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arl92 edited this page Nov 20, 2020 · 3 revisions

Welcome to the FROC (Fano Resonant Ultra-Thin Film Optical Coatings) Homepage!

Background

Optical coatings are found in a wide variety of optical instruments. Their applications span many branches of science and technology including lasers, astronomy, displays and lighting, photovoltaics, to name a few. Although a century old, there are only a handful of optical coating types. Here, we introduce a new type of optical coatings that exhibit the photonic Fano resonance effect.

What is a FROC?

FROC is a Fano Resonant Ultrathin-Film Optical Coating, a new type of thin-film optical coating based on photonic Fano resonance. We extend the coupled mechanical oscillators framework to thin film nano-cavities to model FROCs. Using FROCs with ultrathin thickness, we experimentally obtain narrowband reflection akin to low-index-contrast dielectric Bragg mirrors and demonstrate control over the reflection iridescence. Semi-transparent FROCs exhibit a unique property of transmitting and reflecting the same color as a beam splitter filter (a beam splitting color filter); a property that cannot be realized via conventional optical coatings.

Applications to Photovoltaics

We show that a nanoscale FROCs can spectrally and spatially separate the thermal and photovoltaic bands of the solar spectrum as a possible solution to the dispatchability problem in solar-cell technologies while realizing higher power generation (up to 50%) and lower photovoltaic cell temperatures (~ 30 ) that can lead to a six-fold increase in the photovoltaic cell lifetime.