硅包层质子交换条形光波导的频率响应

Frequency response of silicon-claded proton-exchanged channel waveguides

退火质子交换工艺已成为一种制备低损耗铌酸锂光波导的重要技术。但目前对该类光波导传输特性的研究还不多。利用半矢量光束传播法,对硅包层X切退火质子交换铌酸锂条形光波导的频率响应特性进行了数值分析。给出了几种波导结构参数下的计算结果。结果表明,波导传输模式的衰减特性与波长相关。波导的衰减特性,可以通过调整波导表面中心处折射率增量,硅包层厚度,及缓冲层的折射率和厚度来控制。硅包层光波导可以用来制作光频滤波器。

The annealed proton-exchanged （APE） process has emerged as an important technique for the fabrication of low-loss optical waveguides in LiNbO3. However, the propagation characteristics of this kind of optical waveguides have not been effectively investigated. The propagation characteristics of a silicon-clad x-cut APE channel optical waveguide as a function of wavelength are investigated by the semi-vectorial beam propagation method. Results for several different waveguide parameters are shown. The results obtained show that attenuation of the propagating mode in this waveguides is highly dependent on wavelength. Moreover, this attenuation characteristic can be controlled by waveguide parameters such as the surface refractive index increment, the thickness of silicon-cladding and the thickness and the refractive index of the buffer layer. As a result, the silicon-clad proton-exchanged optical waveguides can be used as optical frequency filters.