Abstract
Theoretical study on entangled photon generation from a quantum dot (QD) embedded in microcavity is
briefly reviewed within a strong coupling regime. In this system, entangled photon pairs can be
generated through the cascade photon emission via dressed states in the cavity quantum electrodynamics
(CQED). Excitation levels of a QD are modeled by a V-type three-level system and four-level system
including a biexciton. In contrast to the entangled-photon generation until now, all four Bell states can
be generated from an identical cavity system by simply selecting applied-field polarizations and
frequencies as characteristic features of the CQED. The CQED effects play a crucial role in providing a
high degree of entanglement: (i) spectral fi ltering can be used to extract entangled photons due to the
vacuum Rabi splitting and (ii) non-entangled co-polarized photons are strongly suppressed due to the
photon blockade effect.
