TY  - GEN
A1  - Henkel, Carsten
A1  - Courtois, Jean-Yves
A1  - Aspect, Alain
T1  - Atomic diffraction by a thin phase grating
N2  - We present a semiclassical perturbation method for the description of atomic diffraction by a weakly modulated potential. It proceeds in a way similar to the treatment of light diffraction by a thin phase grating, and consists in calculating the atomic wavefunction by means of action integrals along the classical trajectories of the atoms in the absence of the modulated part of the potential. The capabilities and the validity condition of the method are illustrated on the well-known case of atomic diffraction by a Gaussian standing wave. We prove that in this situation the perturbation method is equivalent to the Raman-Nath approximation, and we point out that the usually-considered Raman-Nath validity condition can lead to inaccuracies in the evaluation of the phases of the diffraction amplitudes. The method is also applied to the case of an evanescent wave reflection grating, and an analytical expression for the diffraction pattern at any incidence angle is obtained for the first time. Finally, the application of the method to other situations is briefly discussed.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 101 
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42269
ER  - 
TY  - GEN
A1  - Henkel, Carsten
A1  - Courtois, Jean-Yves
A1  - Kaiser, Robin
A1  - Westbrook, C.
A1  - Aspect, Alain
T1  - Phase shifts of atomic de Broglie waves at an evanescent wave mirror
N2  - A detailed theoretical investigation of the reflection of an atomic de Broglie wave at an evanescent wave mirror is presented. The classical and the semiclassical descriptions of the reflection process are reviewed, and a full wave-mechanical approach based on the analytical soution of the corresponding Schrödinger equation is presented. The phase shift at reflection is calculated exactly and interpreted in terms of instantaneous reflection of the atom at an effective mirror. Besides the semiclassical regime of reflection describable by the WKB method, a pure quantum regime of reflection is identified in the limit where the incident de Broglie wavelength is large compared to the evanescent wave decay length.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 103 
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42289
ER  - 
TY  - JOUR
A1  - Westbrook, N.
A1  - Henkel, Carsten
A1  - Westbrook, C. I.
A1  - Landragin, A.
A1  - Labeyrie, G.
A1  - Cognet, L.
A1  - Savalli, V.
A1  - Horvath, G.
A1  - Aspect, Alain
A1  - Moelmer, Klaus
A1  - Courtois, J.-Y.
A1  - Phillips, W. D.
A1  - Kaiser, Rolf
A1  - Bagnato, V.
T1  - New physics with evanescent wave atomic mirrors : the van der Waals force and atomic diffraction
N2  - After a brief introduction to the field of atom optics and to atomic mirrors, we present experimental results obtained in our group during the last two years while studying the reflection of rubidium atoms by an evanescent wave. These involve the first measurement of the van der Waals force between an atom in its ground state and a dielectric wall, as well as the demonstration of a reflection grating for atoms at normal incidence. We also consider the influence of quantum reflection and tunnelling phenomena. Further studies using the atomic mirror as a probe of the van der Waals interaction, and of very small surface roughness are briefly discussed.
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Henkel, Carsten
A1  - Wallis, H.
A1  - Westbrook, N.
A1  - Aspect, Alain
A1  - Sengstock, K.
A1  - Ertmer, W.
T1  - Theory of atomic diffraction from evanescent waves
N2  - We review recent theoretical models and experiments dealing with the diffraction of neutral atoms by a reflection grating, formed by a standing evanescent wave. We analyze diffraction mechanisms proposed for confront the theory with experiment.
Y1  - 1999
ER  -