Supplemental Document Second-harmonic generation divergence—a method for domain size evaluation of 2D materials: supplement J INGWEN D ENG , 1 Z IHAN X U, 2 Z HIHAO Y U, 1,3 AND J UNRONG Z HENG 1,4 1 College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China 2 SixCarbon Technology, Youmagang Industry Park, Shenzhen 518106, China 3 e-mail: zhihaoyu@pku.edu.cn 4 e-mail: junrong@pku.edu.cn This supplement published with The Optical Society on 18 December 2020 by The Authors under the terms of the Creative Commons Attribution 4.0 License in the format provided by the authors and unedited. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Supplement DOI: https://doi.org/10.6084/m9.figshare.13280669 Parent Article DOI: https://doi.org/10.1364/OL.409642