Fiber-pigtailing quantum-dot cavity-enhanced light emitting diodes

We report on a process for the fiber-coupling of electrically driven cavity-enhanced quantum dot light emitting devices. The developed technique allows for the direct and permanent coupling of p-i-n-doped quantum dot micropillar cavities to single-mode optical fibers. The coupling process, fully carried out at room temperature, involves a spatial scanning technique, where the fiber facet is positioned relative to a device with a diameter of 2 mu m using the fiber-coupled electroluminescence of the cavity emission as a feedback parameter. Subsequent gluing and UV curing enable a rigid and permanent coupling between micropillar and fiber core. Comparing our experimental results with finite element method simulations indicates a cavity-to-fiber mode-coupling efficiency of similar to 46%. Furthermore, we demonstrate pulsed current injection at a repetition rate exceeding 200MHz as well as low-temperature operation down to 77K of the fiber-coupled micropillar device. The technique presented in this work is an important step in the quest for efficient and practical quantum light sources for applications in quantum information. Published under an exclusive license by AIP Publishing.

Automated summary

This study reports a technique for fiber-coupling of electrically driven cavity-enhanced quantum dot light emitting devices, achieving efficient quantum light sources for applications in quantum information. The developed process allows direct and permanent coupling of quantum dot micropillar cavities to single-mode optical fibers, with a mode-coupling efficiency of around 46%. Additionally, pulsed current injection at a repetition rate exceeding 200MHz and low-temperature operation down to 77K of the fiber-coupled micropillar device were demonstrated.