Enhanced continuous-variable entanglement by a self-phase-locked type-II optical parameter oscillator with feedback loops

We consider a three-level cascade laser with a self-phase-locked type-II nondegenerate optical parameter oscillator via a homodyne-mediate quantum feedback. Applying the pertinent master equation, we investigate the squeezing, entanglement properties and the mean photon number produced by our system. It is found that highly squeezed and macroscopic entangled light with high intensity can be generated.