  In this paper, we present a comparative study of the tuning efficiency and
sensitivity of guided resonances (GRs) in photonic crystal (PC) holed slabs
based on periodic and aperiodically-ordered unit cells, aimed at assessing the
applicability of these important technology platforms to ultra-compact optical
sensors and active devices. In particular, with specific reference to
square-lattice periodic PCs and aperiodically-ordered Ammann-Beenker photonic
quasi-crystals, we study the effects of the hole radius, slab thickness, and
refractive index on the GR sensitivity and tunability with respect to variation
in the hole refractive index. Finally, we carry out a theoretical and numerical
analysis in order to correlate the GR shift with the field distribution of the
unperturbed (air holes) structures. Our results indicate that the spatial
arrangement of the holes may strongly influence the tuning and sensitivity
efficiency, and may provide new degrees of freedom and tools for the design and
optimization of novel photonic devices for both sensing and telecommunication
applications.
