Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Opt Lett. 2009 Nov 15;34(22):3580-2. doi: 10.1364/OL.34.003580.
We describe quasi-phase-matched nonlinear interactions in materials that possess 4 symmetry, such as GaAs. 4 symmetry together with curved propagation geometries produce quasi phase matching (QPM) without need of external domain inversions. To improve efficiency of nonlinear optical mixing, 4 -QPM can be combined with resonant microcavities such as whispering-gallery-mode microdisks. All interacting waves must be resonant with the cavity, which leads to stringent tuning requirements. We show tuning behavior for second-harmonic generation in a GaAs microdisk cavity and estimate that, with milliwatt-level external pumping, approximately 0.1% power-conversion efficiency can be obtained with negligible higher-order nonlinear effects.
我们描述了在具有 4 对称性的材料（如 GaAs）中发生的准相位匹配非线性相互作用。4 对称性和弯曲的传播几何形状产生了无需外部畴反转的准相位匹配（QPM）。为了提高非线性光学混合的效率，可以将 4-QPM 与 whispering-gallery-mode 微盘等共振微腔结合使用。所有相互作用的波都必须与腔共振，这就导致了严格的调谐要求。我们展示了 GaAs 微盘腔中的二次谐波产生的调谐行为，并估计在外部泵浦功率为毫瓦级的情况下，可以获得约 0.1%的功率转换效率，而高阶非线性效应可以忽略不计。
