Masaki Seguchi

1.4-kW Nd:YAG slab laser with a diffusive closed-coupled pump cavity

A high-power high-efficiency Nd:YAG slab laser with lamp pumping is developed by use of a novel diffusive-closed coupled lamp pump cavity. In cw-mode operation, 1.45 kW of output power is obtained with a slope efficiency of 5.0%. In pulsed-mode operation (50 pulses/s, 25% pulse duty), 1.4 kW of output power is obtained with a slope efficiency of 4.3%. The output power per unit volume is 45 W/cm(3). To our knowledge, these output powers and the power per unit volume are the highest obtained for the single-head Nd:YAG slab laser with lamp pumping.

High-power high-brightness diode-pumped solid state laser for precise laser processing

We have proposed a highly efficient and high-brightness quasi-cw Nd:YAG rod laser with a novel-side-pumping design using micro-lens free diode-stacks. We achieved 320W output power with 28-% electrical-to-optical efficiency, which is, to our knowledge, the highest efficiency reported for diode- pumped solid-state lasers. We generated the high quality beam of M2equals4 with the output power of 500W while maintaining the electrical-to-optical efficiency of 20%. We also demonstrated through-hole formation of 1mm thick copper plate using the high brightness laser beam and successfully obtained round holes with the diameter of less than 40 micrometers .