Introduction: This paper demonstrates the design of a sensor model for the detection of
Sodium Chloride (NaCl) in an effective and efficient manner. Photonic Crystal Fiber (PCF) has
been used to design this sensor model.
Objective: Using Comsol Multiphysics software, the sensor model has been implemented and simulated
to carry out an in-depth analysis of the sensing performance of the proposed model.
Methods: The confinement loss, effective material loss, effective area, birefringence, and relative
sensitivity were analyzed to estimate the sensing efficiency of this model. The sensor performance
has been analyzed for five different concentrations of NaCl.
Results: From the analysis, it is found that for all the analytes, confinement loss maintains a moderate
value for the frequency band ranging from 0.9 to 1.2 THz. However, it approaches absolute
zero immediately after 1.2 THz. The sensor model results in a high effective area, which is highly
desirable for every PCF. It shows 3.78 × 105, 3.77 × 105, 3.76 × 105, 3.75 × 105, and 3.743 ×
105 μm2 effective areas for 0%, 20%, 40%, 60% and 80% NaCl, respectively, at 1.4 THz.
The effective material loss for this model is about 3.7×10-3, 3.63×10-3, 3.68×10-3, 3.672×10-3 and
3.652×10-3 cm-1 for 80%, 60%, 40%, 20% and 0% NaCl, respectively, at 1.4 THz. Birefringence
is also high for the proposed model. The values of birefringence are approximately 0.002, 0.0018,
0.0017, 0.0016 and 0.0015 at 1.4 THz for 0%, 20%, 40%, 60% and 80% NaCl, respectively. In addition
to the above positive outcomes, the sensor model exhibits high sensitivity for both x and y
polarization. The peak sensitivity of this sensor is 91.5%, 91.42%, 91.34%, 91.25% and 91.10% in
x polarization direction whereas the peak sensitivity is 91.70%, 91.60%, 91.49%, 91.40% and
91.25% in y polarization direction for 80%, 60%, 40%, 20% and 0% NaCl, respectively, at 1.8
THz. The value of sensitivity is above 90% at 1.4 THz for all the five concentrations of NaCl.
Conclusion: The analyzed optical properties signify the higher efficiency and effectiveness of the
sensor model in the detection of NaCl.