BGO CRYSTALLINE FIBERS

A device for the fabrication of crystalline fibres (in gravity and at a controlled speed), of materials with relatively high melting point and/or an aggressive nature is described. The molten charge flows through a vertical nozzle of small diameter while inside the crucible a depression is maintained to control the flow of the material. Some crystalline fibres of BGO were drawn with a diameter less than 1 mm and length up to 24 cm. The pulling rate was about 1.5 cm min-1. Improvements are proposed to better the quality of the grown fibres which present high loss. The device can be also employed to pull single crystal fibres of alkali halides and other materials of interest in optoelectronics.