Challenge and study for developing of novel single crystalline optical materials using micro-pulling-down method

Micro-pulling-down (μ-PD) method is a useful tool to search for new materials. This method allows us to prepare single crystalline materials quickly and relatively inexpensively. Grown crystals are of sufficient dimensions for all the necessary characterization by optical and luminescence methods, including photo- and radio-luminescence, decay kinetics and light yield measurements. Recent results obtained for laser and scintillator materials at Pr-doped Y3Al5O12, Lu3Al5O12, YAlO3, Y2SiO5, Lu2SiO5, fluorides like Ce-doped PrF3, mixed binary fluorides AEF2–REF3, (Ce:AE:(Gd,Y)F3, AE = Ba, Sr, Ca) and Yb- and Tm-doped RE2O3 (RE = Y, Lu, Sc) are summarized here. Practical importance of μ-PD method follows also from the shaped crystal growth aspect. It is possible to grow shaped and/or device-size crystals from the melt using a single step process. Recent improvement of μ-PD method makes the quality of μ-PD crystals comparable with those prepared by Czochralski (Cz), Bridgeman, or other classical growth techniques.