High-performance single-photon generation with commercial-grade optical fiber

Abstract

High-quality quantum sources are of paramount importance for the implementation of quantum technologies. We present here a heralded single-photon source based on commercial-grade polarization-maintaining optical fiber. The heralded photons exhibit a purity of at least 0.84 and an unprecedented heralding efficiency into a single-mode fiber of 85%. The birefringent phase-matching condition of the underlying four-wave mixing process can be controlled mechanically to optimize the wavelength tuning needed for interfacing multiple sources, as is required for large-scale entanglement generation

Temporally uncorrelated photon-pair generation by dual-pump four-wave mixing

“…This also explains the reason for the pairing of G rr with G sr and G ss with G rs in Eq. (13). It is noteworthy that the separability of G rs and G sr is both a necessary and sufficient condition for achieving a separable JTA.…”

“…Especially two cases have been exhaustively studied and demonstrated, for which the JTA is oriented either horizontally (vertically) [18] or at an angle of −45 • [17]. However, both of these configurations exhibit strong abrupt changes in nonlinear interaction at the waveguide endpoints resulting in the well-known sinc-like behavior of the joint spectral amplitude [13,21]. The JTAs of these configurations have recently been carefully analyzed in Ref.…”

“…This purification can be achieved by spectrally filtering out the correlated parts of the joint signal-idler spectrum [13], or by sophisticated methods such as temporal-mode matched filtering [14] or mode-sensitive frequency conversion [15,16]. However, all of these methods share a common downside in that they result in additional photon losses and, consequently, lead to lower * jesbch@fotonik.dtu.dk single-photon rates.…”

Effects of noninstantaneous nonlinear processes on photon-pair generation by spontaneous four-wave mixing

“…This results in small losses, which is ideal for quantum communication purposes. The flexible nature of SFWM can also be used to generate heralded single photons with a high quantummechanical purity [24], without the use of extensive filtering [25][26][27]. This property is crucial for applications in linear optical quantum computing based on photon interference [28], which relies on photon indistinguishability [29,30].…”

Optimization of periodic single-photon sources based on combined multiplexing

“…In the literature there are two typical ways of realizing a heralded single-photon source (HSPS) based on correlated photon pair generation. The two physical phenomena applied for pair generation are spontaneous four-wave mixing (SFWM) in optical fibers [31][32][33][34] and spontaneous parametric down-conversion (SPDC) in bulk crystals [35][36][37][38][39] or waveguides [40][41][42]. These processes can yield highly indistinguishable single photons in an almost ideal single mode with known polarization [33,35,36,41,43].…”