All-epitaxial, laterally structured plasmonic materials

Optoelectronic devices in the mid-infrared have attracted significant interest due to numerous potential applications in communications and sensing. Molecular beam epitaxial (MBE) growth of highly doped InAs has emerged as a promising “designer metal” platform for the plas- monic enhancement of mid-infrared devices. However, while typical plasmonic materials can be patterned to engineer strong localized reso- nances, the lack of lateral control in conventional MBE growth makes it challenging to create similar structures compatible with monolithically grown plasmonic InAs. To this end, we report the growth of highly doped InAs plasmonic ridges for the localized resonant enhancement of mid-IR emitters and absorbers. Furthermore, we demonstrate a method for regaining a planar surface above plasmonic cor- rugations, creating a pathway to epitaxially integrate these structures into active devices that leverage conventional growth and fabrication techniques.