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

Area of Science:

• Laser Physics
• Materials Science
• Nonlinear Optics

Background:

• Compact 2-μm passively Q-switched lasers with 2D material saturable absorbers face limitations in pulse energy and peak power due to concentration-dependent loss.
• These limitations restrict their application in high-instantaneous-intensity regimes.

Purpose of the Study:

• To develop a concentration-dependent dynamical model for passively Q-switched multi-segment, multi-concentration (MSMC) Tm:YAG lasers.
• To investigate how preparation concentration influences dynamic loss, net-gain buildup, absorber bleaching, and ultimately, pulse energy extraction and peak power.

Main Methods:

• Proposed a concentration-dependent dynamical model based on nonlinear transmission parameter mapping.
• Mapped modulation depth and nonsaturable loss to intracavity parameters qm(C) and qns(C).
• Introduced a concentration-dependent bleaching parameter, Isat(C).

Main Results:

• The model reveals how preparation concentration reshapes dynamic loss, governing laser performance metrics.
• Identified optimal concentration windows for Ti3C2Tx, MoS2, and WS2 (0.04, 0.03, and 0.05 mg/mL, respectively) for shortest pulse widths.
• Achieved experimental shortest pulse widths of 696.8 ns (Ti3C2Tx), 688.5 ns (MoS2), and 602.1 ns (WS2), with corresponding peak powers of 45.07 W, 47.53 W, and 34.25 W.

Conclusions:

• The developed model accurately predicts performance and guides the optimization of MSMC lasers.
• Concentration control is crucial for efficient pulse-energy extraction and achieving high peak powers in 2D material-based Q-switched lasers.
• The findings enable the design of lasers for high-instantaneous-intensity applications.