Guided Mode Excitation-Based All-Dielectric High Contrast Grating Sensor for Visible Region

In this work, we report a guided mode resonance (GMR)-based all-dielectric high contrast grating (ADHCG) sensor for the excitation of dual modes, under Transverse Magnetic (TM) polarization for detection in the visible range. This sensor chip consists of a thick high index dielectric grating deposited directly on the substrate. The excitation of the guided modes due to the periodic modulations of the grating gives rise to sharp resonant peaks in the reflection response. The resonant position of both peaks is dependent on the refractive index (RI) modulation, making RI-based biological, chemical, and environmental sensing a suitable application of this sensor. The sensitivity (S), full width at half maxima (FWHM), the figure of merit (FOM), and quality factor (Q) for the optimal configuration of this sensor are 101.2 nm/RIU, 0.338 nm, 299.29 RIU−1, and 1413.692 for the first mode and 102.76 nm/RIU, 0.121 nm, 849.27 RIU−1, and 4264.94 for the second mode, respectively.