  The interaction between chiral molecules and circularly polarized light is
largely influenced by the local optical chirality density. This interaction
prompts substantial demand of the design of nanophotonic platforms capable of
enhancing such effects across large and accessible volumes. Such a
magnification requires nanostructures that provide strong electric and magnetic
field enhancements while preserving the phase relation of circular light.
Dielectric nanostructures, particularly those able to support resonances, are
ideal candidates for this task due to their capacity for high electric and
magnetic field enhancements. On the other hand, efficient third harmonic
generation calls for strong electric field resonances within dielectric
materials, a feature often boosted by incorporating plasmonic materials into
hybrid systems. In this work, we numerically propose a coupled silicon
disk-gold ring system that can exploit the anapole-induced field confinement to
provide a broadband magnified circular dichroism under realistic conditions,
reaching values up to a 230-fold enhancement. We also demonstrate that this
structure can be employed as an efficient third harmonic generator which, when
integrated with chiral media, enables an 800-fold enhancement in circular
dichroism. Furthermore, we show that pulsed illumination at intensities up to
10 GW/cm2 does not induce temperature increments that could potentially damage
the samples. These findings suggest that this system can be a promising and
versatile approach towards ultrasensitive chiral sensing.
