Quantum dot single-photon emission coupled into single-mode fibers with 3D printed micro-objectives
Abstract
User-friendly single-photon sources with high photon-extraction efficiency are crucial building blocks for photonic quantum applications. For many of these applications, such as long-distance quantum key distribution, the use of single-mode optical fibers is mandatory, which leads to stringent requirements regarding the device design and fabrication. We report on the on-chip integration of a quantum dot microlens with a 3D-printed micro-objective in combination with a single-mode on-chip fiber coupler. The practical quantum device is realized by deterministic fabrication of the QD-microlens via in-situ electron-beam lithography and 3D two-photon laser writing of the on-chip micro-objective and fiber-holder. The QD with microlens is an efficient single-photon source, whose emission is collimated by the on-chip micro-objective. A second polymer microlens is located at the end facet of the single-mode fiber and ensures that the collimated light is efficiently coupled into the fiber core. For this purpose, the fiber is placed in the on-chip fiber chuck, which is precisely aligned to the QD-microlens thanks to the sub-m processing accuracy of high-resolution two-photon direct laser writing. This way, we obtain a fully integrated high-quality quantum device with broadband photon extraction efficiency, a single-mode fiber-coupling efficiency of 26%, a single-photon flux of 1.5 MHz at single-mode fibre output and a multi-photon probability of 13 % under pulsed optical excitation. In addition, the stable design of the developed fiber-coupled quantum device makes it highly attractive for integration into user-friendly plug-and-play quantum applications.
Cite
@article{arxiv.2005.11198,
title = {Quantum dot single-photon emission coupled into single-mode fibers with 3D printed micro-objectives},
author = {Lucas Bremer and Ksenia Weber and Sarah Fischbach and Simon Thiele and Marco Schmidt and Arsenty Kakganskiy and Sven Rodt and Alois Herkommer and Marc Sartison and Simone Luca Portalupi and Peter Michler and Harald Giessen and Stephan Reitzenstein},
journal= {arXiv preprint arXiv:2005.11198},
year = {2020}
}