A CLASSIFICATION OF NEAR FIELD AND ITS RELATIONSHIP WITH STATIC FIELD

For the electromagnetic field generated by local sources, near and far fields are two key concepts which are introduced according to the characteristic wavelength. On the other hand, human understanding of electromagnetic fields has undergone a leap in understanding, from initially discrete static electric/magnetic fields to the complete moving electromagnetic fields described by Maxwell's equations. A finite temporal frequency is a significant characteristic quantity of dynamic field. This paper takes radiation sources of different dimensions as examples to analyze their near-field and far-field generation, distinguish the two mechanisms of near-field generation, and explain the relationship between near-field and static field. Finally, taking Fabry-Perot resonance in dielectric flat plates and surface plasmon resonance of metal particles as examples, the contribution of near-field energy storage in different dimensions and its direct relationship with the significant differences in quality factors of microcavities in different dimensions were revealed.