In recent years, significant interest has emerged in the inverse design1 of
artificial layered heterostructures for photonic applications2. Specifically, the unique optical properties of nearzero permittivity (ENZ) metamaterials have enabled the exploration of novel physical effects and mechanisms. In this presentation, I will focus into how thin film photonics
harnesses the potential of Fano resonances3-5. By layering metaldielectric thin films, we can create a distinct type of optical coating that exhibits photonic Fano resonance, referred to as a Fano-resonant optical coating (FROC). We extend the concept of coupled mechanical oscillators to thin-film nanocavities, shedding light on semi-transparent FROCs that
can both transmit and reflect the same color, akin to a beam splitter filter. This remarkable property is beyond the capabilities of conventional optical coatings.

REFERENCES
[1] Lininger, A., Hinczewski, M., & Strangi, G. “General Inverse Design of Layered Thin-Film Materials with Convolutional Neural Networks”. ACS PHOTONICS, 8(12), 3641-3650 (2021)
[2] K. V. Sreekanth, Y. Alapan, M. ElKabbash, U. A. Gurkan, E. Ilker, M. Hinczevski, A. De Luca and G. Strangi NATURE MATERIALS 15, 4 4609 (2016)
[3] ElKabbash, M.; Letsou, T.; Jalil, S. A; Hoffman; Lininger, A. R; Fann, C.; Hinczewski, M.; and Strangi, G.; “Fano-resonant ultrathin film optical coatings” NATURE NANOTECHNOLOGY, 16, 4, 440-446 (2021)
[4] ElKabbash, Mohamed; Hoffman, Nathaniel; Lininger, Andrew R; Jalil, Sohail A; Letsou, Theodore; Hinczewski, Michael; Strangi, Giuseppe; Guo, Chunlei; “Fano resonant optical coatings platform for full gamut and high purity structural colors” NATURE COMMUNICATIONS, 14, 1 3960 (2023).
[5] Sreekanth K. V., Mohamed ElKabbash, Vincenzo Caligiuri, Ranjan Singh, Antonio De Luca, and Giuseppe Strangi Book: “New Directions in Thin Film Nanophotonics” - Progress in Optical Science and Photonics ISBN: 978-981-13-8890-3. ISBN: 978-981-13-8891-0. NATURE -SPRINGER Singapore (2019)