Alexandrite Lasers Operating with High-Power Blue-Diode-Pumping

Alexandrite is a solid-state laser with excellent thermal properties for power scaling and together with its broad wavelength tunability (~720 - 820 nm) provides potential for applications in remote sensing, biophotonics, and quantum technologies. Until recently, diode pumping has been predominantly performed by red semiconductor lasers near 638nm, however, blue diodes operating near 445nm have higher emitter power, higher-brightness and low-cost ($/W) making them attractive as alternative pump sources for Alexandrite lasers. This work focuses on the investigation of Alexandrite lasers pumped by a high-power fibre-delivered blue diode module achieving record blue-pumped powers and provides in-depth laser performance characterisation.