Abstract
•Dispersion diagram analysis of photonic crystal waveguide for RI sensing.•Improvement in transmission as well as sensitivity.•Designed photonic crystal waveguide shows a high sensitivity of 450nm/RIU.•FDTD analysis of the designed structure to analyze functionality.
Photonic crystal waveguide, to be used as a highly sensitive platform for refractive index based sensing applications, has been analyzed in this paper. The sensing performance is estimated by using dispersion diagram through using plane wave expansion simulations. The dispersion diagram is used to obtain transmittance and cut-off wavelengths for analyzing the sensor characteristics. It has been proposed that the photonic crystal waveguide with ring-type line defect provides a better perspective for sensing applications as compared to the conventional photonic crystal waveguide. An optimized ring-type photonic crystal waveguide structure with a defect filling factor of 50% shows a refractive index sensitivity of 450nm/RIU having almost double the output signal strength compared to hole-type line defect waveguide with the same filling factor.