Fig. 1. (a) Schematic diagram of SRR-based meta-molecule; (b) absorption spectrum of the meta-molecule consisting of two SRRs with a twist angle φ = 90°; (c) distributions of magnetic field component H_z on the surface of the SRRs at wavelengths corresponding to two absorption peaks wl1 and wl2. (a)由两个金属SRR上下堆叠组成的超构分子结构示意图; (b)上下两个SRR相对开口朝向夹角为φ = 90°时超构分子的吸收谱; (c)与吸收谱中两个吸收峰对应的波长wl1和wl2处SRR表面的磁场垂直分量H_z分布图

Fig. 2. (a) Absorption spectrum and (b) the SHG intensity with the relative angle of the two layers changing. The black dash line represents the line connecting the left and right peaks of each line.双层相对角度改变时, (a)吸收谱和(b) SHG强度的变化, 黑色划线代表每条线左右峰值的连线

Fig. 3. When the relative angle of the two layers changes from 30° to 150°, (a) SHG intensity, (b) amplitude ratio of SHG in the y and x directions and (c) the phase difference of SHG in the y and x directions as a function of wavelength; when the relative angle of the two layers is 60°, (d) SHG intensity, (e) amplitude ratio of SHG in the y and x directions and (f) the phase difference of SHG in the y and x directions as a function of wavelength. The shaded area indicates a wavelength region where the SHG efficiency is relatively large. 双层相对角度为30°—150°时的远场SHG强度 (a)、SHG辐射的y和x分量的振幅比E_y/E_x (b)和相位差δ(c)随着波长的变化; 双层相对角度为60°时的远场SHG强度 (d)、SHG辐射的y和x分量的振幅比E_y/E_x (e)和相位差δ (f)随着波长的变化; 其中阴影区域表示SHG效率较大的一段波长区域

Fig. 4. Polarization of the far-field SHG changes when the relative angle of the two layers is 60°, and the the fundamental wave of different wavelengths is incident.双层相对角度为60°、不同波长的基波入射时, 远场SHG偏振态的变化

Fig. 5. When the incidentwavelengthis 1500 nm, the polarization of the far-field SHG changes with the relative angle of the two layers基波波长为1500 nm入射时, 不同相对角度的结构的远场SHG偏振态的变化