  Metasurfaces with bound states in the continuum (BICs) have proven to be a
powerful platform for drastically enhancing light-matter interactions,
improving biosensing, and precisely manipulating near- and far-fields. However,
engineering metasurfaces to provide an on-demand spectral and angular position
for a BIC remains a prime challenge. A conventional solution involves a fine
adjustment of geometrical parameters, requiring multiple time-consuming
calculations. In this work, to circumvent such tedious processes, we develop a
physics-inspired, inverse design method on all-dielectric metasurfaces for an
on-demand spectral and angular position of a BIC. Our suggested method predicts
the core-shell particles that constitute the unit cell of the metasurface,
while considering practical limitations on geometry and available materials.
Our method is based on a smart combination of a semi-analytical solution, for
predicting the required dipolar Mie coefficients of the meta-atom, and a
machine learning algorithm, for finding a practical design of the meta-atom
that provides these Mie coefficients. Although our approach is exemplified in
designing a metasurface sustaining a BIC, it can, also, be applied to many more
objective functions. With that, we pave the way toward a general framework for
the inverse design of metasurfaces in specific and nanophotonic structures in
general.
