This repository contains all data, analysis, and figure files associated with the manuscript "Self-Induced Superradiant Masing", which investigates a hybrid system consisting of a microwave cavity coupled to an ensemble of nitrogen-vacancy centers in diamond. The data are provided as a single archive file (data_repository__Self_Induced_SR_Masing.zip) together with a README.txt that describes the folder structure and contents. The archive includes: \figures – final figures and figure components used in the paper. \measurement_data – experimental data files (.mat) from time-resolved and spectroscopic measurements of the cavity-spin system. \microscopic_simulation – Python code developed by Oliver Diekmann for microscopic spin–cavity simulations (output data not included due to size). \plotting_and_data_analysis – MATLAB analysis and plotting scripts developed by Wenzel Kersten (tested with MATLAB R2020a), including all routines used to generate the paper’s main and supplementary figures. Each MATLAB script contains a short internal README describing its purpose and usage.