For sensing, infrared imaging, and spectroscopy, working in the mid-infrared is extremely desirable.  While there's been a huge amount of work on MIR sources and detectors, the work on integrated optical platforms at these wavelengths is comparatively immature compared to integrated optics at telecommunications wavelengths. Dr. Hochberg's team at UW built and measured the first integrated optical waveguides and resonators in silicon-on-sapphire for the mid-infrared; SOS is an intriguing platform for integrated optics in the mid-infrared, since it's transparent to long wavelengths and offers both low waveguide loss and

high confinement.