新的质子源质子交换制作的Z切LiNbO_3光波导特性

Z-Cut LiNbO_3 Optical Waveguides Formed in a New Proton Source

研究了用己二酸和苯甲酸的不同混合摩尔比作为质子源交换制作的 Z切 L i Nb O3光波导的表面折射率改变、波导深度、折射率分布等光学特性。结果表明 ,在交换温度为 2 30℃ ,交换时间为 6 h时 ,混合摩尔比较高时 ,波导为β4 相 ;较低时 ,为β3相。在β4 相时 ,混合摩尔比越大 ,波导的表面折射率改变和波导的深度越大 ;在β3相时 ,不同的混合摩尔比交换的波导光学特性差别不明显。用双晶 X射线衍射法对单苯甲酸和混合摩尔比为 6 0 %制作的光波导进行 X射线衍射。以上结果对波导器件的制作及理解波导折射率改变的物理机制提供了一些有用的信息。

The optical characteristics and waveguide index profiles of Z-cut LiNbO_3 optical waveguides which fabricated by using a new proton source formed by a mixture of adipic and benzoic acids with different values of the adipic-benzoic acid concentration ratio were studied.The experimental results show that the optical waveguides present β_4-phase when high concentration ratio, while present β_3-phase when relative low concentration ratio under the exchange temperature of 230℃ exchange time of 6 h. The higher the concentration ratio, the greater the surface refractive index change and waveguide depth of the optical waveguides in β_4-phase, and the difference of optical properties in β_3-phase is not significantly. The optical waveguides fabricated by using single benzoic acid and 60% ratio dilution were analyzed by double crystal X-ray diffraction. The results give useful information in making optical waveguides and to understand the physical mechanism of refractive index change in the LiNbO_3 optical waveguides.