Highly Efficient Yb-Doped Double Clad Photonic Crystal Fiber by Melting Technology

High-power fiber lasers have been developed rapidly since the invention of rare-earth-doped double clad fibers, while the scaling of output power is limited by nonlinear and thermal effects, fiber damage threshold as well. Photonic crystal fiber (PCF) has been used to mitigate this limitation due to large mode area and relatively low core index. In this work, we developed a simplified & flexible method to fabricate Yb
³⁺
doped double-clad (YDDC) PCF for fiber lasers. Systematic simulations and experiments were carried out for fiber characterization and laser performance evaluation. By improving the fabrication process of PCF, the YDDC PCF exhibited good properties, and the laser slope efficiency was measured above 86.8%. It is shown from the results that the proposed PCF fabrication method has huge potentials for applications of high-power fiber lasers.