Crystal growth and properties of Yb:FAP laser crystal

A large and transparent Yb:FAP crystal with dimensions up to ∅30 mm×85 mm has been grown by the Czochralski method. The preparation of the raw material has been investigated. X-ray power diffraction studies of Yb:FAP crystal confirm that the as-grown crystal is isostructural with the FAP crystal. The crystalline quality has been studied using X-ray rocking curve analysis. The segregation coefficient of Yb3+ in the Yb:FAP crystal has been also determined. Linear thermal expansion coefficients in [0 0 1] and [1 0 0] directions have been measured in the 30-800 °C temperature range.