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.
We show how quantum entangled biphoton states can be used to realize ghost scattering, a nonlocal scheme to obtain scattering information of an unknown object through the correlation measurement of the scattering photons in two different optical paths. We present a framework to describe the biphoton ghost scattering process from the T-matrix formula of the scattering theory. We find the scattering information of a test object can be retrieved from either the test arm or the reference arm. By adjusting the biphoton states, the ghost scattering patterns may be varied from the scattering pattern of the object in the test arm to the object in the reference arm.
