Direct generation of photon triplets using cascaded photon-pair sources

摘要: Non-classical states of light, such as entangled photon pairs and number states, are essential for fundamental tests quantum mechanics optical technologies. The most widespread technique creating these resources is spontaneous parametric down-conversion laser light into pairs. Conservation energy momentum in this process, known phase-matching, gives rise to strong correlations that used produce two-photon entanglement various degrees freedom. It has been a longstanding goal optics realize source can analogous triplets, but the many approaches considered, none technically feasible. Here we report observation triplets generated by cascaded down-conversion. Each triplet originates from single pump photon, therefore will extend over all three photons way not achievable with independently created Our photon-triplet allow experimental interrogation novel correlations, generation tripartite without post-selection heralded suitable linear computing. Two have wavelength matched optimal transmission fibres, three-party communication. Furthermore, our results open interesting regimes non-linear optics, observe pumped photons, an interaction also highly relevant