Application of Second Harmonic Generation in Characterization of 2D Materials
Fangfang Xia, Fakun Wang, Hailong Hu, Xiang Xu, Yang Li, Tianyou Zhai
Abstract
As an important branch of nonlinear optics, second harmonic generation (SHG) is becoming one of the most important means to characterize crystal structure. Among various methods of characterization, because of nondestructive detection, high stability, tunability, ultrafast response, polarization sensitivity, versatility and simplicity, SHG is widely used to characterize the structure of two-dimensional (2D) materials. It provides important information for the physical properties and functional applications of 2D materials, as well as greatly promotes the rapid development of basic research on 2D materials. Here, the current state of the art focuses on the recent research work of SHG in 2D material structure characterization. Firstly, the principle of the second harmonic generation is briefly introduced. Then, the second harmonic generation device with femtosecond laser connected to confocal Raman spectrometer is taken as an example to present the mechanism of SHG. Afterwards, the applications of SHG are demonstrated in the thickness of interlayer stacking of 2D materials, the stacking angle between