Ultrafast All-Optical Switching with Magnetic Resonances in Nonlinear Dielectric Nanostructures

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• 作者：Maxim R. Shcherbakov ; Polina P. Vabishchevich ; Alexander S. Shorokhov ; Katie E. Chong ; Duk-Yong Choi ; Isabelle Staude ; Andrey E. Miroshnichenko ; Dragomir N. Neshev ; Andrey A. Fedyanin ; Yuri S. Kivshar
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：October 14, 2015
• 年：2015
• 卷：15
• 期：10
• 页码：6985-6990
• 全文大小：363K
• ISSN：1530-6992

文摘

We demonstrate experimentally ultrafast all-optical switching in subwavelength nonlinear dielectric nanostructures exhibiting localized magnetic Mie resonances. We employ amorphous silicon nanodisks to achieve strong self-modulation of femtosecond pulses with a depth of 60% at picojoule-per-disk pump energies. In the pump鈥損robe measurements, we reveal that switching in the nanodisks can be governed by pulse-limited 65 fs-long two-photon absorption being enhanced by a factor of 80 with respect to the unstructured silicon film. We also show that undesirable free-carrier effects can be suppressed by a proper spectral positioning of the magnetic resonance, making such a structure the fastest all-optical switch operating at the nanoscale.