Dual-wavelength Brillouin-erbium fiber laser with tunable wavelength spacing

A novel wavelength-spacing tunable dual-wavelength Brillouin-erbium fiber laser is proposed and demonstrated experimentally. The dual-wavelength lasing is achieved by combining the erbium-doped fiber laser (EDFL) and the first-order Brillouin laser using a 4 m high nonlinear fiber (HNLF) as Brillouin gain medium. The evolutionary power spectrum of the EDFL and the first-order Brillouin laser are investigated through adjusting the output power of tunable laser source (TLS) and 980 nm pump. The high stability of the single-and dual-wavelength operation are experimentally verified by the measured wavelength variation of <= 0.01 nm and power fluctuation of <= 1.6 dB within 100 min. With the good tunability of the TLS, the wavelength spacing of a dual-wavelength operation could be achieved in the pass band of the FBG. The fiber laser will find potential applications in fiber sensing and microwave photonics areas.