Bi Zhuan-Fang, Rodriguez Alejandro W, Hashemi Hila, Duchesne David, Loncar Marko, Wang Ke-Ming, Johnson Steven G
School of Physics, Shandong University, Jinan, Shandong 250100, China.
Opt Express. 2012 Mar 26;20(7):7526-43. doi: 10.1364/OE.20.007526.
By directly simulating Maxwell's equations via the finite-difference time-domain (FDTD) method, we numerically demonstrate the possibility of achieving high-efficiency second harmonic generation (SHG) in a structure consisting of a microscale doubly-resonant ring resonator side-coupled to two adjacent waveguides. We find that ≳ 94% conversion efficiency can be attained at telecom wavelengths, for incident powers in the milliwatts, and for reasonably large bandwidths (Q ∼ 1000s). We demonstrate that in this high efficiency regime, the system also exhibits limit-cycle or bistable behavior for light incident above a threshold power. Our numerical results agree to within a few percent with the predictions of a simple but rigorous coupled-mode theory framework.
通过有限时域差分（FDTD）方法直接模拟麦克斯韦方程组，我们通过数值方法证明了在由一个与两个相邻波导侧耦合的微尺度双谐振环形谐振器组成的结构中实现高效二次谐波产生（SHG）的可能性。我们发现，对于毫瓦级的入射功率和合理的大带宽（Q约为1000），在电信波长下可以实现≳94%的转换效率。我们证明，在这种高效 regime 中，对于高于阈值功率的入射光，该系统还表现出极限环或双稳态行为。我们的数值结果与一个简单但严格的耦合模理论框架的预测在百分之几的范围内一致。
