Indistinguishable and efficient single photons from a quantum dot in a planar nanobeam waveguide

Planar photonic technology provides a highly promising route of creating an on-chip and on-demand source of single photons, which can be scaled into photonic circuitry. While self-assembled quantum dots have been proven to be excellent coherent single-photon emitters in many microscale structures, in nanoscale devices the photon coherence can be compromised due to the nearby surfaces. Here, the authors achieve 94% indistinguishability of photons emitted from a nanoscale photonic waveguide under p-shell excitation.