Multimode Time-Delay Interferometer for Free-Space Quantum Communication
Clinton Cahall, Nurul T. Islam, Daniel J. Gauthier, Jungsang Kim · Physical Review Applied · 2020
Optical communication via free-space channels is attractive for establishing long-range secure quantum networks, but is often hindered by deleterious effects on the transverse spatial mode profile of the beam, caused by propagation through the atmosphere. Additionally, interferometric measurement at the receiver becomes much more difficult with multimode profiles. This study presents a compact time-delay interferometer with high stability and interference visibility for single- and multimode spatial profiles. The results of this study are important for the future of quantum communication networks as well as a wide range of techniques for classical and quantum optical measurement.