通过 CARS、SHG 和 TPEF 对多孔碳材料的非线性光学特性进行表征。

Nonlinear optical characterization of porous carbon materials by CARS, SHG and TPEF.

机构信息

School of Physics, Dalian University of Technology, Dalian 116024, China.

Center for Green Innovation, School of Mathematics and Physics, Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, University of Science and Technology Beijing, Beijing 100083, China.

出版信息

Spectrochim Acta A Mol Biomol Spectrosc. 2019 May 5;214:58-66. doi: 10.1016/j.saa.2019.02.010. Epub 2019 Feb 6.

DOI:10.1016/j.saa.2019.02.010

PMID:30769152

Abstract

The Coherent anti-Stokes Raman scattering (CARS) microscopy is employed to characterize porous carbon materials. The slices of two dimensional (2D) CARS images are obtained, using Z-scan technology. Furthermore, the three dimensional (3D) image of CARS is reconstructed with the Z-scanned 2D CARS images. The visualizations of rotation for 3D CARS are also shown. The 2D and 3D CARS images with rotations can clearly characterize the structures and properties of porous carbon materials, including the surface and inner parts. Nonlinear optical second harmonic generation demonstrates the inversion symmetry breaking of porous carbon materials, which is not centrosymmetric material. The two-photon excitation fluorescence image reveals that porous carbon material is of weak auto-fluorescence. The clearly observed signal of two photon-excitation fluorescence provides direct evidence that photon momentum transfer to the electron system occurs. Experimental results demonstrate that the nonlinear optical microscopy is a great optical analysis method for the study of porous carbon materials, and can be potentially used for the optical characterization on the materials at micro-nano-scale.

摘要

相干反斯托克斯拉曼散射（CARS）显微镜用于表征多孔碳材料。使用 Z 扫描技术获得二维（2D）CARS 图像的切片。此外，利用 Z 扫描的 2D CARS 图像重建了 CARS 的三维（3D）图像。还显示了 3D CARS 的旋转可视化。具有旋转的 2D 和 3D CARS 图像可以清楚地表征多孔碳材料的结构和特性，包括表面和内部。非线性光学二次谐波产生表明多孔碳材料的反转对称性被打破，这是非中心对称材料。双光子激发荧光图像显示多孔碳材料的自发荧光很弱。双光子激发荧光的明显观测信号提供了光子动量传递到电子系统的直接证据。实验结果表明，非线性光学显微镜是研究多孔碳材料的一种很好的光学分析方法，并且可潜在地用于微纳尺度下材料的光学特性研究。