We present the moments formalism theory to study the deflection of the slow signal light in the cold atomic media,which is under the condition of the Gaussian control laser and electromagnetically induced transparency.Deflection,the interesting phenomenon on quantum coherence,is testified by analytic and numerical methods.Results show that,as the signal light propagating in the medium,there would be an observable deflection before the general diffraction.Influences of the coupling intensity on deflection phenomenon and the beam waist of the signal light in the medium are also investigated.
We study the spatial behavior of a deflected beam in a coherent A-type three-level atomic medium with an inhomogeneous control laser.When the Rabi coupling by the control laser is in a Gaussian profile,the spatialdependent refraction index of the atomic medium will result in a beam splitting as well as the deflection of the slow probe light under electromagnetically induced transparency.In terms of the phase difference between the two splitting beams and the position of the splitting,the possible interpretation of the splitting is given in theory.
Lensless ghost diffraction with partially coherent sources is investigated theoretically and numerically.Based on the classical optical coherent theory and the Gauss–Shell model of the partially coherent sources,we derive an analytical imaging formula of lensless ghost diffraction(LGD).Using this formula,we can see the effects of the transverse size and coherence of the sources,the detector size and defocusing length on the quality of LGD.Numerical results are presented to show that for different detector sizes and defocusing lengths,high quality LGD can be realized by using sources with appropriate transverse sizes and coherent widths.These findings can be used to choose the optimal parameters in the design of a realistic LGD system.
