Optical modeling of a GaAs-defect 1D porous silicon photonic crystal for high-sensitivity γ-ray detection

Radiation sensors play a crucial role in diverse fields such as medical diagnostics, environmental monitoring, and nuclear safety. However, many conventional sensors face challenges related to limited sensitivity and operational stability. In this work, we theoretically propose a high-performance γ-ray radiation sensor based on a one-dimensional porous silicon photonic crystal (1D PhC) incorporating a gallium arsenide (GaAs) defect layer and porous silicon layers infiltrated with chalcogenide glass compositions (Se₇₀S_30–xSb_x). The sensing principle is governed by monitoring the shift of the defect mode resonance within the photonic band gap as a function of γ-ray dose (0–500 kGy). Variations in the refractive index of the irradiated chalcogenide glasses were modeled using Bruggeman’s effective medium approximation and incorporated into transfer matrix method (TMM) simulations. The proposed design combines structural simplicity, cost efficiency, and superior sensing metrics, underscoring its strong potential for practical deployment in nuclear radiation detection, medical imaging, and industrial monitoring applications.