By using a weak measurement technique, we investigated the interplay between the angular and lateral Goos-Hänchen shift of a focused He-Ne laser beam for incidence near the critical angle. We verified that this interplay dramatically affect the composite Goos-Hänchen shift of the propagated beam. The experimental results confirm theoretical predictions that recently appeared in the literature.

Abstract. We show in which conditions optical gaussian beams, propagating throughout an homogeneous dielectric right angle prism, present an asymmetric Goos-Hänchen (GH) effect. This asymmetric behavior is seen for incidence at critical angles and happens in the propagation direction of the outgoing beam. The asymmetric GH effect can be also seen as an amplification of the standard GH shift. Due to the fact that it only depends on the ratio between the wavelength and the minimal waist size of the incoming gaussian beam, it can be also used to determine one of these parameters. Multiple peaks interference is an additional phenomenon seen in the presence of such asymmetric effects.

Abstract. We use the stationary phase method to determine the path of optical beams which propagate through a dielectric block. In the presence of partial internal reflection, we recover the geometrical result obtained by using the Snell law. For total internal reflection, the stationary phase method overreaches the Snell law predicting the Goos-Hänchen shift.

•• Physical Review A 90, 033844-11 (2014) Physical Review A 90, 033844-11 (2014A detailed analysis of the propagation of laser gaussian beams at critical angles shows in which conditions it is possible to maximize the breaking of symmetry in the angular distribution and for which values of the laser wavelength and beam waist is possible to find an analytic formula for angular deviations of the Snell law. For propagation throughout N dielectric blocks and for a full breaking of symmetry, overcoming the well known problem of the infinity at critical angle, a closed expression for the Goos-Hänchen shift is obtained. The multiple peaks phenomenon clearly represents an additional evidence of the breaking of symmetry in the angular distribution of optical beams. Finally, laser wavelength and beam waist conditions to produce focal effects in the outgoing beam are also briefly discussed.

We use a coupled-wave theory analysis to describe an atomic phase grating based on the giant Kerr nonlinearity of an atomic medium under electromagnetically induced transparency. An analytical expression is found for the diffraction efficiency of the grating. Efficiencies greater than 70% are predicted for incidence at the Bragg angle.