High-average-power, high-repetition, diode-pumped third-harmonic Nd:YAG laser

Summary form only given. Ultraviolet or visible frequency converted diode-pumped solid-state laser is one of the most promising candidates for drilling or trimming of printed circuit boards. To achieve higher throughput, it is essential to enhance average output power at high repetition frequency. Although, more than 20 W 351-nm average output power has been reported with an intracavity-frequency-tripled Nd:YLF laser, it's pulse repetition frequency was 2.5 kHz, and average output power of high repetition 355-nm beam sources were limited at a level of 5 W. We enhanced the average output power of a third harmonic Nd:YAG laser up to 18 W, at the repetition rate of 25 kHz. This is what we believe to be the highest number obtained with extracavity-frequency-converted solid-state lasers.