Implementation of QKD-based system using Nano PCF for healthcare applications

The present paper proposed a design of a Photonic Crystal Fiber (PCF) with a nano-scale coating of very thin gold dielectric rods in the first ring. In such a configuration, the single-ring PCF may act as a bridge or a connector between two multi-ring PCFs on both sides. This arrangement could be used in various optical communications where one is required to interface different types of PCF. Also, it can be used as a sensor for analyte as a blood sample for different patients. The envisioned sensor can identify unknown analytes either by passing through the metal surface or being applied to the outer surface of the metal layer. The single-ring PCF will be infused with blood samples from various patients to monitor changes in ligand and receptor concentrations with temperature. Additionally, this proposed sensor design features symmetrical elliptical gold-dielectric rods, with two small metal-rods in the first ring. These supplementary thin metal-dielectric rods in place of air holes enhance the generation of the evanescent field. This helps in adjusting the phase matching between the cores-guided mode and surface plasmon polaritons (SPP) mode. The sensing mechanism is based on the Quantum Key Distribution (QKD) technique and Surface Plasmon Resonance (SPR) occurring at the interfaces of dielectric-metal contacts. To estimate the dispersion and birefringence of the patterned PCF we employ the Finite Difference Time Domain (FDTD) method. Such research holds significance in the realm of biochemical sensing, offering potential advancements in this field. These simulation result is required to make its experimental validation and immediate applicability in clinical or diagnostic contexts to confirm the real-world feasibility and performance of the proposed PCFs structure in future works.