High-power-class QCW red laser bars and stacks for pump and direct application

We present an overview of collaborative research between FBH (diode lasers) and Coherent|Dilas (packaging) to enable applications using red diode lasers. We summarize recent progress, focusing on the development of laser bars for highintensity pulse-pumping of alexandrite lasers. Specifically, high fill factor 1-cm bars packaged and tested (25°C, 10 Hz, 600 μs) on passively cooled mounts confirmed peak power of more than 350 ? (> 0.2 ? per bar), where efficiency was ~35% at 665 nm wavelength. Power was limited by thermal rollover. No evidence was seen for lateral lasing. Passively cooled 8-bar stack performance is presented, confirming a reliable optical power of 250 W/bar in stack format.