Three-dimensional quantum photonic elements based on single nitrogen vacancy-centres in laser-written

To fully integrate quantum optical technology, active quantum systems must be combined with resonantmicrostructuresandopticalinterconnectsharvestingandroutingphotonsinthreediemsnsions(3D)ononechip.Wefabricatesuchcombinedstructuresforthefirsttimebyusingtwo-photonlaserlithographyandaphotoresist containing nanodiamonds including nitrogen vacancy-centers. As an example for possiblefunctionality, single-photon generation, collection, and transport is successfully accomplished. The singlephotonsareefficientlycollectedviaresonatorsandroutedin3Dthroughwaveguides,allononeopticalchip.Ourone-stepfabricationschemeiseasytoimplement,scalableandflexible.Thus,othercomplexassembliesof 3D quantum optical structures are feasible as well.