Europhys. Lett.
Volume 65, Number 4, February 2004
Page(s) 485 - 490
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 01 February 2004
Europhys. Lett., 65 (4) , pp. 485-490 (2004)
DOI: 10.1209/epl/i2003-10118-y

Observation of cross-phase shift in hot atoms with quantum coherence

Hong Chang, Yingjie Du, Jingqin Yao, Changde Xie and Hai Wang

The State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-Electronics, Shanxi University - Taiyuan, 030006, PRC

(Received 5 September 2003; accepted 9 December 2003)

We directly measure the cross-phase shift and nonlinear refractive index of a three-level $\Lambda$-type hot atomic coherence system inside an optical ring cavity. The cross-phase nonlinear index of refraction n2 is significantly enhanced and sharply changed when the conditions of atomic two-photon resonance are closed. The cross-phase shift of $\pi$ induced by controlling light on the probe wave has been observed under a relatively low controlling power of 16.2 $\un{mW}$. The system is valuable in developing optical devices for the optical information process.

42.50.Gy - Effects of atomic coherence on propagation, absorption, and amplification of light; electromagnetically induced transparency and absorption.
42.65.Hw - Phase conjugation; photorefractive and Kerr effects.

© EDP Sciences 2004