ULTRA-FAST OPTICAL MODULATION AND ULTRA-SHORT PULSE GENERATION BASED ON TUNABLE GRAPHENE-PLASMONIC HYBRID METASURFACES

摘要

An optical device is disclosed. The optical device includes a silicon substrate, an aluminum oxide layer, an aluminum layer between the silicon substrate and the aluminum oxide layer, and a metasurface nanostructure. The metasurface nanostructure may include a graphene monolayer on the aluminum oxide layer and an electrically conductive nanoantenna array in direct contact with the graphene monolayer, where each nanoantenna in the nanoantenna array may include multiple segments, each segment having one or more parameters selected to achieve simultaneous resonance in the mid-infrared and the near infrared spectral regions when the graphene monolayer is irradiated with a near infrared pump pulse and a continuous mid-infrared probe. The optical device generates mid-infrared pulses via ultrafast modulation of hot carriers in the monolayer graphene.