All-fiber mode-locked laser at 0.98 µm

Abstract

We developed a highly efficient double-clad Yb-doped polarization-maintaining fiber to be implemented for small-signal amplification near 0.976 mu m. The fiber was designed to have a relatively small mode field diameter compatible with standard step-index single-mode optical fibers. Another feature of the fiber was a small threshold for 0.976 mu m signal amplification, which was achieved by a creation of a thin inner cladding (80 mu m diameter). The unique design of the fiber allowed us to construct successfully an all-fiber picoseconds mode-locked laser at 0.98 mu m for the first time to the best of our knowledge.