<title>Self-reconstruction ability of wave field</title>

Abstract

ABSTRACT The periodical self-reconstruction of the transverse spatial intensity profile of the coherent monochromatic wavefield and the spatio-temporal self-reconstruction of the wave packet are analysed. We present both the theoretical description of the effect and the approximate model related to the experimental realization. Applications of the self-reconstruction resulting in the beam self-guiding and the self-imaging are also discussed and demonstrated innumerical simulations.Keywords : nondiffracting beam , self-imaging , Talbot effect 1. INTRODUCTION Propagation of the wave field and transformation of its intensity profile belong to the classical problems of physics,in particular of optics. Free propagation of wave field is accompanied by diffraction resulting in the spread of itstransverse intensity profile. In the last decade, an attention has been focused on the special class of fields calledpropagation-invariant fields. They can appear in two different forms of beams known as the nondiffracting beams'and the beams exhibiting the self-imaging effect.5'6 The term nondiffracting beam denotes exact solutions of thellelmholtz equation whose transverse intensity profile remains unchanged in free propagation. The term self-imaging