Fig. 1. Schematic diagram of the experimental setup of QCW-TDFL（HR：high reflector；OC：output coupler；CPS：cladding power stripper）

Fig. 2. Energy level structure of Tm³⁺ ions

Fig. 3. Emergence and suppression of relaxation oscillations：（a），（b）observed relaxation oscillations；（c），（d）relaxation oscillations are suppressed

Fig. 4. Output spectra and cross sections of different gain fibers: (a) output spectrum and cross section figure of gain fiber A; (b)output spectrum and cross section figure of gain fiber B

Fig. 5. Mode field distributions of different gain fibers：（a）LP₀₁ of gain fiber A；（b）LP_11a of gain fiber A；（c）LP_11b of gain fiber A；（d）LP₀₁ of gain fiber B

Fig. 6. Simulation of the relationship between fiber bending diameter and mode limiting loss

Fig. 7. Curves of laser output peak power under different pump peak power at 1 kHz

Fig. 8. Maximum power output pulse train with 10% duty cycle

Fig. 9. Beam quality fitting curves with near-field spot distribution