Near-field imaging of optical nanocavities in hyperuniform disordered materials

Hyperuniform disordered photonic materials have recently been shown to display large, complete photonic
bandgaps and isotropic optical properties, and are emerging as strong candidates for a plethora of optoelectronic
applications, making them competitive with many of their periodic and quasiperiodic counterparts. In this work, high
quality factor optical cavities in hyperuniform disordered architectures are fabricated through semiconductor slabs
and experimentally addressed by Scanning Near-field Optical Microscopy. The wide range of confined cavity modes
that we detect, arise from carefully designed local modifications of the dielectric structure. Previous works on
hyperuniform disordered photonic systems has previously identified several Anderson localized states spectrally
located at the PBG edges with relatively high quality factors. In this work, by engineering the structural parameters of
the cavity, we achieve an experimental quality factor of order 6000 (higher than the one of the Anderson states) and
we demonstrate that three types of localized modes of different nature coexist within a small area and in a relatively
narrow spectral window of the disordered correlated system. Their compatibility with general boundary constraints,
in contrast with ordered architectures that suffer strict layout constraints imposed by photonic crystal’s axes
orientation, makes optical cavities in disordered hyperuniform patterns a flexible optical insulator platform for planar
optical circuits.