The growth of single-crystal fibres directly from source rods made of ultrafine powders

Abstract

By means of the laser-heated pedestal growth (LHPG) method, the growth of single-crystal fibres directly from source rods made of ultrafine powders is studied in this paper. The ultrafine powders were obtained by the sol-gel method and then were pressed into plates at room temperature. The source rods were simply cut from the plates. The advantages of this new technique are (i) good homogeneous source rods can be obtained because all components are mixed with their acid solutions, and the composition in the crystalline fibre grown from a source rod by the LHPG method will be uniform due to its high growth rate (1–2 mm min−1); (ii) the densified source rods can be pressed at room temperature since ultrafine powders are used, so contamination due to hot pressing or melting can be avoided; and (iii) highly doped crystal fibres can be easily obtained.