High Efficiency Fiber Laser for Advanced Accelerator

The DOE needs a single-polarization mode-locked high-power 2-micron fiber laser for an advanced laser electron accelerator. The 2-micron laser wavelength allows for larger accelerator dimensions and the acceleration of more charge, compared to the 0.8 micron Ti:Sapphire laser. The other advantage of a 2-micron wavelength is the possibility of using silicon as opposed to quartz as a material for the accelerator. This project will develop a highly efficient high-power 2-micron mode-locked fiber laser using innovative polarization-maintaining Tm-doped fibers, with an extremely large single-mode core diameter. Phase I designed and fabricated Tm­-doped glasses and fibers, characterized the spectroscopic properties of Tm ions, demonstrated a highly efficient near-2-micron fiber laser with a slope efficiency of 68%, and successfully demonstrated a mode-locked 2-micron fiber laser. In Phase II, the mode-locked 2 micron fiber lasers will be further optimized, and a prototype high-power mode-locked 2-micron fiber laser will be built. Commercial Applications and other Benefits as described by the awardee: A high-power mode-locked 2-micron fiber laser should find a wide range of uses, including materials processing, remote sensing, and bio-medical applications.