Growth and optical activity of Ca ₃NbGa ₃Si ₂O ₁₄ single crystal

Crystals of Ca3NbGa3Si2O14 (CNGS) with ordered langasite structure were grown using the Czochralski method along the Cartesian X axis [110]. The as-grown crystals exhibit high optical quality and structure perfection. Optical activities were obtained by measuring polarised transmission at various wavelengths between crossed polarisers using a TU-1900 spectrophotometer and we found that CNGS crystals showed very large values of rho.