Spectroscopy and visible laser operations of a μ-PD grown Pr3+: LiYF4 single-crystal fiber

We report on the growth and visible laser operations of a single-crystal fiber of Pr3+: LiYF4(Pr:YLF), grown by the micro-pulling-down method (μ-PD). We performed spectroscopic analyses on the crystal and compared the results with a Czochralski-grown sample of the same material. These analyses proved the high optical quality of the fiber. Using a hemispherical cavity and pumping the crystal with an InGaN-based laser diode, we achieved laser emission in the orange, red and deep red regions. We measured the slope efficiencies of three transitions and studied the propagation of output beams. To the best of our knowledge, these are the first laser operations in a Pr:YLF single-crystal fiber grown by this method.