High-power Nd:YLF laser end pumped by a diode-laser bar

Abstract

We report on a Nd:YLF laser that is end pumped by a quasi-cw diode-laser bar. A fiber-optic coupler was developed to collimate and transform the cross section of the diode-laser radiation for increased spatial overlap with the TEM00 mode of the Nd:YLF laser. With 12.3-mJ, 200- μs pump pulses, an optical-to-optical efficiency of 25% and a slope efficiency of 28% were obtained in free-running operation. In Q-switched operation with 19.25-mJ, 400-μs pump pulses, peak powers as high as 210 kW with 3-mJ pulse energy were obtained.