In a previous Letter [Phys. Rev. Lett. 96, 123401 (2006)] we have shown by means of three-dimensional particle-in-cell simulations and a simple rigid-sphere model that nonlinear resonance absorption is the dominant collisionless absorption mechanism in the intense, short-pulse laser cluster interaction. In this paper we present a more detailed account of the matter. In particular we show that the absorption efficiency is almost independent of the laser polarization. In the rigid-sphere model, the absorbed energy increases by many orders of magnitude at a certain threshold laser intensity. The particle-in-cell results display maximum fractional absorption around the same intensity. We calculate the threshold intensity and show that it is underestimated by the common over-barrier ionization estimate.
Harmonic emission from cluster nanoplasmas subject to intense short laser pulses
研究了短脉冲强红外激光作用下团簇纳米等离子体的谐波辐射。在以前的出版物[M。Kundu等人，Phys. Rev. A 76，033201（2007）]，我们报道了粒子单元模拟结果，其显示当电离和膨胀团簇的Mie等离子体频率与相应的谐波频率共振时，低阶谐波的共振增强。同时，我们发现，高次谐波几乎不存在于光谱中，即使在高强度。目前的文件是集中在分析建模的过程中。我们发现，由于非线性共振的动力学随机性抑制高次谐波的发射。
Rare-gas clusters in intense VUV, XUV and soft x-ray pulses: Signatures of the transition from nanoplasma-driven cluster expansion to Coulomb explosion in ion and electron spectra
