Polarization Entanglement by Time-Reversed Hong-Ou-Mandel Interference

Funding

We thank Thomas Scheidl and Johannes Handsteiner for helpful conversations and comments on the initial draft of the manuscript as well as Valerio Pruneri for providing ppKTP crystals. Y.C. thanks Lijun Chen for support. Financial support from the Austrian Research Promotion Agency (FFG) Projects-Agentur fur Luft-und Raumfahrt (FFG-ALR Contracts No. 6238191 and No. 866025), the European Space Agency (ESA Contract No. 4000112591/14/NL/US), as well as the Austrian Academy of Sciences is gratefully acknowledged. Y.C. acknowledges personal funding from Major Program of National Natural Science Foundation of China (No. 11690030 and No. 11690032), National Key Research and Development Program of China (2017YFA0303700), the National Natural Science Foundation of China (No. 61771236), and from a Scholarship from the China Scholarship Council (CSC).