Growth and characterization of LiYF4:Nd single crystal fibres for optical applications

The micro-pulling-down technique has been employed to grow long and regular in diameter Nd-doped LiYF4 single crystal fibres. The effective distribution coefficient of Nd3+ ion in the YLF crystal fibres was estimated. The optical absorption and emission of an YLF:Nd bulk crystal and YLF:Nd crystal fibre were compared. The absorption bands of the Nd3+ ion, in the visible and in the near infrared, are similar for both materials. The fibre showed an emission band with maximum at 1047 nm and luminescence lifetime of the 4F3/2 state of 390 μs while the bulk crystal exhibits the luminescence lifetime of 460 μs.