Highly birefringent gold-coated SPR sensor with extremely enhanced amplitude and wavelength sensitivity

In this manuscript, we present a unique and simply designed surface plasmon resonance-based PCF biosensor that shows high sensing performance. The numerical technique finite element method is utilized to evaluate the fiber's guiding characteristics. Our design has a thin layer of gold (Au) surrounding the fiber, which is a stable plasmonic material. The strategic arrangement of the circular-shaped airholes inside the fiber enhances the overall performance of the sensor. After precise investigation of the various fiber parameters, the maximum amplitude sensitivity was found to be 3.35x10(3) RIU-1 for x-polarization and 5.00x10(3) RIU-1 for y-polarization in a sensing range of refractive index 1.33-1.41. The sensor exhibited a maximum birefringence of 2.23x10(-3) and a maximum wavelength sensitivity of 3.00x10(4) nm/RIU and 3.25x10(4) nm/RIU for x- and y-polarization, respectively. The sensor resolution (amplitude) is found to be 2.98x10(-6) for x-polarization and 2.00x10(-6) for y-polarization, whereas the sensor resolution (wavelength) is 3.33x10(-6) and 3.08x10(-6) for x-polarization and y-polarization, respectively. Moreover, we obtained a high figure of merit of 4.48x10(2) RIU-1 for x-polarization and 4.44x10(2) RIU-1 for y-polarization. For its simplicity in design and high performance, this biosensor has a wide range of applications in the field of sensing unknown biomolecules and organic substances.

Automated summary

The manuscript presents a surface plasmon resonance-based PCF biosensor with high sensing performance and a unique design.