Solid-state transverse Anderson localized fiber laser

For the first time, to our knowledge, an all-solid transverse Anderson localizing optical fiber laser is demonstrated. A combination of the molten core and stack-and-draw fiber fabrication techniques is used to produce a 112 µm core diameter fiber that is a random array of Yb-doped high index and passive low index regions. A localized channel first assists in the guidance of amplified spontaneous emission before stimulating laser action, which occurs in the same channel via mixed Anderson localization and step index wave-guiding. Threshold behavior and lasing are monitored with changing output power slopes, beam profiling, spectral content, fluorescence clamping, and temporal intensity. The average output power is stable, while the laser wavelength hops between 1066 and 1088 nm. Lasing is highly directional along the fiber axis.