Fig. 1. Experimental setup diagram of actively Q-switched RFL based on RPS-FBG

Fig. 2. Reflectance and transmission spectra of RPS-FBG

Fig. 3. Pulse sequences of RFL under different pump powers when modulation signal amplitude is 2 V and frequency is 10 kHz

Fig. 4. Effects of pump power on RFL output spectrum and peak power. (a) Output spectra; (b) peak power

Fig. 5. Pulse sequences of RFL under different modulation frequencies when pump power is 80 mW and modulation signal amplitude is 2 V

Fig. 6. Temporal pulse sequences of RFL under different modulation frequencies when pump power is 80 mW and modulation signal amplitude is 2 V. (a) 7 kHz; (b) 19 kHz; (c) 21 kHz; (d) 23 kHz; (e) 27 kHz; (f) 31 kHz; (g) 36 kHz; (h) 41 kHz; (i) 48 kHz; (j) 52 kHz; (k) 56 kHz; (l) 62 kHz

Fig. 7. Output spectra of RFL under different modulation frequencies when pump power is 80 mW

Fig. 8. Experimental result of pulse bifurcation in RFL under combined effects of pump power and modulation frequency

Fig. 9. Experimental setup diagram of actively Q-switched random fiber laser based on optical injection

Fig. 10. Temporal pulses under different radio-frequency signal frequencies. (a) 10.0 kHz; (b) 3.0 kHz; (c) 2.0 kHz; (d) 0.7 kHz

Fig. 11. Temporal pulses under different pump powers without optical injection. (a) 73.0 mW; (b) 120.5 mW; (c) 172.3 mW

Fig. 12. Temporal pulses under different pump powers when optical injection power is 8 dBm. (a) 73.0 mW; (b) 120.5 mW ;(c) 172.3 mW

Fig. 13. Spectrum at pump power of 73 mW under constant optical injection with central wavelength of 1548.5 nm and power of 8 dBm