Mode-Matched Resonant Excitation of a Nanowire Quantum Dot in a Nanophotonic Waveguide

Nanowire-based quantum dots as sources of single photons are promising candidates for the implementation of quantum photonic technologies. Achieving coherent control of these sources is essential for generating indistinguishable single photons─a key requirement for quantum interference. However, coherent excitation of nanowire quantum dots via resonant pumping has remained a long-standing challenge due to high laser suppression requirements. Here we establish a reliable technique to implement resonant excitation of a quantum dot in a tapered single-mode nanowire waveguide by complementing polarization-rejection with mode-matching to minimize the amount of backscattered laser. We demonstrate low multiphoton emission [<i>g</i>_<i>X</i>⁽²⁾(0) = 0.019] and multiple Rabi oscillations under pulsed resonant excitation. We also report on two-photon indistinguishability under resonant excitation, achieving an interference visibility of 41%. This is a significant improvement over incoherent excitation and represents an important step in the development of a scalable approach for producing coherent single-photon sources.