Growth of LiYF4 single-crystalline fibres by micro-pulling-down technique

Pure yttrium-lithium tetrafluoride (YLF) fibres have been successfully grown by the micro-pulling-down (μ-PD) technique in resistive mode. The influence of the growth atmosphere and starting melt composition on growth process were studied. YLF fibres grown from Li-rich melt (5 mol%) contain more than 70% of colourless, transparent and single-phase material. After a short length of the peritectic transient (≈10 mm), the fibres were uniform in diameter (800 μm) and quite long (≈60 mm). This work reports a suitable and reproducible growth process for high-quality YLF single-crystalline fibres.