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.