Analyzing Near-Field Intensity Distribution in Subwavelength Gratings through Cylindrical Wave Decomposition

Abstract: The investigation into the scattering of plane waves by a periodic array of parallel cylinders utilizes the method of cylindrical wave decomposition, thereby reducing the problem complexity to a series of linear algebraic equations. This methodology proves particularly efficacious when the diameter of cylinders is significantly less than the wavelength of incident wave, resulting in a rapid diminution of the solution coefficients as a function of azimuth numbers. Such a reductionist approach facilitates the computation of scattered radiation intensity in near field. Subsequent cross-validation with numerical results corroborates the theoretical findings, showcasing a qualitative concordance between the two. This study underscores the efficacy of cylindrical wave decomposition in simplifying and accurately modeling wave scattering phenomena in structured media.