Hf ⁴⁺ Ion Concentration Dependence of Holographic Storage Properties in Hf:Fe:Cu:LiNbO₃ Crystals

Abstract

A series of Hf:Fe:Cu:LiNbO3 crystal with various concentrations of Hf 4+ ion doping are grown in air by the conventional Czochralski technique. The segregation coefficients of the Hf 4+, Fe3+, and Cu2+ ions in the crystals are carried out with an inductively coupled plasma‐atomic emission spectrometer. The birefringence gradient method is measured in order to analyze the optical homogeneity of Hf:Fe:Cu:LiNbO3 crystals. The holographic storage properties of Hf:Fe:Cu:LiNbO3 crystals are investigated by the two‐wavelength coupling experiment. The result shows that the writing time constant shortens from 529.3 to 214.4 s, and the dynamic range increases from 1.12 to 8.07 with increasing Hf 4+ content in the Hf:Fe:Cu:LiNbO3 crystals.