Vertical Bridgman growth and optical properties of doped Bi 12 SiO 20 crystals

The core‐free BSO crystals with high optical quality, doped with NiO, Sb 2 O 3 , V 2 O 5 , Nb 2 O 5 , Ta 2 O 5 , and P 2 O 5 , have been grown by the vertical Bridgman (VB) method for the first time. The “interface” segregation coefficients of the above‐mentioned dopants in BSO with values of 0.014, 0.162, 0.704, 0.039, 0.077, and 0.976, respectively, have been approximately evaluated according to the diffusive solute transport regime with the assumption of negligible natural convection in the melt. The transmission spectra of various doped BSO crystals have been measured in the range from 300 to 700 nm. A blue shift of the transmission edge in Ni‐, Sb‐, and P‐doped BSO and a red shift in Nb‐ and V‐doped BSO have been found as compared to undoped BSO. The modification in the absorption amplitude implies that the photorefractive performances of BSO crystals may be improved through doping.