Fabrication methods for infrared resonant devices.

Abstract

Photonic metastructures operating in the 8-13μm mid-infrared are fast becoming a topic of active research. However, literature describing techniques for their fabrication, which lie on a scale between nanofabrication and microelectromechanical systems technology, is scant. Here, we present detailed fabrication blueprints for achieving robust and repeatable results for devices in this region. Applying a Ge device layer on a ZnS substrate, we fabricate a materially robust transverse-magnetic-polarized wideband reflector with high reflectance in a 2.4μm band. We then regrow a conformal layer on the device, boosting its performance to yield a ∼3 μm 90% reflectance band from 8.1μm to 11.1μm and a band of 98% reflectance spanning 8.7-10.4μm. The generalized methods presented are applicable in most labs with ordinary fabrication resources.