Efficient diode bar-pumped intracavity-doubled Nd:YVO/sub 4/ laser using stacked-glass plate beam shaper

Summary form only given. We describe efficient operation in an intracavity-doubled, diode bar-pumped Nd:YVO/sub 4/ laser using a newly designed stacked-glass plate (SGP) beam shaper. We used 20-W diode bars as pump source. It has 10 mm/spl times/1 /spl mu/m emitting dimensions with a divergence of 20/spl deg//spl times/50/spl deg/ (full angle) for horizontal and vertical dimensions. The SGP beam shaper consists of two sets of 15 SGPs. Each plate (25 mm square) is 1.5 mm thick and is stacked with a twist offset. The diode bar beam collimated in the vertical plane is condensed at the entrance of the first SGP and divided into 15 beams. Each beam is refracted at a different angle and transmitted in a different direction in a glass plate. As a result, each beam is emitted with a 1.5-mm gap in the vertical plane from the first SGP is exactly the same as the first one but positioned at a right angle to the first one. The second SGP causes all 15 beams from the SGP to be overlapped in the horizontal plane. As a result, M/sup 2/ of the diode bar beam is improved by a factor of about 15 in the horizontal dimension. Additionally, this beam shaper has a high transmission of 93% for the diode bar beam. The 15 stacked beams are then focused with a cylindrical and a spherical lens.