Phase shift caused by microwave field based on light storage

Abstract

We have theoretically investigated the phase shift of a probe field for a four-level atomic system interacting successively with two fields tuned near an EIT resonance of an atom, a microwave field, and a coupling field. It has been found that the phase of retrieved signal has been shifted due to the cross-phase modulation when the stored spin wave was disturbed by a microwave. Because of the low relaxation rates of the ground hyperfine state, our proposed technique can impart a large phase rotation onto the probe field with low absorption of retrieved field and very low intensity of the microwave field.

Keywords:

• atom–light interaction
• cross-phase modulation
• light storage
• electromagnetically induced transparency

Acknowledgements

This work is supported by the Knowledge Innovation Program (KIP) of the Chinese Academy of Sciences with No. KGCX3-SYW-405 and the National Fundamental Research Program of China with Nos. 2005CB724507, 2006CB921202.