Zhang S G, You W C, Ma X R, Wang Q Y
Opt Express. 2014 Jun 30;22(13):16222-31. doi: 10.1364/OE.22.016222.
The authors report the filamentary waveguide formation and the significant spectral broadening based on periodically poled lithium niobate substrate. The modified morphology contributes to the combined effects of optical diffraction and self-focusing with the dependence on pulse intensity. Up to 4 times broadening of the FF wave and about 47 nm spanning of the SH wave with the pump power of 19.5 mW are achievable under 1550 nm excitation. Spectral evolution by cubic nonlinearity inside the waveguide has been obtained numerically, and provides a reasonable agreement with the experimental results.
作者报道了基于周期性极化铌酸锂衬底的丝状波导形成和显著的光谱展宽。改进后的形态有助于光学衍射和自聚焦的综合效应，且依赖于脉冲强度。在1550 nm激发下，泵浦功率为19.5 mW时，FF波可实现高达4倍的展宽，SH波可实现约47 nm的跨度。通过数值计算得到了波导内部三次非线性引起的光谱演化，与实验结果具有合理的一致性。
