Tailored photon-pair sources based on inner-loop phasematching in fiber-based spontaneous four-wave mixing

摘要

We study the generation of photon pairs by spontaneous four-wave mixing (SFWM) in photonic crystal optical fibers. We show that it is possible to engineer two-photon states with specific spectral entanglement properties suitable for quantum information processing applica- tions. In this work, we concentrate on inner-loop phasematching, for which signal and idler photons can be generated at a small spectral separation from the pump, while sufficiently removed from the pump to ensure the absence of background photons produced by spontaneous Raman scattering. We present specific source designs which permit both symmetric and asymmetric factorable states, which allow herald- ing of pure-state, single-photon wavepackets without the need for spectral post-filtering. Additionally, we present numerical results for the conversion efficiency, where we compare sources based on inner- and outer-loop phasematching.