Crystal growth and high reflectivity self-pumped phase conjugation of (Cu, Ce)-doped (KNa)_(0.1)(Sr_(0.6)Ba_(0.4))_(0.9)Nb_2O_6 crystal

Potassium sodium strontium barium niobate (KNSBN) crystal is one of the important photorefractive ferroelectric crystal materials, not only having good photorefractive properties, but also many advantages over other photorefractive crystal materials: (ⅰ) it is easy to grow in large size, (ⅱ) neither twinning nor poling problems exist; (ⅲ) it can accommodate a wide range of solution; (ⅳ) it is easy to be doped with many kinds of dopants.