Bayesian optimization of nanophotonic electromagnetic shielding with very high visible transparency

Transparent electromagnetic interference (EMI) shielding is needed in many opto-electronic applications to protect electronic devices from surrounding radiation while allowing for high visible light transmission. However, very high transmission (over 92.5%), high EMI shielding efficiency (over 30 dB) structures have yet to be achieved in the literature. Bayesian optimization is used to optimize different nanophotonic structures for high EMI shielding efficiency (SE) and high visible light transmission ((T) over bar (vis)). Below 90% average visible light transmission, sandwich structures consisting of high index dielectric/silver/high index dielectric films are determined to be optimal, where they are able to achieve 43.1 dB SE and 90.0% (T) over bar (vis). The high index of refraction dielectric layers reduce absorption losses in the silver and can be engineered to provide for antireflection through destructive interference. However, for optimal EMI shielding with (T) over bar (vis) above 90%, the reflection losses at the air/dielectric interfaces need to be further reduced. Optimized double sided nanocone sandwich structures are determined to be best where they can achieve 41.2 dB SE and 90.8% (T) over bar (vis) vis as well as 35.6 dB SE and 95.1% (T) over bar (vis). K-means clustering is utilized to show the performance of characteristic near-Pareto optimal structures. Double sided nanocone structures are shown to exhibit omnidirectional visible transmission with SE = 35.6 dB and over 85% (T) over bar (vis) at incidence angles of 70 degrees. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

This study utilizes Bayesian optimization to find nanophotonic structures with high transmission and EMI shielding efficiency. By adjusting the high index dielectric layers and reducing the reflection losses, better performance can be achieved.