Gao Xiaohui, Shim Bonggu, Downer Michael C
Opt Lett. 2019 Feb 15;44(4):779-782. doi: 10.1364/OL.44.000779.
We study theoretically harmonic generation from ionizing nano-clusters irradiated by intense few-cycle laser pulses and identify a Brunel-type harmonic generation mechanism that originates from subcycle ionization dynamics in clusters. Compared to Brunel harmonics in gases, the spectra are shifted toward odd-order harmonics of Mie frequency ω due to efficient excitation of Mie oscillations. Considering the appreciable single-cluster harmonic yield and the relaxed phase-matching condition in overdense clustered plasmas, clusters driven by few-cycle laser pulses can be a promising source of vacuum-ultraviolet radiation.
我们从理论上研究了强少周期激光脉冲辐照电离纳米团簇产生的谐波，并确定了一种源于团簇中亚周期电离动力学的布鲁内尔型谐波产生机制。与气体中的布鲁内尔谐波相比，由于米氏振荡的有效激发，光谱向米氏频率ω的奇次谐波方向移动。考虑到过密团簇等离子体中可观的单团簇谐波产率和宽松的相位匹配条件，由少周期激光脉冲驱动的团簇可能是一种很有前途的真空紫外辐射源。
