Direct generation of polarization-entangled photon pairs in a poled fiber

Zhu, Eric, Tang, Zhiyuan, Qian, Li, Helt, Lukas, Liscidini, Marco, Sipe, J.E., Corbari, Costantino, Canagasabey, Albert, Ibsen, Morten and Kazansky, Peter (2012) Direct generation of polarization-entangled photon pairs in a poled fiber. Physical Review Letters, 108 (21), 213902-[5pp]. (doi:10.1103/PhysRevLett.108.213902).

Abstract

We experimentally demonstrate the direct generation of polarization-entangled photon pairs in an optical fiber at room temperature by exploiting type-II phase-matched spontaneous parametric down-conversion. A second-order nonlinearity is artificially induced in the 17-cm-long weakly birefringent step-index fiber through the process of thermal poling, and quasi-phase-matching allows for the generation of entangled photons in the 1.5-micron telecom band when the fiber is pumped at 775 nm. A greater-than 80:1 coincidence-to-accidental ratio is achieved, limited mainly by multiphoton pair generation. Without the need to subtract accidentals or to compensate for walk-off, the raw two-photon interference visibility is found to be better than 95%, and violation of Bell’s inequality is observed by more than 18 standard deviations. This makes for a truly alignment-free, plug-and-play source of polarization-entangled photon pairs.

This record has no associated files available for download.

Contributors

Download statistics