Fig. 1. Structural diagram of all-PM Yb-doped NALM mode-locked fiber oscillator^[26]

Fig. 2. Structural diagram of all-PM-NPE fiber oscillator^[27]

Fig. 3. Experimental setup of master oscillator power amplifier ^[30]

Fig. 4. Diagram of integrated CPA system with PM fiber^[33]

Fig. 5. Diagram of high-power femtosecond fiber CPA system^[38]

Fig. 6. Diagram of large-pitch PCF chirped-pulse amplification system ^[42]

Fig. 7. Diagram of fiber chirped pulse amplification system^[44]

Fig. 8. Diagram of high energy femtosecond fiber CPA system^[47]

Fig. 9. Diagram of all-polarization-maintaining NALM mode-locked fiber oscillator, and diagram of 1.03 μm picosecond CPA system^[48]. (a) Diagram of all-polarization-maintaining NALM mode-locked fiber oscillator; (b) diagram of 1.03 μm picosecond CPA system

Fig. 10. Diagrams of experimental setups of domestic PCF amplification. (a) Diagram of all-fiber oscillator and pulse stretcher; (b) diagram of double-cladding fiber amplifier; (c) diagram of domestic PCF main amplifier

Fig. 11. Spectrum and autocorrelation curve of mode-locked oscillator. (a) Spectrum; (b) autocorrelation curve

Fig. 12. Output spectrum after primary pre-amplification, and pulse shape broadened by passive fiber. (a) Output spectrum after primary pre-amplification; (b) pulse shape broadened by passive fiber

Fig. 13. Output spectrum and pulse shape of 30/250 μm ytterbium doped fiber amplifier. (a) Output spectrum; (b) pulse shape

Fig. 14. Output power as a function of pump power in main amplification stage, and autocorrelation trace of compressed output pulse after main amplification. (a) Output power as a function of pump power in main amplification stage; (b) autocorrelation trace of compressed output pulse after main amplification

Fig. 15. Diagram of end-pumped thin rod Yb∶YAG amplifier^[53]

Fig. 16. Evolution of fraction of pump power absorbed in central part of SCF, and temperature distribution of SCF pumped facet in Taranis module and conventional mounting technique^[56]. (a) Evolution of fraction of pump power absorbed in central part of SCF; (b) temperature distribution of SCF pumped facet in Taranis module and conventional mounting technique

Fig. 17. Diagram of Yb∶YAG thin rod and multi-pass disk amplification system^[61]

Fig. 18. Diagram of SCF regenerative amplifier^[67]

Fig. 19. Diagram of Yb∶YAG double-pass amplifier^[71]

Fig. 20. Diagram of CPA system with fiber frontend and free-space Yb∶YAG amplifier^[74]

Fig. 21. Diagram of hybrid MOPA system with Yb-fiber and Yb∶YAG thin-rod^[76]

Fig. 22. Diagrams of optical path of sidecast crystal rod trapping ASE for direct water cooling at side and end angles. ASE decreases laser gain stored in annular region of crystal rod^[77]

Fig. 23. Diagram of two-stage double-end pumped Φ2×(5+40+5) mm Yb∶YAG bonding thin rod amplifier, and output powers of first stage amplifier and second stage amplifier. (a) Diagram of two-stage double-end pumped Φ2×(5+40+5) mm Yb∶YAG bonding thin rod amplifier; (b) output power of first stage amplifier; (c) output power of second stage amplifier

Fig. 24. Diagrams of reverse-pumped double-pass amplification and dual-end-pumped four-pass amplification, output powers of Yb∶YAG crystals of different specifications during reverse pumping and dual-end-pumped, and beam quality factor of SCF dual-end-pumped four-pass amplification. (a) Diagram of reverse-pumped double-pass amplification; (b) diagram of double-ended pumped four-pass amplification; (c) output power of Yb∶YAG crystals of different specifications during reverse pumping; (d) output power of