Birefringent Microstructure Optical Fiber Based Plasmonic Bio-sensor

In this work, a spiral shaped dual polarized microstructure optical fiber (MOF) based plasmonic biosensor with external coating of gold film is proposed. Sensing performance of the proposed sensor for both x- and y-polarized modes are evaluated using finite element method (FEM) in the analyte refractive index (RI) range from 1.35 to 1.41. The birefringent property of MOF helps to enhance the amplitude sensitivity up to 1530 RIU
^-1
in the y-polarized propagation mode while the acquired amplitude sensitivity in the x- polarization mode is 1143 RIU
^-1
. In addition, the proposed sensor exhibits highest wavelength sensitivity of 9000 nrn/RIU, corresponding to the sensor resolution of 1.11 × 10
^-5
RIU for both polarized modes. Furthermore, polynomial fitting of the resonance wavelength gives an excellent value of coefficient of determination (R
²
= 0.9971) which is nearly identical. Owing to having these promising results, the proposed sensor can be implemented in the field of bio-sensing.