Study novel design of broadband edge filter as a smart window for energy saving

This study presents a new optimized broadband optical short wave pass (OSWP) edge filter designed for smart window applications to increase energy efficiency. The proposed filter has a dielectric structure with double layer composed of alternative high and low refractive index materials, which is designed to transmit the visible light and reflect the near-infrared (NIR) radiation. To achieve this functionality, we used the transfer matrix method (TMM) with the needle synthesis technique through the Essential Macleod software, which allows the accurate optimization of the thickness of the layer for maximum spectral control. The simulation results show that the filter maintains high visible light transmittance (>96%), while effectively blocks infrared wavelengths (750-1500 nm), with different performance as a function of the angle of incidence. The passive modulation properties of the filter provide seasonally adaptive thermal regulation, making it a viable solution for energy-saving smart window technologies. The results are relevant with the real world's solar incident angles in Riyadh, Saudi Arabia.