Focusing properties of a photonic crystal slab with multiple mechanisms in addition to negative refraction.
A brief review of imaging by a photonic crystal (PC) slab with negative refraction is given. The focusing properties of the PC with multiple mechanisms in addition to negative refraction are studied by the finite-difference time-domain method. In addition to the effect of negative refraction, there are multiple mechanisms that are all attributed to the PC focusing properties, including Bragg diffraction, excitation of the surface mode, and self-collimation. The resulting field pattern is the total result of these factors. Bragg diffraction occurs in the high-frequency domain and mainly influences the quality of focusing in the optical axis direction. The excitation of the surface mode improves the resolution of focusing. Self-collimation makes the focusing position deviate from Snell's law.
Fang
Yun-tuan
YT
Department of Physics, Zhenjiang Watercraft College, Zhenjiang, China 212003. fang_yt1965@sina.com
Zhou
Jun
J