Generation of large energy 355 nm ultraviolet light based on a pulse-pumped Nd:YVO4 amplifier with aperture-like...

A large energy pulsed 355 nm ultraviolet (UV) light with a pulse repetition rate (PRR) of 10 kHz is presented in this paper, which is implemented by employing a two-stage Nd: YVO₄ master oscillation power amplifier (MOPA) with the aperture-like structure. By optimizing the mode-matching between the seed and pump laser of the amplifiers, an aperture-like structure can be skillfully constructed for the laser crystal. In this case, the amplified spontaneous emission (ASE) can be effectively filtered out, and its influence on the amplified fundamental-wave laser pulse can be eliminated. On this basis, a 355 nm UV light with an average power and energy of up to 40 W and 4 mJ is obtained through third harmonic generation. The achieved pulse width is 7.8 ns. To the best of our knowledge, it is the maximum output power of 10 kHz 355 nm UV light with high beam quality and narrow pulse width realized via Nd: YVO₄ crystals. We think that the presented method is conducive to attaining a large energy UV light with high spectral purity.