Fig. 1. Schematic diagram of frequency doubling device of continuous fiber laser

Fig. 2. Spectrum of narrow bandwidth grating

Fig. 3. Experimental results of fiber laser based on common commercial grating

Fig. 4. Fundamental frequency laser is divided into two beams with almost equal power, namely s-polarized laser and p-polarized laser

Fig. 5. Powers of p-polarized light and s-polarized light varying with current

Fig. 6. Frequency doubling of p-polarized laser (532 nm green laser is obtained with 7.3 W power)

Fig. 7. 532 nm green laser is obtained with 11.6 W power when fundamental laser source is natural light

Fig. 8. Variation of 532 nm green laser power with current and change of frequency doubling efficiency with current. (a) Using p-polarized laser as frequency doubling source; (b) after removing PBS and half wave plate

Fig. 9. Spectra of fundamental frequency laser from different lasers. (a) Narrow bandwidth fiber laser; (b) common commercial fiber laser