Innovative high sensitivity, selectivity, and low birefringence limit based blood cell detection in terahertz spectrum with octagonal core refractive index sensing

Abstract

Biosensors are crucial for identifying different blood components. In this work, we introduce an octagonal core photonic crystal fiber (PCF) structured like a spider for very effective blood cell identification. The Finite Element Method (FEM) in COMSOL Multiphysics is used to investigate the optical and sensing properties of the sensor. Maxwell’s equations are quantitatively solved over the 0.5–1.3 THz frequency range. Achieving high relative sensitivity (RS), low effective material loss (EML), low confinement loss (CL), a large effective area (EA) and spot size for various blood components is the main emphasis of the investigation. Zeonex polymer, well-known for its outstanding THz domain optical characteristics, is used in cladding fabrication of the PCF At 1 THz, the proposed PCF sensor exhibits outstanding performance with a relative sensitivity of around 92.06% for glucose, 92.78% for plasma, 93.45% for white blood cells (WBCs), and 95.64% for red blood cells (RBCs). Since the octagonal core structure produces almost the same results for both x- and y-polarization modes, the research mainly investigates the x-polarization mode.