摘要We employ a sample of cold 87Rb atoms in a magneto-optical trap to study the impulse responses and spatial characters of backward conjugate waves in a four-wave mixing process. We measure the slow and superluminal group velocities of backward conjugate waves, and find the sensitive variation of the spatial mode of backward waves with the probe-pump detuning and the dependence of the reflectance on the magnetic field, while the trapping magnetic field exists.
Abstract：We employ a sample of cold 87Rb atoms in a magneto-optical trap to study the impulse responses and spatial characters of backward conjugate waves in a four-wave mixing process. We measure the slow and superluminal group velocities of backward conjugate waves, and find the sensitive variation of the spatial mode of backward waves with the probe-pump detuning and the dependence of the reflectance on the magnetic field, while the trapping magnetic field exists.
[1] Fisher R A 1983 Optical Phase Conjugation (New York:Academic) [2] Zeldovich B Ya, Popovichev V I, Ragulskii V V andFaizullov F S 1972 Sov. Phys. JETP 15 109 [3] Liao P F and Bloom D M 1978 Opt. Lett. 3 4 [4] Wu Q, Xu J J, Rupp R, Zhang X Z, Lou C B and Bugaychuk S2006 Chin. Phys. Lett. 23 2101 [5] Rahn L A and Brown M S 1994 Opt. Lett. 19 1249 [6] Yeung J Au, Fekete D, Pepper D M, Yariv A and Jain R K1979 Opt. Lett. 4 42 [7] Do B, Cha J, Elliott D S and Smith S J 1998 Phys.Rev. A 58 3089 [8] Bloom D M, Liao P F and Economou N P 1978 Opt. Lett. 2 58 [9] Camacho R M, Vudyasetu P K and Howell J C 2009 NaturePhotonics 3 103 [10] Fan J, Dogarin A and Wang L J 2005 Opt. Lett. 30 1530 [11] Du S, Wen J, Rubin M H and Yin G Y 2007 Phys. Rev.Lett. 98 053601 [12] Lin J, Rubiera A I and Zhu Y 1995 Phys. Rev. A 52 4882 [13] Tabosa J W R, Vianna S S and de Oliverira F A M 1997 Phys. Rev. A 55 2968 [14] Tabosa J W R, Chen G, Hu Z, Lee R B and Kimble H J 1991 Phys. Rev. Lett. 66 3245 [15] Brillouin L 1960 Wave Propagation and GroupVelocity (New York: Academic) [16] Du S, Belthangady C, Kolchin P, Yin G Y and Harris S E2008 Opt. Lett. 33 2149 [17] Lezama A, Barreiro S, Lipsich A and Akulshin A M 1999 Phys. Rev. A 61 013801
2010, Vol. 27 
