Cavity linewidth narrowing with dark-state polaritons**Project supported by the National Natural Science Foundation of China (Grants Nos. 11204080, 11274112, 91321101, and 61275215) and the Fundamental Research Fund for the Central Universities of China (Grants No. WM1313003).

Abstract

We present a quantum-theoretical treatment of cavity linewidth narrowing with intracavity electromagnetically induced transparency (EIT). By means of intracavity EIT, the photons in the cavity are in the form of cavity polaritons: bright-state polariton and dark-state polariton. Strong coupling of the bright-state polariton to the excited state induces an effect known as vacuum Rabi splitting, whereas the dark-state polariton decoupled from the excited state induces a narrow cavity transmission window. Our analysis would provide a quantum theory of linewidth narrowing with a quantum field pulse.