Tunable Low Loss 1D Surface Plasmons in InAs Nanowires

Due to the ability to manipulate photons at nanoscale, plasmonics has become one of the most important branches in nanophotonics. The prerequisites for the technological application of plasmons include high confining ability (λ₀/λ_p), low damping, and easy tunability. However, plasmons in typical plasmonic materials, i.e., noble metals, cannot satisfy these three requirements simultaneously and cause a disconnection to modern electronics. Here, the indium arsenide (InAs) nanowire is identified as a material that satisfies all the three prerequisites, providing a natural analogy with modern electronics. The dispersion relation of InAs plasmons is determined using the nanoinfrared imaging technique, and show that their associated wavelengths and damping ratio can be tuned by altering the nanowire diameter and dielectric environment. The InAs plasmons possess advantages such as high confining ability, low loss, and ease of fabrication. The observation of InAs plasmons could enable novel plasmonic circuits for future subwavelength applications.