Single quantum dot-in-a-rod embedded in a photonic nanowire waveguide for telecom band emission

Abstract

Bright emission from non-classical light sources is a key requirement for their practical use in quantum optics. In this Letter, we report on an alternative approach to realize high-brightness nanowire emitters in the telecom band. We discuss the growth and optical properties of a single InAs0.68P0.32 quantum dot in an InAs0.50P0.50 quantum rod, all embedded in an InP nanowire waveguide. Modifying the bandgap energy of the matrix surrounding the quantum dot by inserting it into an InAs0.50P0.50 quantum rod, instead of InP, reduces the barrier height for carriers in the dot. As a result, light emission at λ = 1310 nm is reached from an InAs0.68P0.32 dot grown with the same deposition conditions as that used for λ = 950 nm emission in the conventional structure. We demonstrate that the dot-in-a-rod (DROD) configuration increases (up to fivefold) the emission rate of the emitters at 1310–1550 nm as compared to those grown with the higher dot aspect ratio required when not using the DROD structure. Carrier generation localized to the dot (quasi-resonant scheme) is achieved by optically pumping the rod below the InP bandgap.