Demonstration of mid-infrared waveguide photonic crystal cavities

TL;DR

This paper demonstrates the first mid-infrared waveguide photonic crystal cavities fabricated from chalcogenide glass, achieving a quality factor of around 2,000 at 5.2 micrometers.

Contribution

It introduces the first mid-infrared waveguide photonic crystal cavities and details their fabrication and characterization.

Findings

Achieved a quality factor of ~2,000 at 5.2 μm

Fabricated using photolithography and focused ion beam milling

Operates near the critical coupling regime

Abstract

We have demonstrated what we believe to be the first waveguide photonic crystal cavity operating in the mid-infrared. The devices were fabricated from Ge23Sb7S70 chalcogenide glass on CaF2 substrates by combing photolithographic patterning and focus ion beam milling. The waveguide-coupled cavities were characterized using a fiber end fire coupling method at 5.2 {\mu}m wavelength, and a loaded quality factor of ~ 2,000 was measured near the critical coupling regime.