准位相匹配铌酸锂波导倍频特性分析与优化设计

用标量有限元方法计算了周期性极化的铌酸锂光波导中模折射率和模场分布,并在计算中引入铌酸锂晶体折射率与温度变化的关系,分析了准位相匹配铌酸锂波导倍频效率与极化反转光栅周期、基频光波长、波导器件温度等关系.理论分析与实验结果符合得很好.在此基础上,分析了波导制作参数与倍频效率、光栅周期与晶体温度,以及温度带宽与光栅通光方向长度等关系,进而对铌酸锂波导倍频器件进行优化设计. 关键词： 铌酸锂 光波导 准位相匹配 有限元

Numerical analysis and optimization of quasi-phase-matched second-harmonic-generation in LiNbO3 waveguide

Scalar finite-element-method was used to calculate the effective index and mode field distribution in periodically poled LiNbO 3 waveguide, where the relationship of the refractive index of LiNbO 3 and its temperature was concerned. Based on the results, the relationship between quasi-phase-matched second-harmonic-generation (SHG) efficiency and the periodically poled grating period, fundamental wavelength, bulk temperature was analyzed, and the theoretical results fit well with the experiments. Furthermore, the dependences of converted SHG efficiency on the annealed proton exchanged waveguide parameter, the grating period on the crystal temperature, and the bandwidth of temperature and fundamental wavelength on the length of grating period were analyzed and optimized.