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ItemBi-photon spectral correlation measurements from a silicon nanowire in the quantum and classical regimesJizan, I ; Helt, LG ; Xiong, C ; Collins, MJ ; Choi, D-Y ; Chae, CJ ; Liscidini, M ; Steel, MJ ; Eggleton, BJ ; Clark, AS (NATURE PUBLISHING GROUP, 2015-07-28)The growing requirement for photon pairs with specific spectral correlations in quantum optics experiments has created a demand for fast, high resolution and accurate source characterisation. A promising tool for such characterisation uses classical stimulated processes, in which an additional seed laser stimulates photon generation yielding much higher count rates, as recently demonstrated for a χ(2) integrated source in A. Eckstein et al. Laser Photon. Rev. 8, L76 (2014). In this work we extend these results to χ(3) integrated sources, directly measuring for the first time the relation between spectral correlation measurements via stimulated and spontaneous four wave mixing in an integrated optical waveguide, a silicon nanowire. We directly confirm the speed-up due to higher count rates and demonstrate that this allows additional resolution to be gained when compared to traditional coincidence measurements without any increase in measurement time. As the pump pulse duration can influence the degree of spectral correlation, all of our measurements are taken for two different pump pulse widths. This allows us to confirm that the classical stimulated process correctly captures the degree of spectral correlation regardless of pump pulse duration, and cements its place as an essential characterisation method for the development of future quantum integrated devices.
ItemActive temporal multiplexing of indistinguishable heralded single photonsXiong, C ; Zhang, X ; Liu, Z ; Collins, MJ ; Mahendra, A ; Helt, LG ; Steel, MJ ; Choi, D-Y ; Chae, CJ ; Leong, PHW ; Eggleton, BJ (NATURE PUBLISHING GROUP, 2016-03-01)It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon-generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. Here we demonstrate the multiplexing of photons from four temporal modes solely using fibre-integrated optics and off-the-shelf electronic components. We show a 100% enhancement to the single-photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a fourfold Hong-Ou-Mandel quantum interference with a 91 ± 16% visibility after subtracting multi-photon noise due to high pump power. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies.
ItemNo Preview AvailableCompact and reconfigurable silicon nitride time-bin entanglement circuitXiong, C ; Zhang, X ; Mahendra, A ; He, J ; Choi, D-Y ; Chae, CJ ; Marpaung, D ; Leinse, A ; Heideman, RG ; Hoekman, M ; Roeloffzen, CGH ; Oldenbeuving, RM ; van Dijk, PWL ; Taddei, C ; Leong, PHW ; Eggleton, BJ (OPTICAL SOC AMER, 2015-08-20)