Manipulating the Color and Shape of Single Photons generated by Quantum Nanophotonic Devices

Single photon sources created through scalable planar fabrication may play an important role in future quantum information technology. Ideally, these sources will be bright, have strongly suppressed multi-photon emission, and produce identical (indistinguishable) photons in an on-demand fashion. Furthermore, one would like to control the wavelength and temporal profile of the single photon wavepackets, to detect them in an optimally efficient manner, interface them with quantum memories, or overcome fabrication-induced inhomogeneity. In this talk, I will outline our laboratory’s efforts at generating and manipulating single photon states produced by nanophotonic devices. Single InAs/GaAs quantum dots embedded in grating microcavities, waveguides, and microdisk resonators generate bright single photon emission into a single mode free-space or fiber optic channel. We then manipulate the color of the generated photons through quantum frequency conversion in periodically-poled lithium niobate waveguides, demonstrating telecom- to-visible conversion and enabling two-photon interference of spectrally separated states of a single quantum dot. We also show that synchronized amplitude modulation is a valuable resource in temporally filtering single quantum dot emission, as it can suppress multi-photon events, improve the source indistinguishability by selecting only the coherent portion of the wavepackets, and provide a straightforward route to manipulating the shape of single photons. Finally, I will discuss efforts to use nonlinear optics in silicon-based platforms for generation and frequency conversion of single photons.