Theoretical analysis on gain and thermal performance of Tm:YLF-based 10 kW-level laser amplifier

Recent advances in 2 μm laser technology demonstrate significant potential to replace conventional 10.6 μm lasers for generating efficient extreme ultraviolet (EUV) light sources. The multi-pulse extraction (MPE) technique, synergized with gain media exhibiting long fluorescence lifetimes (e.g., Tm:YLF), presents a viable strategy for achieving high-average-power 2 μm lasers. However, achieving kW-level average power output at 2 μm remains an area requiring further exploration. To investigate this, we propose potential technical pathways through comprehensive theoretical analyses of gain performance and thermal effects in Tm:YLF amplifiers. The gain performance model derived from laser rate equations and finite element analysis (FEA) simulations can further reveal temperature and thermal stress distributions in the crystals. These theoretical results exhibit excellent agreement with reported experimental data. Our results indicate that Tm:YLF is a suitable candidate for developing 2μm laser systems with high repetition rates and high average power (>10 kW). We also highlight critical technical challenges requiring further experimental validation, including thermal management optimization and MPE efficiency enhancement.