0.91Pb(Zn1/3Nb2/3)O3-0.09PbTiO 3(PZN-9%PT) single crystals with different orientations are investigated by using a spectroscopic ellipsometer,and the refractive indices and the extinction coefficients are obtained.The Sellmeier dispersion equations for the refractive indices are obtained by the least square fitting,which can be used to calculate the refractive indices in a low absorption wavelength range.Average Sellmeier oscillator parameters E o,λ o,S o,and E d are calculated by fitting with the single-term oscillator equation,which are related directly to the electronic energy band structure.The optical energy bandgaps are obtained from the absorption coefficient spectra.Our results show that the optical properties of [001] and [111] poled crystals are very similar,but quite different from those of the [011] poled crystal.
采用助溶剂法生长了掺杂量分别为0.1wt%和0.01wt%的0.67PMNT-0.33PT单晶.利用二波耦合实验研究了掺铁的弛豫铁电单晶0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3(PMN-PT)的光折变性能.本文测了样品的消光光谱、电光系数、光诱吸电场和光电.最大的增益系数达了21 cm 1,是无掺杂的PMN-PT晶体的两倍.光栅形成速率随铁浓度的升高而降低.
