Mid Infrared Surface Relief Photonic Devices using High-Index Contrast Amorphous Germanium Sub-wavelength Structures

摘要

Strongly index-modulated sub-wavelength grating structures of amorphous-germanium on low index substrates can realize simple, single-layer spectral filters and nonlinear frequency conversion surfaces in the mid-infrared range. This paper reviews some of our work on the electromagnetic design and experiments on amorphous-germanium based surface-relief photonic devices.