Engineering of Quantum Emitter Properties

A single quantum emitter coupled to an optical waveguide is a promising platform for realizing highly efficient non-linear light-matter interactions. By employing a tapered geometry, both the injection and collection efficiency of light to such systems can be enhanced to near-unity. In this study, we investigate light injection into tapered InP nanowires with embedded InAsP quantum dots (QDs) using k-space extinction microscopy. Numerical simulations estimate that > 80% extinction of reflected light under ideal mode matching conditions corresponds to ≈ 90% in-coupling of incident light into the fundamental optical mode of the nanowire. We experimentally verify this claim by utilizing the QD emission under two-photon resonant excitation as a sensor to quantify the proportion of light coupled into the fundamental mode of the nanowire waveguide.