沿光轴通光的LiNbO_3的横向电光调制特性

LiNbO_3 transverse electro-optical modulation characteristics for light pass along optical axis

为了克服现有电光器件的缺陷,选取晶体生长工艺成熟、价格低廉、折射率及电光系数较大的LiNbO3作为电光晶体材料,研究了沿其光轴方向通光的横向电光效应。加工制作了x切、(xzl)45°切和y切3种不同切型的横向电光调制器,并对他们的调制性能做了实验分析。研究结果表明,沿LiNbO3光轴方向通光的横向电光调制有相同的电光参量,折射率感应主轴的位置与电场方向有关;3种不同切型的横向体电光调制器的零场泄露均很小,静态消光比均优于1 000∶1,半波电压实测值与理论值的相对误差不超过1.7%;相同调制电压下,它们的调制深度相同,且调制性能稳定。该项研究可为该类电光调制器件的设计和应用提供参考,拓展它们在光通信和光学测量领域的应用。

To overcome the defects of existing electro-optical devices,the LiNbO3 with advantages of mature growth process,low prices,large refractive indexes and large electro-optical coefficients was selected as an electro-optical material,and its transverse electro-optical effect for light pass along optical axis was researched.Then,three kinds of transverse electro-optical modulators with x-cut,（xzl）45°-cut and y-cut were fabricated,and their modulation characteristics were analyzed experimentally.The results indicate that the transverse electro-optical effects that light passes along optical axis have the same electro-optical parameters,and the refractive index induced spindle position is related to the direction of electric field.The three kinds of transverse electro-optical modulators with different cut modes all show the lower zero-field leakages,their static extinction ratios exceed1 000∶1and the relative error of half-wave voltage between measured value and theoretical value is less than 1.7%.Under the same modulation voltage,these modulators give the same modulation depths and stable modulation characteristics.The research provides references for design of this kind of electro-optical modulation devices,and will expands their applications in optical communications and optical measurement fields.