Stegmaier Matthias, Pernice Wolfram H P
Opt Express. 2013 Nov 4;21(22):26742-61. doi: 10.1364/OE.21.026742.
While single-mode waveguides are commonly used in integrated photonic circuits, emerging applications in nonlinear and quantum optics rely fundamentally on interactions between modes of different order. Here we propose several methods to evaluate the modal composition of both externally and device-internally excited guided waves and discuss a technique for efficient excitation of arbitrary modes. The applicability of these methods is verified in photonic circuits based on aluminum nitride. We control modal excitation through suitably engineered grating couplers and are able to perform a detailed study of waveguide-internal second harmonic generation. Efficient and broadband power conversion between orthogonal polarizations is realized within an asymmetric directional coupler to demonstrate selective excitation of arbitrary higher-order modes. Our approach holds promise for applications in nonlinear optics and frequency up/down-mixing in a chipscale framework.
虽然单模波导在集成光子电路中普遍使用，但非线性光学和量子光学中的新兴应用从根本上依赖于不同阶模式之间的相互作用。在这里，我们提出了几种方法来评估外部和器件内部激发的导波的模式组成，并讨论了一种有效激发任意模式的技术。这些方法的适用性在基于氮化铝的光子电路中得到了验证。我们通过适当设计的光栅耦合器来控制模式激发，并能够对波导内部的二次谐波产生进行详细研究。在非对称定向耦合器内实现了正交偏振之间的高效宽带功率转换，以证明对任意高阶模式的选择性激发。我们的方法在芯片规模框架下的非线性光学和频率上/下混频应用中具有前景。
