arXiv:1702.07590 · Physical Review A
Direct observation of phase-sensitive Hong-Ou-Mandel interference
Petr Marek, Petr Zapletal, Radim Filip, Yosuke Hashimoto, Takeshi Toyama, Jun–ichi Yoshikawa, Kenzo Makino, Akira Furusawa
Abstract
The quality of individual photons and their ability to interfere are traditionally tested by measuring the Hong-Ou-Mandel photon bunching effect. However, this phase-insensitive measurement only tests the particle aspect of the quantum interference, leaving out the phase-sensitive aspects relevant for continuous-variable processing. To overcome these limitations we formulate a witness capable of recognizing both the indistinguishability of the single photons and their quality with regard to their continuous-variable utilization. We exploit the conditional nonclassical squeezing and show that it can reveal both the particle and the wave aspects of the quantum interference in a single set of direct measurements. We experimentally test the witness by applying it to a pair of independent single photons retrieved on demand.