Crystal Fiber Waveguide

Compare with glass optical waveguides, the crystal fiber waveguide adopted rare earth ion doped YAG crystals as core and cladding, which has higher thermal conductivity and can greatly increase the upper limit of output lasing power. More importantly, these crystal fiber waveguides have much lower SBS gain coefficient than silica glass fibers. By engineering the size and materials of both core and cladding, we developed a large mode area Yb:YAG crystal waveguide under single mode beam quality. The 400um x400um square core with 1mm diameter Er:YAG cladding is an ideal material for high energy ultrafast lasers.