The accompanying zip file contains data for paper Grating-induced slow-light enhancement of second-harmonic generation in periodically poled crystals (PRA). DOI: https://link.aps.org/doi/10.1103/PhysRevA.105.013517 Datatset can be found at https://doi.org/10.5258/SOTON/D2096 The authors acknowledge funding through the UK National Quantum Technologies Programme (EPSRC Grants No. EP/T001062/1 and No. EP/M024539/1) and an EPSRC DTP Ph.D. studentship. We also acknowledge the use of the IRIDIS High Performance Computing Facility, and associated support services at the University of Southampton, in the completion of this work. All data is stored in open source HTF5 files (.h5) with a corresponding python script which extracts the data into numpy data types for analysis. The data files correspond to the figures in the paper as follows: Figure 2 -------- data file: data_789279.h5 Figure 3 -------- data file: data_637338.h5 Figure 4 (a) ------------ data file: data_637338.h5 Figure 4 (b) ------------ data file: data_814685.h5 Figure 4 (c) ------------ data file: data_637338.h5 data file: data_814685.h5 Figure 5 (a) ------------ date file: data_692062.h5 Figure 5 (b) ------------ date file: data_692062.h5 Figure 6 -------- date file: data_813392.h5 date file: data_322535.h5 Figure 7 (a) ------------ date file: data_002986.h5 Figure 7 (b) ------------ date file: data_002986.h5 Figure 7 (c) ------------ date file: data_552620.h5 Figure 8 (a) ------------ date file: data_211239.h5 Figure 8 (b) ------------ date file: data__211239.h5 Figure 9 (a) ------------ date file: data_303554.h5 Figure 9 (b) ------------ date file: data_303554.h5