional materials (2DMs) have attracted extensive attention as plasmonic materials due to their remarkable electrical and optical performance over the past decade. Similar to graphene, black phosphorus (BP), is reintroduced into the world from the perspective of two-dimensional materials. Engineering and increasing the interaction of matter and light is possible for graphene and phosphorene due to the support of surface plasmon resonance in the infrared regime. Black phosphorus (BP), unlike graphene, has an inherent band gap and provides high potential for optoelectronics. In monolayer BP (called phosphorene), phosphorus atoms covalently bond with the other three to form a hexagonal lattice with a honeycomb structure. In this thesis, due to the anisotropic properties of phosphorene and the difference in its optical directions - zigzag and chair, the effect of curvature on phosphorene is investigated by designing phosphorene nanotubes in the IR range. It was observed that the formation of curvature in the phosphorene monolayer leads to greater adsorption. Then, by designing an unlabeled SPR biosensor based on phosphorene nanotubes, the sensitivity of this sensor to environmental factors has been investigated. Finite-element method (FEM) based COMSOL software is used to investigate the performance of the proposed sensor. It was observed that phosphorene nanotubes show better performance compared to flat phosphorene and showed good ability to identify materials with a refractive index range of 1 to 1.6
with an accuracy of 0.005. Finally, the sensory ability of this sensor for some biomolecules has been investigated. The proposed sensor shows the maximum interrogation sensitivity of 1040 nm / RIU in the dynamic index range from 1 to 1.6. It also shows a maximum quality factore of 818 with an RI of 1.2. Then a photonic
crystal fiber based on a surface plasmon resonance biosensor (PCF-SPR) with a silver-phosphorene layer acting in near infrared is proposed to meas