We developed a novel technique to evaluate the elasto-optic coefficients of electrooptic (EO) single crystals. Notably, this method uses the deformation of the crystal generated by the space charge formed by the electrons injected into the crystal. For the first time, to our knowledge, the coefficient p12 was quantified separately from p11 for KTa1-xNbxO3(KTN) with this method. Both the coefficients exhibit significant temperature dependence caused by polarization fluctuations. Genuine EO coefficients gg11 and gg12 were calculated by excluding photoelastic contributions from the nominal EO coefficients. gg12 was negligibly small compared to the nominal coefficient before the exclusion. This indicates that the conventional nominal coefficient gn12 is actually composed of strain-induced components but does not reflect the pure effect.

中文翻译：

---

电光晶体弹光系数的空间电荷辅助评价方法

我们开发了一种新技术来评估电光 (EO) 单晶的弹光系数。值得注意的是，这种方法利用了由注入晶体的电子形成的空间电荷产生的晶体变形。据我们所知，第一次使用这种方法对 KTa1-xNbxO3(KTN) 的系数 p12 与 p11 分开进行量化。这两个系数都表现出由极化波动引起的显着温度依赖性。真正的 EO 系数 gg11 和 gg12 是通过从名义 EO 系数中排除光弹性贡献来计算的。与排除前的名义系数相比，gg12 小到可以忽略不计。这表明常规标称系数 gn12 实际上由应变诱导分量组成，但并未反映纯效应。