Bridgman growth of LiYF4 and LiLuF4 crystals for radiation-balanced lasers

Single crystals of LiYF₄ (YLF) and LiLuF₄ (LLF) doped with Yb³⁺, Tm³⁺, or Ho³⁺ are attractive materials for enabling radiation balanced lasers (RBLs) operating in the 1–2 μm wavelength range. High material purity and short growth times are critical for exploring and optimizing the performance of these materials. We show that the Bridgman growth method can yield single crystals within ~1 week and requiring only a few grams of the respective starting materials. We report on progress growing YLF and LLF crystals by the vertical Bridgman method and discuss the challenges posed by the incongruent melting properties of YLF. The congruently-melting LLF is found to be an attractive candidate material for RBL applications.