Publication

Abstract : Photonic structures with dimensions comparable to the operating wavelength have been studied widely of late, especially the performance of micro-resonators supporting Whispering Gallery modes (WGMs). Coupled assemblies of two or more resonators have also proved of great interest in the optical regime where they have been shown to offer further control over pertinent properties such as Q-factor, modal volume and emission or sensing properties. These coupled resonator structures have been called photonic molecules (PMs) due to the similarity between their mode structure and the electron orbital structure found in the chemical molecules that they resemble in structural geometry. Microwave scale models of optical micro-resonators, excited at microwave frequencies, demonstrate similar resonant features to the corresponding optical structures and so provide an extremely useful experimental tool with which to explore the properties of photonic molecules [1, 2]. Dielectric materials used to fabricate the microwave models are easily available and comparatively inexpensive. Further, the dimensions being in the larger centimetre-scale, the structures can be conveniently fabricated with high precision. In this presentation we describe the results of such microwave-scale experiments to determine the resonant and directional emission properties of (i) single resonators with various geometries, including notched microdisk resonators [3], and (ii) an assortment of geometrical arrangements of similar and dissimilar (size-mismatched) microresonators.Comparisons are made with the predictions of numerical simulations based on an integral equation analysis.