Fig. 1. Basic structure and experimental results of single-frequency fiber laser^[16]. (a) Experimental setup; (b) output and backward powers at different pump powers; (c) polarization degrees at different output powers

Fig. 2. Experimental results of linearly-polarized narrow-linewidth fiber laser^[42]. (a) Output and backward powers at different pump powers; (b) polarization extinction ratios at different output powers; (c) spectrum at maximum output power

Fig. 3. Structure and experimental results of all-fiber polarization-maintaining laser ^[49]. (a) Basic experimental structure; (b) output powers at different pump powers; (c) output spectra at seed power and maximum output power

Fig. 4. Structure and experimental results of polarization-maintaining superfluorescent fiber amplifier^[9]. (a) Basic experimental structure ; (b) output powers at different pump powers; (c) output spectra at different output powers

Fig. 5. Supercontinuum generation through high peak power pulse pumping of polarization maintaining photonic crystal fiber^[63].

Fig. 6. Experimental setup and results of supercontinuum laser source based on polarization maintaining master oscillator power amplification structure^[67]. (a) Experimental setup; (b) output power versus pump power (inset is spectrum under highest power); (c) full-spectrum polarization degrees at different output powers

Fig. 7. Supercontinuum source based on random fiber laser structure^[70]. (a) Experimental setup; (b) output spectra at different pump powers; (c) polarization extinction ratios at different pump powers

Fig. 8. Structure and test results of narrow linewidth fiber laser^[76]. (a) Schematic of structure; (b) output power versus pump power; (c) output spectrum at maximum power

Fig. 9. Structure and test results of 1950 nm single-frequency fiber laser^[86]. (a) Experimental setup; (b) output power versus pump power (inset is polarization extinction ratio versus output power); (c) output spectrum at maximum power

Fig. 10. Structure and test results of 1120 nm fiber laser^[97]. (a) Experimental setup; (b) output power versus pump power;

Fig. 11. Structure and test results of ytterbium-doped Raman amplifier^[110]. (a) Experimental setup; (b) output power versus pump power; (c) output spectra at different output powers

Fig. 12. Structure and test results of kilowatt-level linearly-polarized random fiber laser^[115]. (a) Experimental setup; (b) output power and backward power versus pump power; (c) output spectrum at maximum output power

Fig. 13. Structure and test results of kilowatt-level wavelength tunable linearly-polarized Yb-doped fiber laser^[118]. (a) Experimental setup; (b) output power versus pump power; (c) output spectra at maximum output power

Fig. 14. Raman fiber laser with two kinds of structures^[123]

Fig. 15. Structure and test results of multiwavelength fiber laser^[127]. (a) Structural diagram; (b) schematic of independent intensity adjustment of each channel for multiple wavelengths

Fig. 16. Structure and test results of self-sweeping Tm-doped fiber laser^[130]. (a) Structural diagram; (b) schematic of self-sweeping;

Fig. 17. Structure and test results of nanosecond pulsed fiber laser^[152]. (a) Structural diagram; (b) output power and backward power versus pump power; (c) pulse profiles

Fig. 18. Structure and test results of picosecond pulsed fiber laser amplifier^[162]. (a) Structural diagram; (b) output power versus pump power; (c) pulse width results measured by autocorrelator

Fig. 19. Structure and test results of femtosecond pulsed fiber laser amplifier based on active polarization control ^[175]. (a) Structural diagram; (b) output power versus pump power; (c) polarization extinction ratios of laser under open-loop and closed-loop controls

Fig. 20. Polarization dependence of SBS intensity^[181]. (a) SBS intensity versus incident angle at different powers; (b)incident angles corresponding to highest and lowest SBS intensity values

Fig. 21. Polarization evolutions of fundamental mode and higher-order modes at different powers^[197]

Table 1. Research progress of high-power linearly-polarized single-frequency fiber laser in recent years

Table 2. Research progress on high-power linearly-polarized conventional-linewidth fiber laser