2015: Ultrafast all-optical switching with magnetic resonances in nonlinear dielectric nanostructures

MSU physicists (group of Prof. Andrey Fedyanin) in collaboration with group of Prof. Yuri Kivshar (The Australian National University) demonstrated experimentally ultrafast all-optical switching in subwavelength nonlinear dielectric nanostructures exhibiting localized magnetic Mie resonances.

In this work amorphous silicon nanodisks were used to achieve strong self-modulation of femtosecond pulses with a depth of 60% at picojoule-per-disk pump energies. In the pump−probe 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. It was also shown 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.

The results of this work have been published in: M.R. Scherbakov, P.P. Vabishchevich, A.S. Shorokhov, K.E. Ching, D.-Y. Choi, I. Staude, A.E. Miroshnichenko, D.N. Neshev, A.A. Fedyanin, and Yu.S. Kivshar, “Ultrafast all-optical switching with magnetic resonances in nonlinear dielectric nanostructures”, Nano Letters 15, 6985 (2015).