All-dielectric optical antennas offer unique advantages in fabrication of highly reproducible Raman probes and light management at the meso- and nano-scale. Hot-spot engineering is a key step for enhancing the local field and promoting light channelling from far- to near-field. However, unlike the case of plasmonic antennas, hot-spot design and implementation in all-dielectric systems is still largely underdeveloped. Inspired by building-up principles that govern absorption, trapping and scattering of visible light in a variety of biological structures and guided by finite element optical simulations, here we explored the potential of self-similar dielectric optical antennas in light coupling with Mie-type modes. The systems investigated were based on the combination of primary and secondary antennas, made of micron- and nano-sized TiO2 nanoshells. Different types of configurations, including randomly and …