Dual-Wavelength, Linearly Polarized All-Fiber Laser With High Extinction Ratio

We demonstrate a dual-wavelength linearly polarized all-fiber laser emitting 1- μm and 1.5- μm wavelengths with a total output power of 1.3 W. The laser consists of two pairs of fiber Bragg gratings (FBGs) fabricated on PM fibers to form a cavity and an Er/Yb co-doped fiber as a gain medium. A high extinction ratio of 23 dB is achieved using specially designed PM FBGs. The laser output has a narrow bandwidth of 26 pm at both 1057 and 1554 nm. When the dual-wavelength all-fiber laser is used to pump a PPLN crystal, the generation of mid-infrared emission at 3.3 μm is successfully demonstrated.