Using the vector diffraction theory and the phenomenological model, this paper investigates the second harmonic tion （SHG） of a single centrosymmetric nanosphere excited by focused doughnut beams （DBs） with differ...Using the vector diffraction theory and the phenomenological model, this paper investigates the second harmonic tion （SHG） of a single centrosymmetric nanosphere excited by focused doughnut beams （DBs） with different topological charges. The results show that strong backward SHG （BSHG） appears when the particle is excited by focused DBs with topological charges of ±1. The backward second harmonic radiation can be caused by the depolarized effect of high numerical aperture （NA） objectives due to the strong longitudinal components.展开更多
基金supported by the National High Technology Research and Development Program of China (No.2011AA010205)the National Natural Science Foundation of China (Nos.10704043 and 61171027)+1 种基金the Key Program of the Applied Basic Research of Tianjin (No.10JCZDJC15200)the Specialized Research Fund for the Doctoral Program of Higher Education of China (No.20090031110033)
文摘Using the vector diffraction theory and the phenomenological model, this paper investigates the second harmonic tion （SHG） of a single centrosymmetric nanosphere excited by focused doughnut beams （DBs） with different topological charges. The results show that strong backward SHG （BSHG） appears when the particle is excited by focused DBs with topological charges of ±1. The backward second harmonic radiation can be caused by the depolarized effect of high numerical aperture （NA） objectives due to the strong longitudinal components.
