We show that the quantum interference between down-converted photon pairs and photons from coherent laser light can produce a maximally path entangled $N$ -photon output component with a fidelity greater than 90% for arbitrarily high photon numbers. A simple beam splitter operation can thus transform the two-photon coherence of down-converted light into an almost optimal $N$ -photon coherence.We show that the quantum interference between down-converted photon pairs and photons from coherent laser light can produce a maximally path entangled $N$-photon output component with a fidelity greater than 90% for arbitrarily high photon numbers. A simple beam splitter operation can thus transform the two-photon coherence of down-converted light into an almost optimal $N$-photon coherence.

arXiv:0705.0047Physical Review ASep 28, 2007105 citations

Quantum Interference from Independent Photons

Rainer Kaltenbaek, B. Blauensteiner, Markus Aspelmeyer +1 more

Bulletin of the American Physical SocietyMar 24, 20050 citations

Two-photon quantum interference with independent sources

Rainer Kaltenbaek, B. Blauensteiner, Markus Aspelmeyer +2 more

Jan 1, 20050 citations

Quantum diffraction and interference of spatially correlated photon pairs generated by spontaneous parametric down-conversion

Ryōsuke Shimizu, Keiichi Edamatsu, Tadashi Itoh

We demonstrate one- and two-photon diffraction and interference experiments utilizing parametric down-converted photon pairs (biphotons) and a transmission grating. With two-photon detection, the biphoton exhibits a diffraction-interference pattern equivalent to that of an effective single particle that is associated with half the wavelength of the constituent photons. With one-photon detection, however, no diffraction-interference pattern is observed. We show that these phenomena originate from the spatial quantum correlation between the down-converted photons.We demonstrate one- and two-photon diffraction and interference experiments utilizing parametric down-converted photon pairs (biphotons) and a transmission grating. With two-photon detection, the biphoton exhibits a diffraction-interference pattern equivalent to that of an effective single particle that is associated with half the wavelength of the constituent photons. With one-photon detection, however, no diffraction-interference pattern is observed. We show that these phenomena originate from the spatial quantum correlation between the down-converted photons.

arXiv:quant-ph/0210142Physical Review AApr 25, 200342 citations

One- and Two-Photon Interference

Paul G. Kwiat

Compendium of Quantum PhysicsJan 1, 20091 citation

Short interference fringe and high event rate of two-photon interference using up-converted photon pairs

Atsushi Syouji, Ryōsuke Shimizu, Shigehiro Nagano +2 more

Abstract We demonstrate a hybrid approach to detecting a short fringe period of two-photon interference with high brightness, by combining spontaneous parametric down-conversion (SPDC) and up-conversion techniques. Photon pairs were generated at the wavelength of 1550 nm via SPDC, and converted to 516.7 nm through up-conversion process with the pump light 775 nm in efficiency ∼90%. The two-photon interference of the up-converted photon pairs exhibited a fringe period of 258.3 nm with high event rate (∼2000 counts s−1), which was 6 times shorter than the original wavelength, demonstrating that the energy-time correlation of the photon pairs was preserved. The technique simultaneously provides short fringe period beyond the classical limit and high brightness of the photon pairs.Abstract We demonstrate a hybrid approach to detecting a short fringe period of two-photon interference with high brightness, by combining spontaneous parametric down-conversion (SPDC) and up-conversion techniques. Photon pairs were generated at the wavelength of 1550 nm via SPDC, and converted to 516.7 nm through up-conversion process with the pump light 775 nm in efficiency ∼90%. The two-photon interference of the up-converted photon pairs exhibited a fringe period of 258.3 nm with high event rate (∼2000 counts s−1), which was 6 times shorter than the original wavelength, demonstrating that the energy-time correlation of the photon pairs was preserved. The technique simultaneously provides short fringe period beyond the classical limit and high brightness of the photon pairs.

Japanese Journal of Applied PhysicsFeb 1, 20230 citations

We show that the quantum interference between down-converted photon pairs and photons from coherent laser light can produce a maximally path entangled

N

-photon output component with a fidelity greater than 90% for arbitrarily high photon numbers. A simple beam splitter operation can thus transform the two-photon coherence of down-converted light into an almost optimal

N

-photon coherence.