Quantum optics of multi-level lasers

S. G. Lipson, H. Lipson, David Stefan Tannhauser

Liyong Wang, Yifu Zhu

We propose a scheme of interaction-free bidirectional multi-channel all-optical switching in a multi-level coupling system consisting of four-level atoms confined in a cavity and coupled by a free-space control laser. A signal laser field is coupled into the cavity and excites two separate transitions of atoms simultaneously under the collective strong coupling condition. The transmission and reflection of signal fields form bidirectional output channels. A free-space control laser induces destructive quantum interference in the multi-level excitation of an atom-cavity system, which can be used to switch on/off the output signal lights of transmission/reflection channels. There is no direct coupling of control light and signal light through the cavity-confined atoms because the output of signal light is nearly totally suppressed to the opposite direction when control light is present. The proposed all-optical switching scheme can be realized with high switching efficiency, broad bandwidth, and weak light intensity. It may be useful for future devices of optical routing, optical communications, and various quantum logic elements.

Yi-Xin Chen, SHANGGUAN WANGZUO, JI DA-REN +1 more

In this paper we investigate the quantum jump in a multi-level atom and construct a formal solution to the optical Block equation describing the interaction system of the multi-level atom with incident resonant laser. It is proved that pure state analysis theory is no longer applicable to a multi-level atom system, so a mixed one is developed, concluding that the resetting density of a multi-level atom should be described by mixed state analysis theory. We also discuss the continuous quantum measurement along with quantum jumping in a multi-level atom.

Lorenzo M. Narducci, Eduardo Jaime Quel, Jorge R. Tredicce

Yi Xia

Abstract In this paper we investigate the quantum jump in a multi level atom and construct a formal solution to the optical Block equation describing the interaction system of the multi level atom with incident resonant laser.It is proved that pure state analysis theory is no longer applicable to a multi level atom system,so a mixed one is developed,concluding that the resetting density of a multi level atom should be described by mixed state analysis theory.We also discuss the continuous quantum measurement along with quantum jumping in a multi level atom.

Zhizhan Xu, Shengwu Xie, Shi-Yao Zhu +1 more