Laser performance of high optical quality 4 at.% Pr³⁺: Sr_0.7La_0.3Mg_0.3Al_11.7O₁₉ (Pr:ASL) single crystals

In this work, we present the visible laser performance of improved optical quality Czochralski-grown 4 at.% Pr³⁺-doped Sr_0.7La_0.3Mg_0.3Al_11.7O₁₉ (Pr:ASL) single crystals in the deep red (726 nm), the red (645 nm) and the orange (620 nm) range using two different pumping sources. Using a high beam quality frequency doubled Ti:sapphire laser with 1 W output power as pump source, deep red laser emission was reached at a wavelength of 726 nm with 40 mW of output power and a laser threshold of 86 mW. The corresponding slope efficiency was 9%. At 645 nm in the red, up to 41 mW of laser output power were obtained with 15% slope efficiency. Moreover, orange laser emission at 620 nm was demonstrated with 5 mW output power and 4.4% slope efficiency. Using a 10 W multi-diode module as pumping source allowed to obtain the highest output power of a red and deep-red diode-pumped Pr:ASL laser to date. The respective output powers at 726 and 645 nm reached 206 mW and 90 mW.