Over 10 W Output Linearly-Polarized Single-Stage Fiber Laser Oscillating Above 1160 nm Using Yb-Doped Polarization-Maintaining Solid Photonic Bandgap Fiber

Abstract

We propose an all-fiber linearly-polarized single-stage fiber laser oscillating above 1160 nm employing a low-loss Yb-doped polarization-maintaining solid photonic bandgap fiber (Yb-PM-SPGF) as a laser source for a yellow-orange frequency-doubling laser. We also present a new fabrication method for Yb-PM-SPBGF to reduce fiber attenuation in its photonic bandgap for increasing laser output power and improving slope efficiency. The attenuation of a fabricated Yb-PM-SPBGF is below 20 dB/km at 1180 nm, which is as low as that of a conventional Yb-doped fiber. All-fiber linearly-polarized single-stage fiber laser oscillating at 1180 nm using the fabricated Yb-PM-SPBGF is demonstrated. ASE and parasitic lasing in the wavelength range from 1030 nm to 1130 nm are suppressed and eliminated thanks to the filtering effect of the fiber. A 10.8 W output power is successfully achieved with a slope efficiency of 56% and a conversion efficiency of 50% by high-power 976 nm pumping. A spectral width of less than 0.05 nm, a polarization extinction ratio of more than 20 dB and nearly diffraction limited beam quality in output light are achieved. These results indicate that our proposed fiber laser can realize a compact and high-power yellow-orange frequency-doubling laser.