Bright Polarized Single-Photon Source Based on a Linear Dipole

Semiconductor quantum dots in cavities are promising single-photon sources. Here, we present a path to deterministic operation, by harnessing the intrinsic linear dipole neutral dot via phonon-assisted excitation. This enables emission of fully polarized single photons, with measured degree polarization up 0.994 $\pm$ 0.007, and high population inversion -- 85\% as resonant We demonstrate source first lens brightness 0.50 $\pm $ 0.01, purity 0.954 0.001 indistinguishability 0.909 0.004.