Energy flows in polychromatic fields

Abstract

This article discusses the mechanisms of forming instant and averaged Poynting vectors in a wave constructed as a superposition of waves with different frequencies. The value of the angular momentum of the field arising as a result of such a superposition is analyzed. It is shown that the averaging time is a determining factor when a polychromatic (formed by waves with different frequencies) optical wave has effects on another physical system. In such a situation, the formation of the transverse component of the Poynting vector, the magnitude of the angular momentum, directly depends on the intermodulation component of the resulting field. The mechanisms of the formation of a time-averaged Poynting vector in polychromatic fields and the influence of coherent wave characteristics on the structure and magnitude of energy flows are considered. The nature of the formation of energy flows depends on the spatial structure of a polychromatic wave. When the field has some symmetry and this requirement is satisfied for all spectral components, the energy fluxes, and the resulting angular momentum of the field can correspond in magnitude to similar characteristics of the coherent field. In other words, the coherent characteristics of the beam do not affect the value of the resulting parameters. Experimental data and computer simulation data are presented.