  Single self-assembled InAs/GaAs quantum dots are promising bright sources of
indistinguishable photons for quantum information science. However, their
distribution in emission wavelength, due to inhomogeneous broadening inherent
to their growth, has limited the ability to create multiple identical sources.
Quantum frequency conversion can overcome this issue, particularly if
implemented using scalable chip-integrated technologies. Here, we report the
first demonstration of quantum frequency conversion of a quantum dot
single-photon source on a silicon nanophotonic chip. Single photons from a
quantum dot in a micropillar cavity are shifted in wavelength with an on-chip
conversion efficiency of approximately 12 %, limited by the linewidth of the
quantum dot photons. The intensity autocorrelation function g(2)(tau) for the
frequency-converted light is antibunched with g(2)(0) = 0.290 +/- 0.030,
compared to the before-conversion value g(2)(0) = 0.080 +/- 0.003. We
demonstrate the suitability of our frequency conversion interface as a resource
for quantum dot sources by characterizing its effectiveness across a wide span
of input wavelengths (840 nm to 980 nm), and its ability to achieve tunable
wavelength shifts difficult to obtain by other approaches.
