Growth and photorefractive properties of an Fe-doped near-stoichiometric LiNbO3 crystal

• Published in: Journal of physics. D, Applied physics Vol. 38; no. 12; pp. 2013 - 2016
• Main Authors: Zhang, Tao, Wang, Biao, Fang, Shuangquan, Ma, Decai
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 21.06.2005; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Infrared and raman spectra and scattering; Nonlinear optics; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optics; Other nonmetallic inorganics; Phase conjugation, optical mixing; photorefractive and kerr effects; Physics; Photovoltaic effects; Space-charge-limited conduction; Photorefractive effect; Impurities; Doping; Lithium niobates; Iron additions; Infrared spectra; Absorption coefficients; Gain
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/38/12/024

A near-stoichiometric LiNbO3 crystal with 0.02 wt% Fe2O3 doping was grown from a Li-rich melt (Li/Nb = 1.38, atomic ratio) by the Czochralski method in air atmosphere. The OH- absorption band was characterized by infrared transmittance spectra. The appearance of the 3466 cm-1 absorption band (2.89 mum) manifests that the composition of the grown crystal is close to the stoichiometric ratio. The photorefractive properties were measured by a two-wave coupling experiment. The measured results show that the Fe-doped near-stoichiometric LiNbO3 crystal has a larger exponential gain coefficient than the Fe-doped congruent LiNbO3 crystal. The remarkable gain can be attributed to the photovoltaic field being comparable with the effective limiting space-charge field.