Design and numerical investigation of silicon carbide (SiC) waveguide and micro ring resonator as a photonic sensor

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This work presents a SiC based photonic integrated sensing platform investigated through numerical simulation that operates at a wavelength of 1.55 µm. The study begins with a detailed analysis of rectangular SiC waveguides employing SiO 2 and Al 2 O 3 as cladding materials. Using finite element based electromagnetic simulations, the confined power factor (PCF), loss and effective mode index are evaluated for transverse electric (TE) and transverse magnetic (TM) modes as functions of wavelength, core height and core width. The results show that SiO 2 cladding provides greater power confinement of 97.05% at TE mode and 96.51% at TM mode, lower propagation loss of -0.971 dB/cm for TE and -0.934 dB/cm for TM mode and effective mode index of 2.348 and 2.377 at TE and TM situations, whereas Al 2 O 3 cladding results in higher effective mode index values of 2.372 at TE and 2.392 at TM mode, loss of -0.881 dB/cm at TE and -0.911 dB/cm at TM mode and a lower PCF of 95.86% at TE mode and 94.76% at TM mode. On the basis of the optimized waveguide parameters, a SiC micro ring resonator is designed on a SiO 2 substrate and analyzed as a refractive index sensor. Changes in the surrounding refractive index result in measurable resonance wavelength shifts at both the output and drop ports. The sensing performance is evaluated for gas molecules, normal and cancerous cells, and selected viruses and bacteria. The device demonstrates clear resonance shifts corresponding to refractive index variations with calculated sensitivity, quality factor, and figure of merit values confirming its capability for label free sensing of multiple analyte types.