High Q Chalcogenide Photonic Crystal Nanobeam Cavities

We report high quality (Q) photonic crystal (PhC) nanobeam cavities in the chalcogenide glass Ge
₂₈
Sb
₁₂
Se
₆₀
near 1550 nm wavelength. By optimizing the structure of the PhC cavity, an ultra-high Q factor as large as
$5\times 10^{6}$
is predicted by simulation, and up to
$1.2\times 10^{4}$
is measured in the experiment. Such high-Q cavities in this strongly nonlinear material create an attractive platform for compact, ultrafast all-optical switches.