Phase-stable source of polarization-entangled photons in a linear double-pass configuration

Author(s): F. Steinlechner, S. Ramelow, M. Jofre, T. Jennewein, J. P. Torres, M. W. Mitchell, V. Pruneri, M. Gilaberte

Journal: Optics Express

Volume: 21

Page(s): 11943-11951

Year: 2013

DOI Number: 10.1364/OE.21.011943

Link: Link to publication


We demonstrate a compact, robust, and highly efficient source of polarization-entangled photons, based on linear bi-directional down-conversion in a novel ‘folded sandwich’ configuration. Bi-directionally pumping a single periodically poled KTiOPO4 (ppKTP) crystal with a 405-nm laser diode, we generate entangled photon pairs at the non-degenerate wavelengths 784 nm (signal) and 839 nm (idler), and achieve an unprecedented detection rate of 11.8 kcps for 10.4 μW of pump power (1.1 million pairs / mW), in a 2.9-nm bandwidth, while maintaining a very high two-photon entanglement quality, with a Bell-state fidelity of 99.3 ± 0.3%.


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