X. Liu, M. F. Xue and J. Chen
On-chip integrated mid-infrared Fabry-Perot (F-P) polaritons resonance has 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 the F-P phonon polariton resonator. The discovery of surface plasmons in semiconductor nanowires provides a novel route for F-P polaritons resonator devices with a broadband optical response and multi-field tunability. Due to its high electron mobility and crystalline quality, InAs twinning superlattice (TSL) nanowire has 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 the metallic AFM tip to excite surface plasmons, we can observe odd-order and even-order modes of the F-P polaritons resonance, breaking the symmetric selection rules. Through nano Fourier transform infrared spectroscopy, we found that InAs nanowires' F-P polaritons 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 polaritons resonator with inherent electrical tunability will be essential in integrated nanophotonic circuits.