Design of a Topas-based ultrahigh-sensitive PCF biosensor for blood component detection

Abstract

Detection of blood is very crucial as well as sensitive due to its importance in human body. In this manuscript, a hollow core Topas-based photonic crystal fiber (PCF) biosensor is proposed for sensing in terahertz frequency range. In the hexagonal cladding structure of this proposed biosensor, identical square-shaped air cavities in both the core and cladding are the building blocks. Different analytes such as red blood cell (RBC), hemoglobin, white blood cell (WBC), plasma and water are used to fill the core. The sensing features of the design will be examined using the finite element method. From the simulation results using COMSOL v5.3a software, achieved sensitivity for RBC is 99.39%, for hemoglobin is 99.27%, for WBC is 99.12%, for plasma is 99.03% and for water is 98.79% for y-polarization at optimum design conditions. In addition to sensitivity, the proposed design has the lowest confinement loss for RBC, hemoglobin, WBC, plasma and water of 1.124 × 10−15 dB/cm, 9.557 × 10−16 dB/cm, 7.242 × 10−15 dB/cm, 1.114 × 10−16 dB/cm and 2.515 × 10−15 dB/cm, respectively, in the frequency range from f = 2 to 5 THz. In accumulation to these, the design also shows negligible effective material loss, significant birefringence, enhanced effective area, large beam divergence and very low and flattened dispersion at optimum design conditions. The superior detecting capability and simple geometry of this projected PCF biosensor make it a worthy candidate for use in different practical applications.