n-type Ge/Si antennas for THz sensing

Ge-on-Si plasmonics holds the promise for compact and low-cost solutions in manipulation of THz radiation. We discuss here plasmonic properties doped Ge bow-tie antennas made with a low-point cost CMOS mainstream technology. These display resonances between 500 700 GHz, probed by time domain spectroscopy. show surface functionalization thin layer α-lipoic acid that red-shifts antenna about 20 GHz. Moreover, we protected silicon nitride cap exhibit comparable red-shift when covered biolayer. This suggests electromagnetic fields at hotspot extend well beyond layer, enabling possibility to use an improved protection material conjunction microfluidics.