A 500 fs, 248 nm ultra-short UV laser system for high speed recording devices and scintillators’ fluorescent excitation was introduced in the paper. The central part of the laser system is a Distributed Feedback Dye Laser(DFDL),namely, a dynamic image of coarse grating. The image length and the index of dye solution give the shortest pulse duration and changing the pitch of the grating results in a tunable spectrum. In experiments the working wavelength of the DFDL was adjusted to 496 nm and frequency doubled to 248 nm, which was match to that of the KrF excimer amplifier. The off-axis three pass amplification schemes and low saturation energy density of the excimer laser media made the intensity profile of the laser beam faily uniform, which was very attractive for the calibration of a high-speed recording device.An experiment to measure the fluorescent characteristics of a thin film ZnO∶Ga scintillator under UV laser excitation was demonstrated with the laser system. The interference of the scattered laser and the weak fluorescent signal was solved by using a collective imaging lens and a monochrometer.Obtained results show that the fluoresce spectrum is in the 380 nm to 410 nm with the central peak at 392 nm, and the fluorescene time of the scintillator is about 80 ps. Finally,the factors which may affect the measuring results were also discussed.