Near-field imaging of optical nano-cavities in Hyperuniform disordered materials

TL;DR

This paper demonstrates the fabrication and experimental characterization of high-Q optical cavities in hyperuniform disordered photonic materials, revealing multiple localized modes with potential for flexible optoelectronic applications.

Contribution

It reports the creation of high-quality factor optical cavities in hyperuniform disordered structures and identifies multiple localized modes within a small spectral window, surpassing previous Anderson state quality factors.

Findings

Achieved an experimental quality factor of around 6000.

Detected multiple localized modes of different nature.

Cavities show compatibility with boundary constraints, enabling flexible optical insulator platforms.

Abstract

Hyperuniform disordered photonic materials have recently been shown to display large, complete photonic band gaps 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 have 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 crystals' axes orientation, makes optical cavities in disordered hyperuniform patterns a flexible optical insulator platform for planar optical circuits.