基于周期极化晶体的QPM-SHG技术发展及其应用

随着新型高质量的非线性晶体的出现，准相位匹配技术成为非线性频率变换的最有效的方法。从周期极化晶体准相位匹配二次谐波发生器（QPM-SHG）的基本原理出发，简要介绍了实现周期极化晶体的方法和技术，总结了准相位匹配技术在光子学微结构晶体材料和波导材料中的最新研究进展和发展趋势，展望了用微结构波导QPM-SHG实现飞秒光纤光源的发展应用前景。

Technology and applications of QPM-SHG using periodically poled crystals

With the advent of the unique and high quality nonlinear optical crystals, quasi-phase-matching technique becomes the most effective method to realize nonlinear frequency conversion, and the quasi-phase-matching second harmonic generation (QPM-SHG) is a general approach to obtain visible emission from infrared regime. The basic principle of QPM-SHG and some methods and technique to fabricate periodically poled crystals were introduced.And the main problem of high effective frequency conversion using the versatile lithium niobate crystal was also analyzed. The emphasis was put on the recent progress on QPM-SHG technology. The prospect was proposed that QPM microstructures combined with the fiber laser source, which integrated the compactness, wavelength-tunablity and stability, would offer bright future, especially with the meet of QPM-SHG short pulse nonlinear photonic devices based on the fiber sources.