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Victor Leong

Publications and source records attributed to Victor Leong.

21 records · Page 2Linked to original sources

Time-resolved Scattering of a Single Photon by a Single Atom

Scattering of light by matter has been studied extensively in the past. Yet, the most fundamental process, the scattering of a single photon by a single atom, is largely unexplored [1-3]. One prominent prediction of quantum optics is the deterministic absorption of a traveling photon by a single atom, provided the photon waveform matches spatially and temporally the time-reversed version of a spontaneously emitted photon [4-12]. Here, we experimentally address this prediction and investigate the influence of the temporal profile of the photon on the scattering dynamics using a single trapped atom and heralded single photons. In a time-resolved measurement of the atomic excitation we find a 56(11)% increase of the peak excitation by photons with an exponentially rising profile compared to a decaying one. This result demonstrates that tailoring the envelope of single photons enables precise control of the photon-atom interaction.

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Hong-Ou-Mandel interference between triggered and heralded single photons from separate atomic systems

We present Hong-Ou-Mandel interference of single photons generated via two different physical processes by two independent atomic systems: scattering by a single atom, and parametric generation via four-wave mixing in a cloud of cold atoms. Without any spectral filtering, we observe a visibility of V=62$\pm$4%. After correcting for accidental coincidences, we obtain V=93$\pm$6%. The observed interference demonstrates the compatibility of the two sources, forming the basis for an efficient quantum interface between different physical systems.

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Diffraction-limited Fabry-Perot Cavity in the Near Concentric Regime

Nearly concentric optical cavities can be used to prepare optical fields with a very small mode volume. We implement an anaclastic design of a such a cavity that significantly simplifies mode matching to the fundamental cavity mode. The cavity is shown to have diffraction-limited performance for a mode volume of $\approx10^4λ^3$. This is in sharp contrast with the behavior of cavities with plano-concave mirrors, where aberrations significantly increase the losses in the fundamental mode. We estimate the related cavity QED parameters and show that the proposed cavity design allows for strong coupling without a need for high finesse or small physical cavity volume.

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