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Sean Molesky
Princeton University

Abstract:

In this presentation, we will describe how properties of the electromagnetic scattering 𝕋 -operator can be used to set absolute ceilings for any given bounding region and material on a variety of optical processes, ranging from thermal emission, scattering and absorption for propagating waves, to near-field based phenomena like radiative emission from a dipole in the presence of a plasmonic resonance and heat transfer across a nanoscale gap. 

Unifying the two overarching strategies of prior work on electromagnetic limits---modal decomposition (quasi-normal modes, Fourier and multipole expansions) and conservation principles—these 𝕋 -operator bounds are meaningfully applicable to all length scales, show a physically plausible scaling with material quality, and in the large characteristic length limit reproduce familiar ray-optics results. 

We will then discuss the usefulness of 𝕋 -operator bounds in the context of computationally driven "inverse-design" (optimization) algorithms and provide specific examples of structures that nearly reach the performance limit set by our analysis.