Yb-Doped Large Mode Area Fibers Produced by Powder Sintering for High Peak Power Narrow-Linewidth Laser Source

In the last decades, Yb-doped fiber lasers proved their capabilities to deliver high average power in pulsed regime with excellent efficiencies and high beam quality [1]. To mitigate the non-linear effects that limit this technology at high peak power, Large Mode Area (LMA) fibers were developed with numerous designs and technologies. LMA fibers based on standard step-index technology [2] are relatively simple to manufacture, but they are typically limited below 30μm in Mode Field Diameter (MFD) for wavelengths around 1μm by index control limitations in the vapor deposition technique. On the other hand, more complex designs like Photonic Crystal Fibers (PCF) can be used to reach larger MFDs [3], but with a significant increase in complexity and cost.