Bijloo Falco, Murzyn Kevin, van Emmerik Floor, den Boef Arie J, Kraus Peter M, Koenderink A Femius
Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands.
Department of Physics of Information in Matter and Center for Nanophotonics, NWO-I Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
Nano Lett. 2024 Oct 2;24(41):12942-7. doi: 10.1021/acs.nanolett.4c03536.
We demonstrate all-optical modulation with a near-unity contrast of nonlinear light generation in a dielectric metasurface. We study third-harmonic generation from silicon Fano-resonant metasurfaces excited by femtosecond pulses at 1480 nm wavelength. We modulate the metasurface resonance by free carrier excitation induced by absorption of an 800 nm pump pulse, leading to up to 93% suppression of third-harmonic generation. Modulation and recovery occur on (sub)picosecond time scales. According to the Drude model, the pump-induced refractive index change blue-shifts the metasurface resonance away from the generation pulse, causing a strong modulation of third-harmonic conversion efficiency. The principle holds great promise for spatiotemporal programmability of nonlinear light generation.
我们展示了在介电超表面中具有接近单位对比度的非线性光产生的全光调制。我们研究了由波长为1480 nm的飞秒脉冲激发的硅法诺共振超表面产生的三次谐波。我们通过800 nm泵浦脉冲吸收诱导的自由载流子激发来调制超表面共振，导致三次谐波产生的抑制高达93%。调制和恢复发生在（亚）皮秒时间尺度上。根据德鲁德模型，泵浦诱导的折射率变化使超表面共振蓝移远离产生脉冲，从而对三次谐波转换效率产生强烈调制。该原理对于非线性光产生的时空可编程性具有很大的前景。
