Fig. 1. Experimental setup of the 1.6 µm SF EDFL.

Fig. 2. Transmission spectrum of the FP-FBG and reflection spectrum of the FBG.

Fig. 3. Schematic of the TCSRs filter.

Fig. 4. Simulated transmission spectrum of TCSRs.

Fig. 5. (a) Output spectrum of the EDFL at the pump power of 345 mW; (b) output OSNR of the EDFL at different pump powers.

Fig. 6. Laser output beating signal diagram. (a) FBG only; (b) with FBG and FP-FBG; (c) with FBG, FP-FBG, and TCSRs.

Fig. 7. Output stability of EDFL. (a) Central wavelength and output power; (b) single-longitudinal-mode state.

Fig. 8. Schematic of delayed self-heterodyne interferometry for laser linewidth measurement.

Fig. 9. (a) Relationship between ΔS and Δν; (b) actual detected power spectrum and fitting curve.