Research on Optical Chirality of Asymmetric Nanorings
Circularly polarized light(CPL)and chiral molecules exhibit enation-selectivity,which can be used to achieve optical chiral resolution.It has been shown that metal-dielectric nanoparticles with a high refractive index can enhance this enantioselectivity,but the enantioselectivity of different spatial struc-tures will produce a nearly zero spatial average enhancement.However,a feasible solution for this problem is to improve the circular dichroism of nanostructures and to increase the optical chirality density C and Kuhn's dissymmetry factor g.a two-dimensional gold nano chiral ring(CR)surface was designed using FDTD.This monomer structure can exhibit strong circular dichroism(CD).A great enhancement of CD and large spans of wavelength bands can be achieved by altering three geometric parameters of the CR,in-cluding the inner radius r,ring width w,and ring height h.At the near-infrared wavelength segment,the peak value of the circular dichroism reached 0.25 and-0.26,respectively.
chiralitycircular dichroismfinite difference time domain method
万方数据
维普
