47.53 W high-peak-power passively Q-switched MSMC Tm:YAG laser

For compact 2 μm passively Q-switched lasers based on two-dimensional-material saturable absorbers, concentration-dependent loss allocation can limit pulse-energy extraction and tens-of-watts peak-power operation, restricting their use in high-instantaneous-intensity applications. To address this issue, this work proposes a concentration-dependent dynamical model for passively Q-switched multi-segment, multi-concentration (MSMC) Tm:YAG lasers based on nonlinear transmission parameter mapping. It reveals how the preparation concentration reshapes dynamic loss, thereby governing net-gain buildup, absorber bleaching, loss release, threshold, pulse-width compression, and peak power. The modulation depth and nonsaturable loss are mapped to intracavity q_m(C) and q_ns(C), while I_sat(C) is introduced as a concentration-dependent bleaching parameter. For Ti₃C₂T_x, MoS₂, and WS₂, the predicted compression windows are 0.04, 0.03, and 0.05 mg/mL, matching the experimental shortest pulse widths of 696.8, 688.5, and 602.1 ns. These windows also sustain efficient pulse-energy extraction, giving peak powers of 45.07, 47.53, and 34.25 W.