Resonance absorption of electromagnetic waves in an inhomogeneous medium without a cavity

В. И. Бородулин

Андрій Сіжук, Konstantin E. Dorfman, C. H. Raymond Ooi

The spatial inhomogeneity of absorption coefficient of the space between mirrors, filled by an optically active gas, is analyzed in quantum optical terms. It was theoretically shown, that the quantization of electromagnetic field in a cavity (optical resonator) can reveal the spatial inhomogeneity of absorption or re-emission ability of the optically active medium. It appears from the analytical calculations, the inhomogeneity is caused by the Doppler frequency shifts (including recoil effects) during the atom-photon collisions and the non-zero initial frequency width of the scanning signal. The proposed analytical representation of the absorption coefficient through the additive quantum optical terms gives deeper insight into intrinsic processes in the interacting with light matter.

Zhenfei Luo, Zhizhan Xu

Kazuki Koshino, Akira Shimizu

We consider the spontaneous emission (SE) of radiation by an atom in a one-dimensional cavity which consists of two medium regions and a vacuum region between them. The medium regions are composed of a bulk dielectric material which has a continuous absorption spectrum. We quantize the electromagnetic field as well as the polarization fields of the material, and polaritons composed of infinite number of fields are obtained. Using the polariton solutions, we then study the SE for an atom in such an absorptive and inhomogeneous cavity. The SE rate is shown to depend strongly on the position of the atom, the length l of the vacuum region, and the complex refractive index \ensuremath{\eta}+i\ensuremath{\kappa}. It is found in particular that the position dependence of the SE rate disappears for some particular values of l, in either of the vacuum or medium region. We also find that unlike the three-dimensional case the SE rate in a homogeneous cavity depends on both \ensuremath{\eta} and \ensuremath{\kappa}. \textcopyright{} 1996 The American Physical Society.

Haitao Zhou, Shaona Che, Pengcheng Zuo +2 more

The cavity transmission spectrum is experimentally investigated in Λ-type three-level atoms coupled to a standing-wave cavity system. It is shown that the dark-state polariton peak is not generated at resonance but rather at off-resonance. The theoretical analysis reveals that the absence of an on-resonance dark-state polariton peak is mainly caused by the strong absorption of the intracavity medium to the probe cavity mode counterpropagating with the coupling field due to the Doppler shift in the hot atoms. Moreover, the optimal frequency position of the cavity mode for an efficient dark-state polariton peak is also demonstrated.

V. S. Pekar