Fig. 1. Typical oscillator configuration

Fig. 2. Typical amplifier configuration

Fig. 3. Structural diagram of MOPA based on gain- switched thulium-doped fiber

Fig. 4. Influence of pump laser pulse width on output laser characteristics

Fig. 5. Influence of pump laser repetition rate on output laser characteristics

Fig. 6. Influence of cavity length on output laser characteristics

Fig. 7. Influence of gain fiber length in oscillator on output laser characteristics

Fig. 8. Influence of gain fiber length in amplifier on laser output power

Fig. 9. Output power of laser oscillator versus input power of 1550 nm laser

Fig. 10. Output laser pulse shape of laser oscillator

Fig. 11. Output power of laser amplifier versus input power of 793 nm pump source. Inset is long-term stability test result of amplifier output power

Fig. 12. Output laser pulse shape of laser amplifier