Mode Confinement in Photonic Quasi-Crystal Point-Defect Cavities for Particle Accelerators

TL;DR

This study investigates how aperiodic photonic structures with point defects can better confine modes for particle accelerator cavities, using simulations and measurements to compare with periodic structures.

Contribution

It demonstrates that aperiodic photonic quasi-crystal cavities offer improved mode confinement over periodic structures for particle accelerator applications.

Findings

Aperiodic geometries show superior confinement properties.

Reduced-size structures benefit from aperiodic arrangements.

Experimental microwave measurements confirm simulation results.

Abstract

In this Letter, we present a study of the confinement properties of point-defect resonators in finite-size photonic-bandgap structures composed of aperiodic arrangements of dielectric rods, with special emphasis on their use for the design of cavities for particle accelerators. Specifically, for representative geometries, we study the properties of the fundamental mode (as a function of the filling fraction, structure size, and losses) via 2-D and 3-D full-wave numerical simulations, as well as microwave measurements at room temperature. Results indicate that, for reduced-size structures, aperiodic geometries exhibit superior confinement properties by comparison with periodic ones.