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

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 InA s 0.68 P 0.32 quantum dot in an InA s 0.50 P 0.50 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 InA s 0.50 P 0.50 quantum rod, instead of InP, reduces the barrier height for carriers in the dot. As a result, light emission at lambda =1310nm is reached from an InA s 0.68 P 0.32 dot grown with the same deposition conditions as that used for lambda =950nm 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 1310-1550nm 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.