Fig. 1. Schematic diagram of the high-energy sub-nanosecond VUV laser at 177 nm. Inset: detailed schematic structure of the KBBF-PCD in our experiment.

Fig. 2. Calculated conversion efficiency from 355 to 177 nm versus KBBF effective crystal length for Gaussian beam G = 1 and SGB G = 4 at the pump energies of 100 and 75 mJ with a beam diameter of 5 mm.

Fig. 3. Dependence of output energy of the 177 nm laser and conversion efficiency of the pump energy at 355 nm.

Fig. 4. Simulated 355 and 177 nm pulse temporal profiles. Inset: measured pulse profile of the 355 nm laser.

Fig. 5. Measured spectrum of the pump laser and near-field 2D beam spatial profile at 355 nm.

Fig. 6. Fluorescence patterns on the fluorescence glass induced by the residual beam at 355 nm and the generated beam at 177 nm.