Fig. 1. Experimental setup of MOPA fiber laser operating near 980 nm

Fig. 2. Output properties of seed light after the MFA. (a) Variation of seed power with pump power; (b) variation of output spectrum with seed power; (c) zoom-in spectra around 980 nm; (d) beam quality of seed light at the maximum power

Fig. 3. Output properties of seed light after band-pass filter. (a) Variation of seed power with pump power; (b) variation of output spectrum with seed power; (c) zoom-in spectra around 980 nm; (d) beam quality of seed light at maximum power

Fig. 4. Experimental results of fiber laser with 0.56-m-long gain fiber used in the amplifier. (a) Variation of output power with pump power; (b) variation of output spectrum with output power; (c) zoom-in spectra around 980 nm; (d) beam quality at the maximum output power

Fig. 5. Experimental results of fiber laser with 0.47-m-long gain fiber used in the amplifier. (a) Variation of output power with pump power; (b) variation of output spectrum with output power; (c) zoom-in spectra around 980 nm; (d) beam quality at the maximum output power