Joule-level, 20 ns Cr-Tm-Ho:YAG master oscillator power amplifier system

We report on a compact, flash-lamp-pumped Cr-Tm-Ho:YAG (CTH:YAG) master oscillator power amplifier (MOPA) system operating at room temperature. The actively Q-switched oscillator produces 20 ns seed pulses at 2087 nm with an energy of 265 mJ. After a two-stage amplification, the system delivers a maximum output energy of 1.24 J, while maintaining the 20 ns pulse duration. To the best of our knowledge, this work represents the first demonstration of a joule-level, nanosecond CTH:YAG amplifier system, achieving the highest single-pulse energy yet reported from such a configuration. These results establish flash-lamp-pumped CTH:YAG as a viable architecture for developing high-energy, cost-effective 2 µm laser sources.