Near-diffraction-limited, high-energy, electro-optically Q-switched Nd:YAG Innoslab laser based on a slab BBO Pockels cell

For Pockels cells required by high-energy lasers, the current mainstream design adopts a square aperture. Pockels cells assembled with slab-shaped electro-optic crystals are a more suitable choice for Nd:YAG Innoslab hybrid cavities that directly output large single-pulse energies or for ring-cavity regenerative amplifiers with large cavity-mode size. This study constructs a Pockels cell using a single large slab-shaped BBO crystal, focusing on enhancing electric field uniformity within the crystal and reducing assembly stress, thereby achieving consistent optical field modulation across the entire aperture. The experiment first tested the extinction ratio, conoscopic interference pattern, and extracavity modulation characteristics of the electro-optic switch. The developed Pockels cell was then applied to a continuously pumped and pulsed-pumped Nd:YAG hybrid cavity laser. During continuous pumping, we attained an output power of 37.54 W, a repetition rate of 2 kHz, and a pulse width of 6.5 ns. During the pulsed pump, we also obtained an output energy of 21.3 mJ with a repetition rate of 100 Hz and a pulse width of 7.77 ns. Both of these results exhibited near-diffraction-limited beam output. Given the performance verification of the proposed packaging in our work, we expect this high-performance Pockels cell to provide support for the advancement of integrated optical laser systems and high-resolution metrology.