Dispersion and anisotropy of thermo-optic coefficients in tetragonal GdVO4 and YVO4 laser host crystals

作者:Loiko Pavel A; Yumashev Konstantin V*; Matrosov Vladimir N; Kuleshov Nikolai V
来源:Applied Optics, 2013, 52(4): 698-705.
DOI:10.1364/AO.52.000698

摘要

A detailed experimental study of dispersion and anisotropy of thermo-optic coefficients dn/dT and thermal coefficients of the optical path W = dn/dT + (n - 1)alpha is performed for tetragonal YVO4 and GdVO4 laser host crystals by a laser beam deviation method. It is supported by theoretical description of thermo-optic effects, taking into account the volumetric thermal expansion effect and the temperature dependence of electronic bandgap E-g. Linear thermal expansion coefficients a were also determined by a dilatometric technique. Thermo-optic dispersion formulas describing temperature variation of the refractive index and the thermal lens effect are derived for a wide spectral range of 0.4-2 mu m. It allows us to estimate the values of Eg and dEg/dT for the studied crystals. The influence of materials parameters and pumping conditions on thermal lens properties is discussed, revealing the significant impact of anisotropic and temperature-dependent thermal conductivity.

  • 出版日期2013-2-1