Design of titanium nitride coated PCF-SPR sensor for liquid sensing applications

In this paper, a titanium nitride (TiN) coated highly sensitive PCF-SPR sensor design is proposed and numerically analyzed. Titanium shows the excellent plasmonic properties in the visible and infrared regions and it has low loss and corrosion resistive nature. In this theoretical analysis, we introduce the dependencies of the confinement loss, wavelength sensitivity and amplitude sensitivity to the operating wavelength, thickness of TiN, channel width and refractive index of the measured liquid. For the proposed PCF-SPR sensor design, the high wavelength sensitivity and the refractive index resolution of ∼10,000 nm/RIU and ∼2.0 × 10−5 has been achieved in the refractive index (RI) range of 1.385–1.40, respectively. Even the proposed design has low amplitude sensitivity, but this proposed sensor will be used in detection of RI of chemicals, biochemical analyte with low concentrations, and highly demand in lab-on-a-chip PCF-SPR sensing probe devices.