Dataset of Newton's rings images captured through the short face of a trapezoidal prism with a whispering gallery mode resonator positioned behind the prism. Each file corresponds to an applied piezo voltage over a voltage sweep decreasing in voltage steps of 0.1V (file names multiplied by 10). Both image data and oscilloscope data are included. Runs 18-27 & 42-53 use a green (530+-2 nm) filter and Runs 28-41 use a red (670+-2 nm) filter. crop-images.ipynb is used to process the raw images located in FullDataset.zip into grayscale jpg images, these processed images are then fed into Ringanalyzer-simplified.ipynb that calls from RingAnalyzer.py to convert the 2-D images to a signal-radius plot based on fits of an elliptical pattern, finding ellipticity, centroid, and rotation angle. process_run_logfit.m ultilizes the 1-D signal plot used to convert the piezo voltages to coupler distances, then a Lorentz fit is applied to the data from the oscilloscope - using lorentzfit.m to perform the fit. The final result is a log plot of the coupling linewidth as a function of distance. The data for resultant plots can be found in ProcessedDataset.zip and can be plotted by plot_processed_run.m. Figure 3.zip contains just the data subset used to generate Figure 3, with fig3.m to generate the figure.