有序金纳米棒阵列的超分辨成像

显微成像技术受限于光学成像系统的衍射极限,无法分辨亚波长尺度的结构。通过饱和散射抑制成像技术已经实现了单个纳米颗粒的超分辨成像,但是涉及到纳米颗粒集合,需要考虑纳米颗粒间的耦合作用。利用超越衍射极限的双光束方法,可以在有序金纳米棒阵列上实现远场超分辨光学成像。本文设计了纳米棒长径比为2的5×5金纳米棒阵列,通过矢量光场理论和热扩散理论计算了金纳米棒阵列在连续波激光下的热分布,并模拟了双光束激光即脉冲激发光和连续波抑制光下的散射成像。仿真结果显示,连续波激光能够有效抑制金纳米棒阵列对脉冲激光的散射,双光束方法实现了80 nm横向特征尺寸的超分辨成像。

Super-resolution imaging for ordered gold nanorod arrays

Microscopic techniques cannot resolve subwavelength scale structures due to the diffraction limit of optical imaging systems. Super-resolution imaging of single nanoparticles has been achieved by saturation scattering suppression imaging techniques, but when it comes to ensembles of nanoparticles, the coupling between nanoparticles needs to be considered. Far-field super-resolution optical imaging can be achieved on ordered gold nanorod arrays using a two-beam method beyond the diffraction limit. In this paper, a 5×5 gold nanorod array with an aspect ratio of 2 is designed, the thermal distribution of the gold nanorod array under continuous-wave laser is calculated by the vector light field theory and thermal diffusion theory, and the scattering imaging under dual-beam laser, i.e., pulsed excitation light and continuous-wave suppression light, is simulated. The simulation results show that the continuous-wave laser can effectively suppress the pulsed laser scattering of gold nanorod arrays, and the two-beam approach achieves super-resolution imaging with 80 nm resolution.