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Demonstration of a polarization-entangled photon-pair source based on phase-modulated PPLN



Paulina S. Kuo, Varun B. Verma, Sae Woo Nam


We develop and demonstrate a source of polarization-entangled photon pairs using spontaneous parametric down-conversion (SPDC) in domain-engineered, periodically poled lithium niobate (PPLN) at telecom wavelengths. Pumped at 775 nm, this domain-engineered type-II SPDC source produces non-degenerate signal and idler pairs at 1530 nm and 1569 nm. Because of birefringence, the photon pair with horizontally polarized signal and vertically polarized idler has a different phasematching condition than the pair with vertically polarized signal and horizontally polarized idler. Using phase-modulation of the domain structure, we produced a crystal that can simultaneously generate both states in a distributed fashion throughout a single crystal. Performing SPDC using this aperiodically poled crystal, we observed polarization entanglement visibility above 93%. We compare the phase-modulated crystal to other aperiodic structures, including dual-periodically-poled and interlaced biperiodic structures
OSA Continuum


spontaneous parametric downconversion, quasi-phasematching, quantum communications


Kuo, P. , Verma, V. and Nam, S. (2020), Demonstration of a polarization-entangled photon-pair source based on phase-modulated PPLN, OSA Continuum, [online], (Accessed July 14, 2024)


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Created January 29, 2020, Updated May 22, 2020