THEORY OF KAPITZA-DIRAC EFFECT

The Kapitza-Dirac effect is the scattering of electrons by a standing wave of very intense light, which can nowadays be realized by using laser beam. A theory is presented, in which no assumptions are necessary as to the strength of the field and to the length of the interaction time. Basic is the assumption that the laser beam should have a gentle cross-sectional profile. It allows one to separate the electron motion into two components: The one parallel to the beam is the motion in the periodic field of light, which generates “adiabatic potential” for the motion transverse to the beam. This picture can be compared to that of hydrogen molecule in which electron motion generates the adiabatic potential for nuclear vibration. In this way, it is shown that the problem can be reduced to that of one-dimensional scattering. The present theory is shown to embrace the predecessor theories of Bartell and of Fedorov. © 1969, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.