This study aims to design and evaluate a photonic crystal (PC) sensor for high-intensity light detection, leveraging the nonlinear Kerr effect. The sensor structure incorporates zinc oxide (ZnO) as a defect layer embedded within alternating multilayers of silicon dioxide (SiO2) and silicon (Si).
The reflection spectrum and defect-mode behavior of the proposed sensor were analyzed using the transfer matrix method, with theoretical results validated through the finite element method. Sensor optimization was achieved by fine-tuning individual layer thicknesses. Additionally, the impact of fabrication-induced geometric deviations (±5% variation in thickness) was investigated to evaluate the device’s robustness. The distribution of the electric field was also simulated.
The resonance dip of the defect mode was observed to shift toward shorter wavelengths with increasing light intensity, resulting from a decrease in the refractive index of ZnO due to the Kerr effect. The resonance exhibited a sharp peak and minimal spectral broadening. The sensor demonstrated an average sensitivity of 203.9 nm/(MW/cm2). Moreover, the structure retained reliable optical performance despite fabrication tolerances up to ±5%.
This work introduces a novel, high-performance PC sensor that exploits Kerr-induced refractive index modulation in ZnO. The integration of nonlinear optical behavior, precise multilayer engineering and robustness against fabrication errors positions the sensor as a promising solution for high-intensity optical sensing applications.
