  Solid state quantum emitters have shown strong potential for applications in
quantum information, but spectral inhomogeneity of these emitters poses a
significant challenge. We address this issue in a cavity-quantum dot system by
demonstrating cavity-stimulated Raman spin flip emission. This process avoids
populating the excited state of the emitter and generates a photon that is
Raman shifted from the laser and enhanced by the cavity. The emission is
spectrally narrow and tunable over a range of at least 125 GHz, which is two
orders of magnitude greater than the natural linewidth. We obtain the regime in
which the Raman emission is spin-dependent, which couples the photon to a
long-lived electron spin qubit. This process can enable an efficient, tunable
source of indistinguishable photons and deterministic entanglement of distant
spin qubits in a photonic crystal quantum network.
