1178 nm all Yb-fiber laser source power-scaled by solid-core photonic bandgap fiber for 589nm generation

Here we report an 1178 nm all Yb-fiber laser source power-scaled by solid-core photonic bandgap fiber (SC-PBGF) for 589 nm generation. A 1.4 W output at 589 nm with an input power of 9 W at 1178 nm were obtained. One important advantage of PBGF is distributed filtering. Hence the gain spectrum can be designed artificially in an active-ion-doped SC-PBGF, desirable for long-wavelength Yb fiber laser operation. At first, 1178 nm amplification seeded with a non-polarized and linearly-polarized FRL was carried out with the core launched powers of 4 W and 2 W, respectively. As a result, an output power of 30 W at 1178 nm with was obtained with the slope efficiency of 58% and ASE free. A 25 W linearly-polarized output with 13 dB PER also was obtained. Next, the seed source was exchanged to an all-fiber linearly-polarized Yb fiber laser, which emits as high as a 3 W output power with a <40 pm bandwidth by cross splicing birefringence FBGs method.