Fig. 2
From: Scalable ion–photon quantum interface based on integrated diffractive mirrors
Single photon generation protocol. a Pulse sequence for σ + and σ − lasers and detection gating. b 174Yb+ level diagram showing π photons result in optical pumping to a dark state. c Experimental set-up of the second order correlation measurement g (2). Ion fluorescence is analyzed with a linear polariser (P) to filter out σ photons, leaving only π photons to be divided by a 50/50 non-polarizing beamsplitter (NPBS) between two photomultiplier tube detectors (DET1, DET2). Arrival time statistics are accumulated by a digital interval analyzer. d Measured coincidence counts and second-order correlation g (2). Peak spacing corresponds to 3.25 μs experimental repetition period
