Dataset for Beam Quality Characterization of Tunable 230–400 nm Ultraviolet Dispersive Waves in a Hollow Capillary Fiber

This dataset contains beam quality characterization results of tunable ultraviolet dispersive waves in the 230–400 nm range generated in a hollow capillary fiber. It mainly includes M² values at different wavelengths, beam-width evolution data along the x and y directions, near-field and far-field beam images, as well as related measurement conditions and auxiliary parameters. The data were obtained based on the ISO 11146 second-moment method. A commercial M² analyzer and a manual second-moment fitting method were employed for different wavelength regions, with cross-validation performed in part of the overlapping range. This dataset can support studies on the spatial quality of ultraviolet dispersive waves, focusing capability analysis of ultraviolet ultrafast sources, and M² measurement methods in the ultraviolet region.