We experimentally demonstrate coherent control of the nonlinear response of optical second harmonic generation in resonant nanostructures beyond the weak-field regime. Contrary to common perception, we show that maximizing the intensity of the pulse does not yield the strongest nonlinear power-law response. We show this effect emerges from the temporally asymmetric photoinduced response in a resonant mediated noninstantaneous interaction. We develop a novel theoretical approach which captures the photoinduced nonlinearities in resonant nanostructures beyond the two photon description and give an intuitive picture to the observed noninstantaneous phenomena.

中文翻译：

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共振纳米结构中非瞬时非线性幂律响应的相干控制

我们实验证明了共振纳米结构中光学二次谐波产生的非线性响应的相干控制超出了弱场范围。与通常的看法相反，我们表明最大化脉冲强度不会产生最强的非线性幂律响应。我们显示出这种效应是由共振介导的非瞬时相互作用中的时间不对称光诱导反应产生的。我们开发了一种新颖的理论方法，该方法捕获了超出两个光子描述的共振纳米结构中的光诱导非线性，并对观察到的非瞬时现象给出了直观的图像。