  We report the slow-light enhanced spin-resolved in-plane emission from a
single quantum dot (QD) in a photonic crystal waveguide (PCW). The slow light
dispersions in PCWs are designed to match the emission wavelengths of single
QDs. The resonance between two spin states emitted from a single QD and a slow
light mode of a waveguide is investigated under a magnetic field with Faraday
configuration. Two spin states of a single QD experience different degrees of
enhancement as their emission wavelengths are shifted by combining diamagnetic
and Zeeman effects with an optical excitation power control. A circular
polarization degree up to 0.81 is achieved by changing the off-resonant
excitation power. Strongly polarized photon emission enhanced by a slow light
mode shows great potential to attain controllable spin-resolved photon sources
for integrated optical quantum networks on chip.
