Broadband plasmonic indium arsenide photonic antennas†
Abstract
An on-chip integrated mid-infrared Fabry–Perot (F–P) polariton resonator exhibits excellent biosensing, thermal emission, and quantum laser utility potential. However, the narrow optical response range and absence of optoelectronic tunability have hindered the development of a F–P phonon polariton resonator. The discovery of surface plasmons in semiconductor nanowires provides a novel route to F–P polariton resonator devices with a broadband optical response and multi-field tunability. Due to their high electron mobility and crystalline quality, InAs twinning superlattice (TSL) nanowires have become a promising candidate in plasmonic electronics. We systemically studied the F–P plasmonic resonance of individual InAs TSL nanowires with a scattering-type near-field optical microscope. Using a metallic AFM tip to excite surface plasmons, we can observe odd-order and even-order modes of F–P polariton resonance, breaking the symmetric selection rules. Through nano Fourier transform infrared spectroscopy, we found that InAs nanowires’ F–P polariton resonances appear in a broadband frequency range (650–1100 cm−1) and calculated that the corresponding Q factor is 5–10. This semiconductor F–P polariton resonator with inherent electrical tunability will be essential in integrated nanophotonic circuits.